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A global assessment of Holistic Planned Grazing™ compared with season-long, continuous grazing: meta-analysis findings AFRICAN JOURNAL OF RANGE & FORAGE SCIENCE
Abstract
It has been claimed that Holistic Planned Grazing™ (HPG), a type of rotational grazing, can increase productivity in rangelands and reverse climate change while doubling the stocking rate, mainly through the impact of densely bunched animals on primary production. Previous reviews have found similar or greater plant and animal production in continuous (season-long) compared with rotational grazing. Here season-long continuous grazing is compared with HPG alone to explore the evidence for animal impact. Three quantitative meta-analysis models were used to assess data sets from literature between 1972 and 2016. Weighted mean differences (effect sizes) between HPG and continuous grazing showed that there was no difference in plant basal cover, plant biomass and animal gain responses (p > 0.05). Thus, from the balance of studies, if animal impact is occurring during HPG, it has no effect on production. As interesting as the overall result is the significant between-study heterogeneity assessed using Cochran’s Q (p = 0.007 to <0.0001). Studies with positive effect sizes tended to have higher precipitation (p < 0.05), suggesting that only some rangelands have the resources to support HPG. Furthermore, there is scope for investigating the impact of HPG on socio-ecological aspects of rangelands, such as management.
... Results of the review are summarised in Table 3. With respect to regenerative grazing, there has been a growing body of work looking at the benefits of the practice over the last decade, some of which have been synthesised in meta analyses (see for example, [58] [59] [60]. The overall direction of the existing evidence for impacts of regenerative grazing practices on natural capital relative to conventional grazing management is positive, although the effect is weak (mean direction of the evidence 0.3). ...
... Practices such as regenerative grazing or silvopastoral systems are often cited as having the capacity to restore or build natural capital by improving soil health, capturing and using available water resources more efficiently and increasing the sequestration and storage of carbon [66] [67] [68] [69] [70] while at the same time offering minimal or even positive impacts on production [71] [38]. However, evidence for these claims is often anecdotal, qualitative or limited leading to questions being raised about the veracity of these claims (for example see [58]. In this review we have attempted to collate the evidence for the impacts of grazing management practices across a large number of natural capital indicators. ...
... However, the caveat on this statement is that in this assessment for many of the natural capital indicators, the evidence base was quite limited. The role that regenerative grazing can play in managing various aspects of natural capital has been the subject of number of specific meta-analyses [58] [59] [73]. Generally, these meta-analyses have found that the benefits of regenerative grazing are often minimal, patchy or even contradictory. ...
Using a weight of evidence approach, natural capital associated with regenerative grazing and silvopastoral systems were compared with those associated with conventional grazing systems. The aim of this review was to understand how grazing management influenced 16 natural capital indicators likely to be material from an economic and sustainability perspective for grazing enterprises. The review found that moderate to high levels of grazing degrades natural capital relative to lighter grazing. In relation to regenerative grazing, responses were less clear. Regenerative grazing may have a positive impact, particularly in relation to soil biodiversity and liveweight gain. However, evidence effect size may be small and may take years to be properly realised. For 12 of the 16 indicators reviewed, natural capital outcomes were inconclusive, even though for five of these indicators, the evidence base was robust. For silvopastoral systems, there was evidence suggesting this type of grazing could improve natural capital. Although data underpinning many natural capital outcomes associated with grazing is incomplete, it should not be interpreted as a lack of benefit (ie improved natural capital and enterprise productivity). Rather, it highlights shortcomings in the evidence. Few studies have fully accounted for the benefits of management practice change on natural capital and the productivity of the enterprise simultaneously and over a sufficient period to observe change. This was particularly evident in relation to carbon storage. While there have been many studies that have examined changes in individual stocks, e.g. soil carbon or emissions in relation to grazing management, few studies have examined whole farm carbon balance. Increased adoption of processes such as natural capital accounting, although in their infancy, could help to address this challenge and facilitate a more systematic analysis of enterprise natural capital and financial performance.
... Based on a review of the published grazing experiments, Briske et al. (2008) concluded that, generally, RG performed no better than CG, with 87%, 92%, and 84% of the cited studies supporting this conclusion in terms of plant production, animal performance, and animal production, respectively. Additionally, Hawkins (2017) assessed studies between 1972 and 2016 and found no differences in plant and animal responses between holistic planned grazing and RG. The conclusion that RG performs no better or even worse than CG in different aspects has also been reached by some recent studies ( Wilmer et al. 2018 ;Venter et al. 2019 ;Augustine et al. 2020 ). ...
... We also obtained 30-y (1988-2017) county-level average precipitation and growing season minimum temperature data from the National Oceanic and Atmospheric Administration. Previous studies have shown that soil conditions can affect RG benefits ( Teague and Foy 2004 ) and that climate conditions also affect the efficacy of RG Wolf and Horney, 2016 ;Hawkins, 2017 ;Gosnell et al. 2020b ). Given the previous findings, we expect adoption of high management intensity to be influenced by weather and soil conditions that magnify the benefits of such practices. ...
... The lack of strict correspondence between the two indicators illustrates the complexity of grouping ranchers and further emphasizes the need for robustness check using different grouping criteria. Using both grouping criteria, we found no differences between the extensive and intermediate groups in terms of grazing management outcomes, which corresponds with some previous research conclusions that there is no consistent difference in grazing management outcomes with CG and RG ( Briske et al. 2008 ;Hawkins 2017 ;Venter et al. 2019 ;Augustine et al. 2020 ). However, our results also emphasize the potential benefits of using intensive management practices to improve grazing management outcomes ( Lawrence et al. 2019 ;Teague and Kreuter 2020 ;Mosier et al. 2021 ;Apfelbaum et al. 2022 ). ...
... Numerous terms have been used to describe potential components of regenerative grazing (RG) and landholders may use one or more approaches at different parts of their property over different time periods. Some of the terms include spelling or strategic rest (Ash et al. , 2011, rotational grazing (Briske et al. 2008), time controlled grazing (Sanjari et al. 2008), intensive rotational grazing (Badgery 2017), short duration rotational grazing , cell grazing (McCosker 2000;Richards and Lawrence 2009), Holistic Management or Holistic Planned grazing (Savory 1983;Hawkins 2017;Gosnell et al. 2020) and adaptive multi-paddock per herd grazing (Teague and Kreuter 2020), to name a few. Many of the principles outlined in RG are the same as those applied in more traditional bestpractice grazing land management (GLM) approaches, and many of the terms used are common to grazing systems and management generally. ...
... The large number of terms used to describe RG components can be confusing, and it can be difficult to determine whether there are differences in the various approaches, or whether they are simply the same thing with a different name. Either because of the differences in epistemology and nomenclature (Gosnell et al. 2020), or the diverse landscapes on which these practices have been applied, there has been considerable controversy regarding the relative benefits of these methods for grazing production, soil and land condition, and ecosystem function (Abdel-Magid et al. 1987;Hart et al. 1993;Briske et al. 2008Briske et al. , 2011Briske et al. , 2014Teague et al. 2013;Hawkins 2017;Hawkins et al. 2017;Teague and Barnes 2017;Teague and Kreuter 2020). It is not the intention of this paper to focus on the detailed management activities employed because there are several recent reviews of this topic and readers are encouraged to access this literature for more detail (e.g. ...
... For example, de Villiers et al. (2014) found that farmers practicing Holistic Management™ had a higher social capital in that they participated more in groups, which is likely to lead to increased learning and adaptive behaviour. Thus, the farm-level benefits besides production, i.e. socioecological aspects, should be included in future research on production rangelands (Hawkins 2017). Landholders involved in this study also suggested that there are long-term financial gains to be made from these approaches, and a targeted economic analysis to quantify the gross marginal gains would be highly beneficial. ...
Regenerative grazing, which generally involves some form of rotational grazing with strategic rest, is increasingly seen as a profitable management approach that will accelerate landscape recovery. However, there is limited quantitative evidence supporting the benefits of this approach in northern Australia. This space-for-time study collected vegetation and soil data from a range of properties in the Burdekin catchment in Queensland that have implemented regenerative grazing strategies for between 5 and 20 years. Data were also collected at adjacent control sites that did not undergo regenerative grazing, but where more traditional continuous set-stocking grazing approaches were applied. Coincident data were also collected from several sites where grazing had been excluded for ~30 years. Data suggested that improvements in vegetation, soil and land condition can be obtained from implementing regenerative grazing principles, although it is likely to take at least 3–5 years, and up to 15–20 years for statistically significant improvements to be measurable at a site, particularly for areas that are moving from a degraded baseline condition. Vegetation attributes such as plant biomass and basal area and litter incorporation all appeared to be better surrogates than percentage ground cover for representing improved landscape condition and soil health. Sites that maintained remotely sensed percentage ground cover at or above the minimally disturbed reference benchmark levels for >10 years, as well as having statistically higher biomass, basal area and litter, had significant increases in total nitrogen (TN) and soil organic carbon (SOC) relative to the local control site. Although there are indications that regenerative grazing can lead to improvements in land condition, this study does not enable us to conclude whether regenerative grazing will accelerate improvements compared with other best-practice grazing land management (GLM) approaches, and further research on the social and economic dimensions of regenerative grazing is needed.
... However, replicated empirical assessment of the ecological consequences of AMP grazing is limited to studies small in scale and with treatments having more restricted adaptivity compared to actual working ranches (Teague et al., 2013). Although there exists some evidence that in certain climates, AMP grazing is associated with increased aboveground production, its influence on plant diversity is largely unknown (Hawkins, 2017). This knowledge gap is due to both the generality of theoretical frameworks explaining grazing effects on plant communities (i.e. the intermediate disturbance hypothesis, Connell, 1978), and the overall lack of empirical tests of such conceptual theories linking grazing effects to ecosystems. ...
... grazing disturbance, grazing system, intensive grazing, introduced species, native species, plant community, plant diversity (Hawkins, 2017). Even if AMP grazing does not lead to increases in grazing intensity, its underlying intent of causing uniform grazing within each paddock is expected to modify plant heterogeneity and associated diversity. ...
... Grey lines connect paired ranch points, illustrating total directionality of response to grazing management per area per time (Sherren & Kent, 2019), the equivalent stocking rates is understandable. From a social standpoint, AMP grazing is often publicized as enabling higher stocking rates (Hawkins, 2017), though such differences in stocking rates were not found in this particular study. This contrast between expectation and application highlights the value of measuring potential environmental consequences of modified grazing systems from working, rather than hypothetical, cattle operations (Venter et al., 2019). ...
Grassland plant community structure and function are dependent on the type, timing, frequency and intensity of disturbance. Grazing systems employing dense herds of livestock for short periods of time (e.g. Adaptive Multi‐paddock Grazing; AMP) are gaining popularity as a potentially sustainable practice. Effects of AMP systems on plant diversity and composition are unknown, though theory provides some expectations. Spatially homogeneous grazing used by AMP may be a uniform ecological filter, thereby lowering plant diversity; alternatively, the AMP practice of using multiple paddocks might enhance habitat heterogeneity. Maintaining plant diversity, particularly of native species, is a key aspect of sustainability. As such, an understanding of the real‐world effects of AMP grazing is needed.
We studied grasslands within 18 pairs of ranches across the northern Great Plains. Ranches managed under AMP were paired with a neighbouring ranch (N‐AMP) using regionally representative grazing practices. We collected surveys of management practices and conducted 2 years of on‐farm sampling to identify plant composition and diversity.
Ranch management practices used by self‐identified AMP ranchers differed significantly (p < 0.1) from those used on neighbouring ranches, with higher stocking densities (number of animals per area at a single time) but not stocking rates (total number of animals per unit time per area) on AMP relative to N‐AMP ranches.
There were fewer plant species in AMP grasslands at both the plot and landscape scales compared to N‐AMP ranches despite no overall difference in plant community composition. Management type did not alter the variability of plant community composition (beta diversity) or plot‐level species evenness. Although there were trends for lower diversity of native and introduced species at both spatial scales, a significant effect was found only for native species at the landscape scale.
Synthesis and applications. The impacts of AMP grazing system management were limited to a minor reduction in plant diversity, with a modest decline in native species richness. We conclude that the benefits of AMP grazing in the northern Great Plains do not include the maintenance of plant diversity, and this system could hinder the conservation of remaining native plant species.
... Scientific studies find no grounds for the claims of increased production or soil organic carbon (SOC). Indeed, claims for the benefits of rotational grazing (including HPG), have been challenged since the 1950's (Sampson, 1951) and more recently by many studies and references therein (O'Reagain and Turner, 1992;Briske et al., 2008Briske et al., , 2011aHawkins, 2017;Venter et al., 2019aVenter et al., , 2019bVenter et al., , 2020. However, proponents of HM criticize the small scale of some studies, stating that benefits only emerge on large, working livestock farms / ranches (Teague et al., 2013). ...
... Based on abstracts and full texts, peerreviewed articles were selected that compared HPG and other patterns of grazing at defined stocking rates, or more broadly assessed management of mammalian herbivores on production, climate and society, with a focus on farm-scale studies. The aim was not to conduct a metaanalysis of agricultural-style trials that tested how HPG influences production as this has been previously conducted (Hawkins, 2017) while too few studies about HPG and climate or social studies exist. The studies encompassed a range of locations globally, livestock and wildlife types, and grazing management types that were adaptive or not ( Table 1). ...
... Claims about increased production and climate resilience with HM are unfounded based on farm-scale studies, which are also supported by many experimental trials and reviews (Briske et al., 2011a;Hawkins, 2017). This is not surprising because Venter et al. (2019b) found that animal behaviour (time spent grazing, walking or resting; proximity to one another, dung trampling, and selectivity at plant scale) did not differ. ...
Holistic Management (HM) is claimed to increase production of plants and animals while also increasing soil organic carbon under all conditions in all habitats. Peer-review literature does not support these claims, but several studies report social benefits. Proponents of HM have criticized the small-scale of some studies (less than 2 ha), stating that production and climate benefits only emerge on large working farms (2–66 ha or larger, our size definitions). Here we summarize the conclusions from 22 peer-reviewed studies, focusing on farm-scale studies, and the few social and soil carbon studies from across the globe. Conclusions were synthesized into a diagram showing how grazing pattern (or density), stocking rate and animal type influence biology, climate resilience, and agricultural economics, as well as how HM’s management component affects society. This synthesis confirms that HM’s intensive grazing approach either has no effect or reduces production, as evidenced by farm-scale studies in United States of America, Argentina and South Africa, thus negating the claim by HM proponents that there is a difference between ‘the science and the practice’. Seven peer-reviewed studies show that the potential for increased carbon sequestration with changed grazing management is substantially less (0.13–0.32) than the 2.5–9 t C ha⁻¹ yr⁻¹ estimated by non-peer-review HM literature. Five studies show that HM provides a social support framework for land users. The social cohesion, learning and networking so prevalent on HM farms could be adopted by any farming community without accepting the unfounded HM rhetoric, and governments could allocate funds to train extension agents accordingly. A future focus on collaborative adaptive farm management and other innovations will be more helpful than any further debate about grazing density.
... Given the inherent complexity of grazing strategies available, varying perspectives exist on whether, when, and how variation in grazing alters grassland function. For example, several studies conclude that the benefits of rotational grazing for maintaining grassland production and range condition may not be as large and consistent as previously thought, with the majority of studies reporting no difference between areas subject to rotational and continuous grazing ( Holechek et al. 1999 ;Briske et al. 2008 ;Hawkins 2017 ). In contrast, McDonald et al. (2019) concluded that strategic rest appeared capable of enhancing ground cover and anhttps://doi.org/10.1016/j.rama.2021.04.010 1550-7424/© 2021 The Society for Range Management. ...
... What remains unclear is the extent to which variation in nuanced grazing practices among these cattle ranches regulates grassland responses, such as the length of grazing or subsequent rest periods ( Heitschmidt and Taylor 1991 ). Advocates of AMP (and holistic) grazing highlight the need for high stock densities (i.e., animals per unit land area) for short periods at the optimal time during the growing season to maximize benefits ( Savory and Butterfield 1999 ;Teague et al. 2011Teague et al. , 2013, a response that can vary with environmental conditions ( Hawkins 2017 ). ...
... Given this result, it would appear that the use of individual grazing metrics may be a superior means to characterize the real-world variance in management practices used by cattle ranches, particularly in comparison with the nominal classes of "AMP" or "n-AMP." This finding, coupled with high environmental variability, might explain the difficulty of generalized "systems type" research in detecting significant effects in field studies (Hawkins et al. 2017). ...
Significant interest exists in the potential for specialized grazing systems, including adaptive multipaddock (AMP) grazing, to enhance grassland health and function. However, specific pasture management practices associated with AMP grazing at the ranch level remain poorly understood in comparison with more regionally representative management systems. As part of a larger study examining grazing effects on soil carbon, greenhouse gases, and other ecosystem attributes, here we report on differences in disturbance history and grazing management practices on a sample of AMP operators and their neighboring (n-AMP) ranches at 32 paired sites across the prairie provinces of western Canada. Most ranches studied (77.5%) relied on pastures composed of introduced (seeded) forage. On average, the AMP ranches surveyed were larger in size, supported greater animal numbers, and were more likely to use seeded forages comprising diverse mixes. Relative to n-AMP ranches, AMP ranches used 18.6-fold higher average stock densities in smaller paddocks (22.3 vs. 120.7 ha) while grazing over a grazing season that was 76 d longer, although computed stocking rates remained similar (P ≥ 0.10). AMP operators specifically used much shorter grazing periods (2.8 d) during the early growing season (i.e., before August 1) that were followed by a prolonged rest period (69 d) and could be used to compute a rest-to-grazing ratio for the first half of the grazing season for all ranches. This ratio, along with cattle stock density computed at the pasture scale, exhibited the greatest potential to differentiate the two groups of ranchers. Finally, both groups, and in particular ranchers within the AMP group, demonstrated high variability in management practices among individual operators, highlighting the importance of using specific management metrics rather than generalized descriptors of “grazing system type” to interpret their influence.
... Purported benefits of grazing at increased stocking density over shorter time frames include increased uniformity of forage utilization within a pasture (i.e., less selective grazing by animals), longer intervening periods of pasture rest (nongrazing), increased production of palatable forage species, and greater heterogeneity of vegetation structure among pastures ( Teague et al. 2013 ). Syntheses of numerous experiments examining rotational grazing strategies based on fixed schedules (i.e., nonadaptive decision making) have not shown benefits of rotational grazing to forage or livestock production ( Briske et al. 2008 ;Hawkins 2017 ). We recently compared livestock production under continuous, seasonlong grazing versus multipaddock rotational grazing implemented using an adaptive approach and found that cattle in the latter treatment gained 12 −16% less weight each year . ...
... Second, managers who increase stock densities and rotate cattle among pastures often also employ adaptive management when designing rotation sequences and decision triggers for herd movement. Therefore ranch-scale responses of forage and livestock production to changes in stocking densities are often confounded with the degree to which managers monitor changing conditions and modify management actions ( Teague et al. 2013 ;Hawkins 2017 ;Augustine et al. 2020 ). Consequently, past experimental grazing research might not have demonstrated the purported benefits of rotational grazing because the adaptive decision making of an experienced manager had been excluded ( Briske et al. 2011 ). ...
... Our results suggest that the benefits of CAM as applied to multipaddock rotational grazing arose from the Stakeholder Group's ability to incorporate adaptive movements of livestock across a spatially and temporally variable landscape, rather than the simple alternation of grazing and rest ( Briske et al. 2008 ;Hawkins 2017 ). Relative to a nonadaptive approach, and excluding drought conditions, CAM's increased livestock production at the high stocking density was a direct outcome of its unique decision process bolstered by knowledge of varying soil types, ecological sites ( Reynolds et al. 2019 ), and plant communities in this landscape. ...
Collaborative adaptive management (CAM) is hypothesized to benefit management of rangeland ecosystems, but the presumed benefits have seldom been quantified, and never in a multipaddock rotational grazing system. Here, we evaluated average daily weight gain (ADG) of livestock (kg steer⁻¹ d⁻¹) in four grazing management treatments during the summers of 2016−2018 in a semiarid shortgrass steppe. These four treatments had the same stocking rate but differed in stocking densities. The three lowest stocking densities were implemented using nonadaptive grazing management, while the highest stocking density was implemented using CAM by an 11-member Stakeholder Group. Three of the four treatments used multipaddock rotational grazing. Growing season precipitation varied from drought in 2016 to near average in 2017 and dry in 2018. During nondrought years, ADG under nonadaptive grazing declined linearly as stocking density increased from low to high. This relationship was not significant during drought (2016). CAM increased absolute livestock production by 0.13 to 0.19 kg steer⁻¹ d⁻¹ in nondrought years, or a 23−25% relative increase in ADG. This benefit of CAM arose from the Stakeholder Group's ability to rotate cattle in response to spatiotemporal heterogeneity across the landscape—i.e., the ability to graze the “right pastures at the right time.” Multiplying the additional grazing season livestock gains achieved through CAM by the monetary value of gains (48.16 to $55.54 per steer annually, as compared with revenues from nonadaptive multipaddock rotational grazing under nondrought conditions. These results indicate that CAM, supported with substantial and timely monitoring data, can minimize decreases in livestock production associated with high stocking densities used in multipaddock rotation systems. However, in this experimental context, the economic benefits of increased livestock production associated with CAM were likely insufficient to offset the substantial cost of this approach.
... They further suggested that stocking rate, rest period, and livestock exclusion may represent the best management strategies for restoring native grassland productivity, ecological condition, and sustainability. Hawkins (2017) reported that holistic management is a goal-setting process that may be used to define quality of life, form of production, and a future resource base for the landowner. It was concluded from peer-reviewed publications that holistic management, also termed holistic planned grazing, does not improve production; thus, this management approach does not warrant the additional inputs of infrastructure and labor. ...
... It was concluded from peer-reviewed publications that holistic management, also termed holistic planned grazing, does not improve production; thus, this management approach does not warrant the additional inputs of infrastructure and labor. Hawkins (2017) also reported that other terminology for holistic management may include holistic resource management or the Savory (Savory, 1983) method. Allen et al. (2011) defined mob stocking as "a method of stocking at a high grazing pressure for a short time to remove forage rapidly as a management strategy." ...
Grazing management and stocking strategy decisions involve the manipulation of grazing intensity, grazing frequency, and timing of grazing to meet specific objectives for pasture sustainability and economic livestock production. Although there are numerous stocking systems used by stakeholders, these methods may be broadly categorized as either continuous or some form of rotational stocking. In approximately 30 published experiments comparing continuous vs. rotational stocking, there was no difference in liveweight gain per animal between stocking methods in 66% of studies. There was no difference in gain per ha between methods in 69% of studies, although for gain per ha the choice of fixed or variable stocking rate methodology affected the proportion (92% for fixed; 50% for variable). Despite these experimental results showing limited instances of difference between rotational and continuous stocking, rotational strategies (e.g., “mob stocking” or “regenerative grazing”) have received what appears to be unmerited acclaim for use for livestock production. Many proposed “mob stocking” or “regenerative grazing” systems are based on philosophies similar to high intensity-low frequency stocking, including provision for > 60 days of rest period from grazing. In addition, grazing management practitioners and stakeholders have voiced and proposed major positive benefits from rotational stocking, “mob stocking”, or “regenerative grazing” for soil health attributes, carbon sequestration, and ecosystem services, without experimental evidence. The perceptions and testimonials supporting undefined stocking systems and methods have potential to mislead practitioners and result in economic disservices. Thus, we suggest that scientists, Extension-industry professionals, and producers seek replicated experimental data as the basis for predicting outcomes of grazing decisions.
... Numerous studies aimed to assess the ecological impacts of high-density grazing systems versus conventional systems on rangeland status. Reviews of literature (Holechek et al., 2000;Teague et al., 2013;Briske et al., 2014;Nordborg, 2016;Hawkins, 2017;Gosnell et al., 2020;Hawkins et al., 2022) indicate that the evidence of high-density grazing systems providing the claimed ecological benefits is rather mixed, at best, especially when high-density grazing is compared with other forms of rotational grazing. While high-density grazing in semi-arid grasslands may increase organic matter in the upper part of the soil profile (Chaplot et al., 2016), it may also result in soil compaction, reduced soil aggregate stability and decreased soil moisture (Chamane et al., 2017;Roberts and Johnson, 2021). ...
... A switch from conventional to high-density grazing systems does require additional investments in farm infrastructure, livestock and more intensive forms of management (Teague et al., 2013). Evidence from the literature that high-density grazing systems lead to higher productivity and profitability per unit area is scarce and inconclusive (Hawkins, 2017;Venter et al., 2019;Derner et al., 2021;Hawkins et al., 2022) and studies on this topic struggle with the same methodological issues as studies on ecological impacts. ...
High-density grazing is a form of rangeland management aiming to strategically mimic the ways grasslands are utilized by grazers in natural situations. It aims to regenerate grasslands by improving soil and vegetation productivity and diversity. More recently, high-density grazing systems have been promoted as a key approach to mitigating climate change by increasing the amount of carbon sequestered in grassland soils. In this article, we describe the historical background of grazing and rangeland degradation in southern Africa, the principles of high-density grazing, and the problems it aims to address. We briefly discuss evidence of the potential benefits of high-density grazing, though we do not aim to provide an exhaustive review on this. We explore to what extent high-density grazing can be regarded as representative of grazing in natural ecosystems and whether the assumed link between nature and high-density grazing has been helpful in capitalizing on the potential merits of high-density grazing. While high-density grazing may represent a form of sustainable rangeland management, the main attractiveness to farmers likely relates to potential increases in livestock densities and associated productivity per unit area, as well as to potential management and social benefits. Learning from nature and inspiration by nature can play an important role in the development and communication of sustainable grazing management systems. However, it is questionable to what extent high-density grazing systems can be seen as more representative of natural ecosystems than other grazing management systems. The claimed ecological superiority of high-density grazing because of its association with nature has polarised and blurred the discussion on the potential merits of high-density grazing. Moreover, the supposed relationship between nature and high-density grazing may have led to an overselling of high-density grazing principles and an embracement of them by policy makers and development agencies without sufficient empirical basis.
... (2) Collect pre-program data on GAs. The evaluation team collected information on pre-429 program characteristics of each GA from interviews with TAs and AE staff, the 430 Namibian national census 37 , and the Namibian Atlas 38 . The latter has a geo-431 referenced database on climate, ecology, and livestock for the nation. ...
... Many research trials comparing rotational grazing to continuous grazing have failed to find a consistent and significant benefit to either forage yield or livestock production 36,37 . Trials were conducted on research stations where the experimental paddocks were small and research herds likewise small, sometimes only 3-4 head of cattle. ...
... Two limitations of previous rotational grazing studies are their limited spatial extent (small paddocks) and the use of fixed grazing schedules that ignored the human dimensions of adaptive decision making associated with multipaddock rotational grazing. Relationships between grazing systems and vegetation outcomes may operate differently in the context of adaptive management decision making at broad scales, where managers are often dealing with spatial and temporal variation in plant phenology, weather, plant community composition, and objectives ( Briske et al. 2011 ;Hawkins 2017 ;Hawkins et al. 2017 ;Teague and Barnes 2017 ). To address these limitations, we investigated tiller defoliation dynamics of western wheatgrass within the Collaborative Adaptive Rangeland Management experiment, located in the shortgrass steppe of eastern Colorado ( Wilmer et al. 2018 ;Fernández-Giménez et al. 2019 ;Augustine et al. 2020 ). ...
... Thus, there should be more potential for within-season regrazing (and more potential for tiller-scale benefits of rotation) in systems where two conditions are met: 1) forage quality is a stronger driver of foraging behavior than other factors like bite size, and 2) palatable plants are able to quickly regrow after defoliation. These conditions would be more common in mesic or fertile systems where overall biomass is higher and grazed plants have more resources available for regrowth after defoliation ( Maschinski and Whitham 1989 ;Heitschmidt et al. 1990 ;Hawkins 2017 ;Venter et al. 2020 ). However, several studies in mesic systems have failed to document strong effects of grazing system on levels of selectivity or regrazing rates at the plant scale ( Volesky 1994 ;Venter et al. 2019 ). ...
Frequent, severe defoliation reduces grass production and can alter plant species composition in grasslands. Multipaddock rotational grazing has been proposed as a grazing strategy that may reduce the frequency and intensity of defoliation on palatable grass plants without altering stocking rates. Previous studies evaluated this hypothesis using small, homogeneous paddocks and nonadaptive rotation schedules and found small and inconsistent differences between continuous and rotational grazing systems. Using a stakeholder-driven collaborative adaptive management (CAM) framework, we conducted the first ranch-scale experimental investigation into tiller defoliation patterns in the context of adaptive multipaddock rotational grazing. We monitored tiller defoliation frequency and intensity in 10 paired 130-ha pastures assigned to either a collaborative adaptive multipaddock rotational grazing treatment (CARM, one livestock herd) or a season-long continuous grazing treatment (traditional rangeland management [TRM]; 10 separate herds) in shortgrass steppe. Consistent with previous studies, we observed that frequencies of grazing and regrazing on a palatable, cool-season grass (western wheatgrass, Pascopyrum smithii) were much more sensitive to stocking rate than grazing system. Under moderate stocking rates used in both CARM and TRM treatments, roughly two-thirds of western wheatgrass tillers remained ungrazed annually, regardless of grazing system. Thus, season-long rest is present in season-long continuous and rotational grazing systems. Frequencies of tiller regrazing were low (5−15%) and similar between CARM and TRM treatments. Although defoliation patterns were similar between treatments at the whole-ranch scale, CARM enhanced spatial and temporal heterogeneity in defoliation frequencies among individual pastures. Pastures grazed earlier in the season or for longer experienced more defoliation. Managers implementing adaptive, multipaddock rotational grazing could use this heightened and predictable variability to strategically manage impacts of grazing on western wheatgrass at the individual pasture scale. The CAM model enabled our team to identify and directly address key stakeholder hypotheses and resulted in coproduction of management-relevant research.
... Several studies report the benefits of management intense rotational grazing, such as enhanced plant productivity, carbon sequestration, water infiltration, and habitat diversity (Davis et al., 2020;Döbert et al., 2021;Grenke, 2023;Johnson et al., 2022;McDonald et al., 2019b;Mosier et al., 2021;Stanley et al., 2018;Teague and Kreuter, 2020; but see, for example, Augustine et al., 2020), though its effects on plant composition and diversity have seldom been assessed (but see Grenke et al., 2022;Hawkins, 2017;McDonald et al., 2019b;Teague et al., 2011). This is surprising given that conservation and restoration of ecological processes underpin the broader concept of holistic management (Teague and Barnes, 2017). ...
Livestock grazing influences grassland biodiversity and ecosystem function. We report on the effects of adaptive multi-paddock (AMP) grazing (characterized by extended recovery periods between pulsed high animal density grazing events) on plant community composition and diversity across western Canada, compared to neighboring properties managed with conventional grazing (n-AMP). We also evaluated the influence of grazing practices, specifically stocking rate, cattle density, and variations in rest-to-grazing ratio at the start of the grazing season on plant community composition and diversity. We further explored the relationship between soil organic carbon (SOC) and plant diversity. Overall, AMP grazing, and specifically the use of high rest-to-grazing ratios early in the growing season, increased the proportion of non-native species. Native grasslands without prior cultivation had greater plant species richness, with fewer non-native species and containing phylogenetically more divergent plant communities, independent of grazing practices. The n-AMP pastures had higher functional trait dispersion, a pattern especially pronounced for tame (previously cultivated and seeded) pastures, and those with lower cattle stock densities (animals per unit area). Greater SOC was associated with communities higher in non-native plants, of lower species richness, and greater phylogenetic divergence, while no trend was identified for functional dispersion. Overall, AMP grazing did not increase plant species richness, functional diversity, or phylo-genetic diversity. Instead, pulsed rotational grazing, specifically using high stock densities and extended rest periods, facilitated non-native species prevalence and reduced functional diversity. However, non-native species and lower overall species richness may benefit SOC accumulation, illustrating the challenges associated with building biodiverse plant communities with a high capacity for climate change mitigation.
... Several studies report the benefits of management intense rotational grazing, such as enhanced plant productivity, carbon sequestration, water infiltration, and habitat diversity (Davis et al., 2020;Döbert et al., 2021;Grenke, 2023;Johnson et al., 2022;McDonald et al., 2019b;Mosier et al., 2021;Stanley et al., 2018;Teague and Kreuter, 2020; but see, for example, Augustine et al., 2020), though its effects on plant composition and diversity have seldom been assessed (but see Grenke et al., 2022;Hawkins, 2017;McDonald et al., 2019b;Teague et al., 2011). This is surprising given that conservation and restoration of ecological processes underpin the broader concept of holistic management (Teague and Barnes, 2017). ...
Livestock grazing influences grassland biodiversity and ecosystem function. We report on the effects of adaptive multi-paddock (AMP) grazing (characterized by extended recovery periods between pulsed high animal density grazing events) on plant community composition and diversity across western Canada, compared to neighboring properties managed with conventional grazing (n-AMP). We also evaluated the influence of grazing practices, specifically stocking rate, cattle density, and variations in rest-to-grazing ratio at the start of the grazing season on plant community composition and diversity. We further explored the relationship between soil organic carbon (SOC) and plant diversity. Overall, AMP grazing, and specifically the use of high rest-to-grazing ratios early in the growing season, increased the proportion of non-native species. Native grasslands without prior cultivation had greater plant species richness, with fewer non-native species and containing phylogenetically more divergent plant communities, independent of grazing practices. The n-AMP pastures had higher functional trait dispersion, a pattern especially pronounced for tame (previously cultivated and seeded) pastures, and those with lower cattle stock densities (animals per unit area). Greater SOC was associated with communities higher in non-native plants, of lower species richness, and greater phylogenetic divergence, while no trend was identified for functional dispersion. Overall, AMP grazing did not increase plant species richness, functional diversity, or phylogenetic diversity. Instead, pulsed rotational grazing, specifically using high stock densities and extended rest periods, facilitated non-native species prevalence and reduced functional diversity. However, non-native species and lower overall species richness may benefit SOC accumulation, illustrating the challenges associated with building biodiverse plant communities with a high capacity for climate change mitigation.
... However, studies from the journal (e.g. Tainton 1985;Hawkins 2017;Venter et al. 2019a) and elsewhere (e.g. Briske et al. 2008;Venter et al. 2019b;Augustine et al. 2020;) agree that, on balance, there is no difference for production when comparing intensive and season-long grazing. ...
... In addition, HDSD grazing led to improved rangeland conditions in terms of composition, cover, standing crop, and soil health compared to adjacent areas that did not fully implement it in Zimbabwe (Peel and Stalmans, 2018). However, Hawkins (2017) reported no difference in plant basal cover, plant biomass and animal gain responses between HDSD and ...
This paper investigates the impacts of policy and governance institutions on rangeland management practices in southern Africa. A scoping review was conducted, using literature from Web of Science, JSTOR, Scopus and Africa-wide bibliographic databases in the past three decades. The results revealed that several initiatives have been implemented in southern Africa to improve the condition of rangelands, including livestock destocking policies, grazing schemes, improved forage grasses, veld legume reinforcement, high-market beef value chains and agroforestry technology. However, the success of these initiatives has been limited due to a lack of meaningful participation in rangeland management. Moreover, the absence of responsive policies to support communal rangeland management in southern Africa has led to their transformation into unsustainable systems. Additionally, commercial interests often drive national-level policies and tend to disempower traditional institutions, causing conflicts and discord in rangeland management. Therefore, unrolling participatory bottom-up approaches will be essential for inclusive and sustainable rangeland management.
... While multipaddock grazing can be effective, its feasibility depends on regional conditions. However, Hawkins (Hawkins, 2017) concluded that only rangelands with higher precipitation have the resources to support MP grazing at a high stocking rate. Sustainable management of grasslands is essential for ensuring food and climate security. ...
Global per capita consumption of animal protein is set to rise, particularly in developing economies, leading to a dramatic increase in meat consumption from 133 million tons in 1980 to 452 million tons by 2050. Notably, 86% of this increase, or 279 million tons, is expected to occur in developing countries. The expansion of animal-based agricultural systems, which cover 45% of the Earth's land area, presents significant challenges. These systems contribute substantially to agricultural emissions, including greenhouse gases such as nitrous oxide (N2O) and methane (CH4), and account for 8% of global water usage. The livestock sector is largely comprised of resource-Review Article Godara et al.; Int. 84 constrained smallholders in developing nations. Environmental impacts arise from the lack of integration with other agricultural and forestry practices, disrupting the natural cycles of carbon, water, nitrogen, phosphorus, and sulfur. This disruption leads to increased emissions of N2O and CH4, water contamination, land degradation, and biodiversity loss. To address these challenges and support the United Nations' Sustainable Development Goals (SDGs) related to poverty reduction (SDG #1), hunger alleviation (SDG #2), clean water and sanitation (SDG #6), and climate action (SDG #13), it is essential to integrate livestock with crop and tree farming. Strategies to improve sustainability include incorporating pastures into crop rotations, using controlled grazing techniques, practicing agro-forestry such as alley cropping, and implementing systems like ley farming. Additional measures include precision feeding and protein matching to reduce enteric fermentation, repurposing emissions of CH4 and N2O, and effective manure management. Addressing greenhouse gas emissions through diverse approaches, reducing product wastage, minimizing antibiotic use, and restoring rangelands to enhance soil carbon storage are also critical for achieving sustainable livestock practices.
... Natural forest reserves are the biodiversity-rich habitats on the world because they not only host diversified vegetation but wildlife species as well (John et al. 2020;Kutnar et al. 2019;Lacerda and Kellermann 2019;Chen and Tang 2016;Hawkins 2017). These forest resources benefit human and animal lives by providing a variety of goods and services (Ghanbari et al. 2021). ...
Tree species diversity and distribution in forests, agroforests and other land uses have been continuously providing food and food-associated materials, medicinal, and livestock fodder, as well as multiple ecological services to human beings. However, unsustainable utilization of forest resources coupled with biotic and abiotic disturbances interrupt forest resources sustainability and ecological processes. A study was conducted in Abu Gadaf Natural Forest Reserve (AGNFR) in 2018 to assess the current status of tree species diversity and use, by surveying 554 sample circular plots (each having 35.7 m radius) with 0.5% sampling intensity distributed systematically throughout the reserve. We found a total of 32 tree species in the AGNFR that belonged to 16 families. The highest tree species frequency, occurrences and density recorded by Combretum hartmannianum followed by Lannea fruticosa and Anogeissus leiocarpus respectively. The highest Importance Value Index (IVI) was recorded by Combretum hartmannianum (51.28). The highest DBH of trees were reported in the range of 10–19.9 cm followed by 20–29.9 cm, additionally the Shannon diversity index and Simpson dominance index were 1.01 and 0.14, respectively and density was 48 tree/ha. Majority of the tree species was found unsustainably harvested affecting their regeneration potential. Different kinds of anthropogenic disturbances including forest fires were rampant in the reserve causing dwindling tree diversity. The study provides baseline information on tree species diversity, and distribution pattern for effective management and conservation of the forest reserve. A preservation action plan may be needed immediately to protect the vulnerable species, particularly those with high ecosystem service value.
... Thus, adaptive decision-making within the grazing season concerning the timing and sequence of livestock rotations among paddocks depends on ranchers matching animal nutritional demands with a myriad of factors, including forage phenology, composition, quantity, and quality in near-real time (Brunson and Burritt 2009). Scientific research on grazing management has largely avoided incorporating inter-and intra-annual adaptive decision-making by ranchers and land managers to enhance control in experimental designs (Briske et al. 2011a(Briske et al. , 2011bHawkins 2017). Adaptive decisions within the grazing season regarding when and where livestock graze individual paddocks can affect plant communities and the provision of multiple ecosystem services (O'Reagain and Turner 1992;Augustine et al. 2020;Derner et al. 2021). ...
Adaptive multi-paddock (AMP) grazing is hypothesised to improve livestock diet quality by allowing managers to move livestock among paddocks in a manner that tracks phenological variation in forage growth related to variation in plant community composition. We compared yearling steer (Bos taurus) dietary crude protein (CP), digestible organic matter (DOM), and diet composition on a ranch-scale (2600 ha, 10 pairs of 130 ha paddocks) experiment in shortgrass steppe for 6 years (2014-2019) in contrasting grazing treatments: Collaborative Adaptive Rangeland Management (CARM, a type of AMP with a stakeholder group making science-informed management decisions within the grazing season) and season-long, continuous grazing (TRM, traditional rangeland management). These grazing treatments had the same system-level stocking rate annually but differed in stocking density, with CARM being 10-fold higher than TRM because of all steers in the CARM treatment being in a single herd. Mean grazing-season dietary CP was consistently 13-28% higher in TRM than CARM; in contrast, DOM in TRM was similar to CARM or only slightly higher (2.5%). Differences in diet quality between CARM and TRM grazing strategies were largest early in the grazing season, with CP being 14-36% higher for TRM compared to CARM steers during the first 4 weeks; these diet-quality differences between treatments disappeared towards the end of the grazing season. Implementing AMP on the basis of a diverse stakeholder group's experiential knowledge about plant communities, soils, and ecological sites did alter within-grazing season plant functional group contributions to steer diets. Although we implemented adaptive decision-making within the grazing season, which allowed CARM steers to track the seasonal phenology of C 3 versus C 4 grasses as steers rotated among paddocks varying in plant community composition, these adaptive movements did not offset the detrimental effects on diet quality associated with grazing in a herd with 10-fold higher stocking density. Managers applying AMP in semiarid rangelands should be cognisant that high stocking density can be associated with lower diet quality early in the growing season, which can compromise livestock gain responses.
... The role of periodic, full season rests is not often adequately described in various meta-analyses and evaluations of grazing systems, probably because most management focuses on grazer movements within a single grazing season, rather than across years (Barnes, 1992;O'Reagain and Turner, 1992;Briske et al., 2008;Teague et al., 2013;Hawkins, 2017;McDonald et al., 2019). Evaluating the impacts of periodic full season rests on grassland ecosystem health and livestock performance logically requires a multiyear study, which might explain the lack of clear differentiation between the outcomes of experiments examining continuous and rotational grazing. ...
... Hoof action of livestock is suggested to break hard setting soil crusts, thus facilitating nutrient cycling, microbial activity, and carbon sequestration, but this has not been adequately tested and needs careful attention where biological crusts are dominant (Hawkins, 2017). This phenomenon also varies between land types and may be less relevant in Australia where there were no native hard-hoofed animals prior to colonisation (Garnett et al., 2017). ...
The livestock industry accounts for a considerable proportion of agricultural greenhouse gas emissions, and in response, the Australian red meat industry has committed to an aspirational target of net-zero emissions by 2030. Increasing soil carbon storage in grazing lands has been identified as one method to help achieve this, while also potentially improving production and provision of other ecosystem services. This review examined the effects of grazing management on soil carbon and factors that drive soil carbon sequestration in Australia. A systematic literature search and meta-analysis was used to compare effects of stocking intensity (stocking rate or utilisation) and stocking method (i.e, continuous, rotational or seasonal grazing systems) on soil organic carbon, pasture herbage mass, plant growth and ground cover. Impacts on below ground biomass, soil nitrogen and soil structure are also discussed.
Overall, no significant impact of stocking intensity or method on soil carbon sequestration in Australia was found, although lower stocking intensity and incorporating periods of rest into grazing systems (rotational grazing) had positive effects on herbage mass and ground cover compared with higher stocking intensity or continuous grazing. Minimal impact of grazing management on pasture growth rate and below-ground biomass has been reported in Australia. However, these factors improved with grazing intensity or rotational grazing in some circumstances.
While there is a lack of evidence in Australia that grazing management directly increases soil carbon, this meta-analysis indicated that grazing management practices have potential to benefit the drivers of soil carbon sequestration by increasing above and below-ground plant production, maintaining a higher residual biomass, and promoting productive perennial pasture species. Specific recommendations for future research and management are provided in the paper.
... In their meta-analysis conducted under a wide range of environmental conditions worldwide, Byrnes et al. (2018) found that rotational grazing could improve soil organic carbon and bulk density over continuous grazing strategies, which could have eventual benefits for pasture production. On the other hand, the meta-analyses conducted by Briske et al. (2008) and Hawkins (2017) reported no evidence that AMP grazing has an enhanced effect on vegetation characteristics compared to less rotational practices. Experimental limitations (e.g., spatial limitations, short-term nature, and inflexible grazing treatments) have prevented researchers from adequately accounting for the spatial heterogeneity of vegetation in AMP systems (Teague et al., 2013). ...
Adaptive Multi-Paddock (AMP) is a grazing system which combines intensive, rapid grazing livestock rotation with relatively short grazing periods and long recovery time after grazing. The study assesses, under Mediterranean silvopastoral systems, changes in pasture phenology and spatial variability after adopting the AMP under contrasting land cover (Wooded Grassland vs Grassland ) with a remote sensing approach based on the time-series analysis of Normalized Difference Vegetation Index (NDVI) from remote sensing through Landsat satellite. The study revealed an overall positive effect of rotational grazing on pasture phenology and NDVI spatial variability. The AMP adoption resulted in higher estimated values of NDVI at the beginning (under grassland land cover), the end, and the peak of the growing season, while no differences were observed in parameters estimating the length of the growing season. The spatial variability of NDVI was always lower under AMP than in continuously grazed areas, except in the early stages of the growing season under grassland land cover. The results suggested that in a relatively short period (4-5 years), the AMP grazing system can represent a strategy to improve forage availability and exploitation by grazing animals under low stocking rates in extensively managed Mediterranean silvopastoral systems.
... A 45-day grazing (that is, animals graze once in 45 days) frequency was considered for winter because subtropical grass growth is very low in this season (Cosgrove et al., 2003;Meat and Livestock Australia, 2021;Shelton, 2021). Also, a continuous stocking strategy was considered since some farms practice this method (Hawkins, 2017;Wang et al., 2016). In a continuous stocking strategy, grazing is carried out daily to return biomass to the residual biomass adopted. ...
This study aimed to model pasture production for sub-tropical grass under different photovoltaic installations and assess the effects of different grazing methods on sub-tropical pasture productivity in Australia.
... Controversially, a study performed in Colombia under short duration grazing systems indicated higher pasture and animal productivity with further positive impacts on soil quality [41]. In another meta-analysis comparing the performance of holistic planned grazing versus seasonally continuous grazing at moderate stocking rates in different countries and ecosystems, no difference was found regarding plant and animal productivity [210], which can be a result of erroneous selection of grazing factors such as low stocking rates, long occupation periods and/or inadequate recovery period for the pasture. In the Piedmont region of Georgia, United States however, a continuous grazing system approach was more detrimental for soil health and increased runoff compared to strategic grazing [211]. ...
Grasslands and ecosystem services are under threat due to common practices adopted by modern livestock farming systems. Design theory has been an alternative to promote changes and develop more sustainable strategies that allow pastoral livestock production systems to evolve continually within grasslands by enhancing their health and enabling the continuous delivery of multiple ecosystem services. To create a design framework to design alternative and more sustainable pastoral livestock production systems, a better comprehension of grassland complexity and dynamism for a diagnostic assessment of its health is needed, from which the systems thinking theory could be an important approach. By using systems thinking theory, the key components of grasslands—soil, plant, ruminant—can be reviewed and better understood from a holistic perspective. The description of soil, plant and ruminant individually is already complex itself, so understanding these components, their interactions, their response to grazing management and herbivory and how they contribute to grassland health under different climatic and topographic conditions is paramount to designing more sustainable pastoral livestock production systems. Therefore, by taking a systems thinking approach, we aim to review the literature to better understand the role of soil, plant, and ruminant on grassland health to build a design framework to diagnose and enhance grassland health under pastoral livestock production systems.
... The studies showed that there was a small portion of rangelands has the capacity to sustain HPG. There is also attention to investigate how the holistic planned grazing (HPG) affects socio-ecological constitution of rangelands (Hawkins, 2017). Rochea et al. (2015) reported that Over 93% of all rotational grazer defendants in California characterized as using extensive intra-growing season rotation with moderate grazing period durations, livestock densities, and growing season rest periods. ...
... The kind of grazing that results from HM is typically called Holistic Planned Grazing: high-intensity and short-duration, and requires paddock subdivision, moveable water points and other significant changes to infrastructure and farming paradigm (Gosnell, Gill, and Voyer 2019). Savory's (2013) TED talk on HM inspired new debate in academe and the public sphere about whether 'it works' (Garnett et al. 2017;Hawkins 2017;Nordborg and Röös 2016), and whether what is really needed in the face of climate change is more livestock (Monbiot 2014, August 4, 2014. In recent decades, advocates of HM and similar approaches have largely bypassed public debate and the academic literature, instead working directly with farmers through institutes and training. ...
First 50 downloads free at https://www.tandfonline.com/eprint/MP8AQ2REZHKZI4U8KU7J/full?target=10.1080/21683565.2022.2107597 ** Adaptive multi-paddock (AMP) grazing practices have been debated based on production, environmental and workload impacts, but farmer wellbeing is only beginning to be explored. A panel-based online survey of 200 Canadian beef producers was undertaken in early 2020 with a descriptive aim to explore the uptake, management, mindsets, and wellbeing implications associated with AMP grazing. AMP practices were more common than expected (29%) as well as distinct in grazing regime, featuring fast rotation, and long rests. AMP ranchers reported high physical wellbeing, as well as systems thinking, nontraditional values, a priority for enjoying life and tendency to use a wide range of modes to learn about grazing. Other dimensions of wellbeing, environmental motivations, and gender dimensions suggested by smaller-n studies were not associated with AMP grazing in this work. These insights are important as the federal government begins to promote AMP grazing and its variants as strategies to combat climate change. More nuanced understanding of adaptive grazing and its trajectory would be possible via consistent, longitudinal surveys with improved operationalization of well-being concepts, more detailed exploration of educational background , inclusion of religious beliefs, and elucidation of management characteristics beyond grazing regime variables.
... It has also been advocated that to obtain the greatest productivity benefit from RG, paddock rest periods need to be varied according to the season to account for changes in forage growth rate (Voisin, 1959), although many studies in our dataset applied the same grazing and rest periods across the whole grazing season. The increase in DM production with lengthened rest period, and the implication from Fig. 3 that livestock growth rates can be maintained as stocking density increases if rest periods are sufficiently long, appears to suggest that RG can support higher stocking densities than continuous grazing, as has been found in Australia (Badgery and Michalk, 2017) although disputed in a rangeland context (Hacker, 1993;Briske et al., 2008;Hawkins, 2017). In our analysis, however, rest period and stocking density are non-independent. ...
Reducing greenhouse gas emissions associated with ruminant livestock production is important for climate change mitigation. Regenerative Agriculture (RA) practices are increasingly promoted to improve forage production and livestock performance in temperate livestock systems. These practices include i) rotational grazing (RG) of livestock around multiple subunits of pasture to achieve ungrazed periods of ‘rest’, and ii) herbal leys (HL), where perennial forbs such as chicory, lucerne and trefoils are included as components in multi-species swards. While there are plausible mechanisms for adoption of these practices to improve agricultural productivity, quantitative syntheses of their impacts are required. Here, we conduct a systematic review and meta-analysis of the effects of RG and HL practices on herbage dry matter (DM) production, animal daily liveweight gain (DLWG), and sheep wool growth in temperate oceanic regions. We use quantitative predictors in our Bayesian hierarchical models to investigate the role of rest period and stocking density in RG systems, and specific plant traits and sward diversity in HL. We found that herbage DM increased by 0.31 t.ha⁻¹ over a growing season as the proportion of rest in an RG grazing system increased from 0 to 1. Stocking density significantly moderated the effect of rest period on sheep and cattle DLWG; at higher stocking densities, longer rest periods were required to maintain livestock growth rates. In HL studies, herbage DM yielded 1.63 t.ha⁻¹ more per metre of increased sward root depth and a sward entirely comprised of legumes yielded 2.20 t.ha⁻¹ more than when no legumes were present. Sheep DLWG increased by 3.50 g.day⁻¹ per unit increase in leaf nitrogen concentration (mg.g⁻¹), but we could not determine an effect of leaf condensed tannin content on animal performance. Although there remain differences between the RG and HL study treatments meta-analysed here and RA in practice, our results provide empirical support for some of the mechanisms attributed to increased pasture and livestock productivity following adoption of selected RA grazing practices.
... Studies more commonly report on mob grazing as a means of 1) controlling undesirable shrubs ( Bailey and Brown 2011 ;Mesléard et al. 2017 ) and exotic species ( James et al. 2017 ), 2) manipulating proportions of C 3 and C 4 plants in a management unit ( Hickman et al. 2004 ), and 3) improving distribution of grazing and evenness of utilization of vegetation cover ( Barnes et al. 2008 ;Norton et al. 2013 ;Reed et al. 2019 ). Animal performance in a mob grazing system is commonly reported to be less than on less intensively managed pastures (simple rotationally and continuously stocked pastures) ( Hawkins 2017 ;Tracy and Bauer 2019 ;Augustine et al. 2020 ), likely because of extremely high grazing pressure and consumption of lower-quality forage ( Tracy and Bauer 2019 ). ...
Management-intensive grazing, which is proposed to increase forage and animal productivity and maintain soil integrity and biodiversity, is seen as an alternative to meet 21st century agricultural and environmental challenges. The purpose of this study was to test the hypothesis that high levels of trampling of standing vegetation associated with mob grazing (a.k.a., ultrahigh stocking density) leads to increased plant diversity and productivity. A long-term experiment was established on a subirrigated meadow in the Nebraska Sandhills as a complete block design comparing three grazing treatments applied annually during the growing season for 8 consecutive yr (2010−2017): 120-pasture rotation with one grazing cycle (mob; 225 000 kg live weight ha⁻¹), four-pasture rotation with one grazing cycle (4PR1; 7 000 kg live weight ha⁻¹), and four-pasture rotation with two grazing cycles (4PR2; 5 000 kg live weight ha⁻¹). All treatments were set at a moderate stocking rate (7.4 animal unit months ha⁻¹) using yearling steers. Percentage trampling, plant production, species composition, and steer weight gain were estimated annually. We applied linear mixed-effect models to account for year and treatment effect on the response variables. Percentage trampling on mob pastures ranged from 40% to 55% over the 8 yr of the study, nearly double that of the 4PR1 and 4PR2 pastures. We observed that mob grazing had no overall effect on plant species composition, aboveground production, and root growth relative to low stocking densities. Average daily gain of steers in the mob pastures was less than gain of steers in 4PR2 pastures in all years, with intermediate weight gains for the 4PR1 steers. Overall, stocking density did not appear to be a driver of plant composition and productivity in rotationally grazed pastures on subirrigated meadows in the Nebraska Sandhills.
... Grazing practices that incorporate periods of planned rest are commonly promoted to avoid environmental degradation and improve productivity (Norton 1998a;Teague et al. 2008) but considerable debate exists around the benefits, or otherwise, of these grazing management systems (Briske et al. 2008;Teague et al. 2013). Previous reviews have generally concluded that there is little difference in outcomes for animal production (i.e., weight gain, production per unit area, reproductive success) or rangeland sustainability (i.e., maintenance of biomass or ground cover) between contrasting management systems (Gammon 1978;O'Reagain and Turner 1992;Holechek et al. 2000;Briske et al. 2008;Hawkins et al. 2017;di Virgilio et al. 2019). Yet, recent meta analyses indicate that alternative grazing systems that incorporate periods of rest, compared with continuously grazed or ungrazed areas, have the potential to achieve multiple objectives (e.g. ...
With increasing pressure on grazing lands throughout the world, there is a growing need to balance sustainable management of livestock to meet food production and environmental impacts. Grazing management practices that incorporate periods of planned rest between grazing events (RG) may achieve both ecological and production goals simultaneously. We conducted a systematic review of global literature that compared ecological and production outcomes of RG systems with either continuously grazed (CG) or ungrazed (UG) areas. In addition, we evaluated the extent to which ecological and livestock production outcomes have been assessed simultaneously in these studies and identified future research needs. A large proportion of the literature reported no difference (neutral response) between the different management systems. However, where differences did occur, the response of biodiversity, land condition and livestock production metrics was more often positive under RG than CG. When RG was compared to UG areas, differences were predominantly positive for plant biodiversity metrics, but negative for invertebrate biodiversity, ground cover and plant biomass. Only a small proportion of studies considered the effect of RG on both ecological and production outcomes simultaneously. An understanding of both ecological and production trade-offs associated with different grazing management strategies is essential to make informed decisions about best-management practices for joint production and ecological outcomes across the world's grazing lands.
... Rangelands are the most extensive land cover type on earth and provide numerous ecosystem services, such as biodiversity, water, carbon sequestration, food, fiber, fuel, and cultural values ( Briske,Figure 1. Simplified diagram of the beef cattle weight gain process in APEX. ( Briske et al. 2008( Briske et al. , 2011Hawkins 2017 ;Harmel et al. 2021 ). For example, Teague et al. (2013) concluded that several factors influence the potential benefits of rotational grazing, including 1) providing for adequate plant recovery, 2) modifying livestock distribution and grazing intensity, and 3) regulating livestock nutrition and feeding behavior. ...
Rotational grazing studies have produced mixed results related to animal performance (weight gain), which has contributed to producer uncertainty regarding grazing management decisions. To enhance decision-support for producers, we improved algorithms in the Agricultural Policy/Environmental eXtender (APEX) model to better represent cattle weight gain in real-world rangeland conditions under two grazing management strategies. Simulated weight gain and related forage effects were evaluated with experimental data from 2014 to 2018 under two grazing strategies. The traditional rangeland management strategy used continuous season-long grazing stocked at a moderate level. The collaborative adaptive rangeland management strategy employed grazing with one large herd rotated using a sequence developed by a stakeholder group with movement between pastures driven by predetermined decision triggers. For each grazing strategy, yearling steers grazed from mid-May to October on ten 130-ha pastures. With the APEX modifications, daily weight gain was adequately simulated for both continuous (traditional rangeland management) grazing and management intensive rotational (collaborative adaptive rangeland management) grazing. Dry matter intake, total digestible nutrients, and temporal distribution of dry matter intake were the primary influencers of cattle performance (weight gain). Once shown to be accurate, we used APEX to evaluate several management alternatives (i.e., stocking rate, rotation interval, and rotation decision criteria) to showcase its decision support capabilities. These important enhancements increase the utility of APEX in semiarid environments, such as the western Great Plains, in providing science-based rangeland decision support to ranchers, agency land managers, and policy makers.
... Claims about the ubiquitous superiority of ReGM are controversial, divisive, and strongly contested (see Briske et al., 2013;Sherren and Kent, 2019;Gosnell et al., 2020), spurring numerous studies, reviews (Skovlin, 1987;Holechek et al., 2000;Briske et al., 2008;Nordborg, 2016;Hawkins et al., 2022) and a meta-analysis (Hawkins, 2017). These studies and syntheses have revealed varied ecosystem and agronomic responses to ReGM with little compelling empirical evidence that ReGM will improve grass and animal production and vegetation condition wherever it is applied. ...
Regenerative grazing management (ReGM) seeks to mimic natural grazing dynamics to restore degraded soils and the ecological processes underpinning sustainable livestock production while enhancing biodiversity. Regenerative grazing, including holistic planned grazing and related methods, is an adaptive, rotational stocking approach in which dense livestock herds are rotated rapidly through multiple paddocks in short bouts of grazing to defoliate plants evenly and infrequently, interspersed with long recovery periods to boost regrowth. The concentrated “hoof action” of herds in ReGM is regarded vital for regenerating soils and ecosystem services. Evidence (from 58 studies) that ReGM benefits biodiversity is reviewed. Soils enriched by ReGM have increased microbial bioactivity, higher fungal:bacteria biomass, greater functional diversity, and richer microarthropods and macrofauna communities. Vegetation responds inconsistently, with increased, neutral, or decreased total plant diversity, richness of forage grasses and invasive species under ReGM: grasses tend to be favored but shrubs and forbs can be depleted by the mechanical action of hooves. Trampling also reduces numerous arthropods by altering vegetation structure, but creates favorable habitat and food for a few taxa, such as dung beetles. Similarly, grazing-induced structural changes benefit some birds (for foraging, nest sites) while heavy stocking during winter and droughts reduces food for seedeaters and songbirds. With herding and no fences, wildlife (herbivores and predators) thrives on nutritious regrowth while having access to large undisturbed areas. It is concluded that ReGM does not universally promote biodiversity but can be adapted to provide greater landscape habitat heterogeneity suitable to a wider range of biota.
... Claims about the ubiquitous superiority of ReGM are controversial, divisive, and strongly contested (see Briske et al., 2013;Sherren and Kent, 2019;Gosnell et al., 2020), spurring numerous studies, reviews (Skovlin, 1987;Holechek et al., 2000;Briske et al., 2008;Nordborg, 2016;Hawkins et al., 2022) and a meta-analysis (Hawkins, 2017). These studies and syntheses have revealed varied ecosystem and agronomic responses to ReGM with little compelling empirical evidence that ReGM will improve grass and animal production and vegetation condition wherever it is applied. ...
Regenerative grazing management (ReGM) seeks to mimic natural grazing dynamics to restore degraded soils and the ecological processes underpinning sustainable livestock production while enhancing biodiversity. Regenerative grazing, including holistic planned grazing and related methods, is an adaptive, rotational stocking approach in which dense livestock herds are rotated rapidly through multiple paddocks in short bouts of grazing to defoliate plants evenly and infrequently, interspersed with long recovery periods to boost regrowth. The concentrated 'hoof action' of herds in ReGM is regarded vital for regenerating soils and ecosystem services. Evidence (from 58 studies) that ReGM benefits biodiversity is reviewed. Soils enriched by ReGM have increased microbial bioactivity, higher fungal:bacteria biomass, greater functional diversity, and richer microarthropods and macrofauna communities. Vegetation responds inconsistently, with increased, neutral, or decreased total plant diversity, richness of forage grasses and invasive species under ReGM: grasses tend to be favoured but shrubs and forbs can be depleted by the mechanical action of hooves. Trampling also reduces numerous arthropods by altering vegetation structure, but creates favourable habitat and food for a few taxa, such as dung beetles. Similarly, grazing-induced structural changes benefit some birds (for foraging, nest sites) while heavy stocking during winter and droughts reduces food for seedeaters and songbirds. With herding and no fences, wildlife (herbivores and predators) thrives on nutritious regrowth while having access to large undisturbed areas. It is concluded that ReGM does not universally promote biodiversity but can be adapted to provide greater landscape habitat heterogeneity suitable to a wider range of biota.
https://www.frontiersin.org/articles/10.3389/fevo.2021.816374/full
... Natural reserved forests are biodiversity-rich habitats on the globe because they host diversified flora and fauna species ( John et al., 2020 ;Kutnar et al., 2019 ;Lacerda and Kellermann, 2019 ;Chen and Tang, 2016 ;Hawkins, 2017 ). Forests and their trees support human and animal lives by the provision of various products and services ( Beltrán-Rodríguez et al., 2021 ;Ghanbari et al., 2021 ;Mohammed et al., 2021 ). ...
Forests and forest trees have continuously been supporting human beings through the provision of food and food-associated materials, fodder and foraging sites for their livestock, and medicinal materials, as well as multiple ecological services. However, unbalanced utilization of these resources and the biotic and abiotic disturbances interrupt their sustainability and ecological functions. We studied the tree population structure, diversity, and regeneration status of tree species in the Abu Gadaf Natural Reserved Forest in 46 sample plots of 20 m x 50 m (1000 m²) distributed systematically throughout the reserve over a year. The study findings showed that highland sites have higher tree species richness (47 species) compared to lowland sites (31 species) and the highest contributors are Combretaceae (21.3%) and Fabaceae (19.2%) families. Moreover, seedlings in highland sites are twice that of lowlands, with a significant difference between the two sites (F1,46 = 138.4, p < 0.001). The same trend has been observed for saplings and adult trees (F1,46 = 143.2, p < 0.01; F1,46 = 126.7, p < 0.01, respectively). Likewise, all dendrometric parameters and diversity indices demonstrated significant differences between the sites across the reserve with lower values in the lowland sites and vigorous regeneration in the highland sites (T = 33.7, P < 0.001; T = 22.3, P = 0.001; T = 27.9, P = 0.042, respectively). The study concludes that over browsing by livestock and intensive illegal tree logging in the lowland sites have severely affected the tree population composition, which might consequently disturb the regeneration process and seedlings recruitment. A conservation action plan is urgently needed to protect vulnerable species, especially those with low importance value index.
... Rangelands are the most extensive land cover type on earth and provide numerous ecosystem services, such as biodiversity, water, carbon sequestration, food, fiber, fuel, and cultural values ( Briske,Figure 1. Simplified diagram of the beef cattle weight gain process in APEX. ( Briske et al. 2008( Briske et al. , 2011Hawkins 2017 ;Harmel et al. 2021 ). For example, Teague et al. (2013) concluded that several factors influence the potential benefits of rotational grazing, including 1) providing for adequate plant recovery, 2) modifying livestock distribution and grazing intensity, and 3) regulating livestock nutrition and feeding behavior. ...
CONTEXT
Simulation tools are increasingly used to inform grazing management decisions by assessing livestock performance, as well as environmental and economic impacts. Ability to represent the grazing of multiple pastures (i.e., paddocks) that differ in soil, hydrology, vegetation, and management is critical for reliable grazing management decision support.
OBJECTIVE
The main objectives of this study were to: 1) modify APEX (Agricultural Policy/Environmental eXtender) for sub-daily grazing, cow-calf weight gain, and supplemental hay, and 2) evaluate the APEX modifications in terms of simulating biomass, calf weight gain, economic impacts of alternative cow-calf grazing management strategies.
METHODS
APEX was modified to enhance its ability to simulate alternative grazing management strategies by including sub-daily grazing among multiple paddocks, supplemental hay estimation, and optional simulation of cow-calf weight gain based either on energy or total digestible nutrients (TDN). Simulation results were evaluated against a 5-year experimental data set from Central Texas comparing multi-paddock rotational grazing and conventional continuous grazing.
RESULTS AND CONCLUSION
The modified APEX model adequately simulated the responses of vegetation biomass (coefficient of determination, R² = 0.60–0.70), hay consumption (R² = 0.94–0.95), calf weaning weight (R² = 0.52–0.65), costs (R² = 0.98), and profits (R² = 0.89) to the two grazing treatments across years. Simulations with the energy-based weight gain algorithm showed more pronounced effects on above-ground biomass, whereas the TDN-based algorithm had a more pronounced weight gain response to forage intake and hay quality. No significant differences (p > 0.05) in biomass and calf weaning weight were observed between treatments across the years for measured data and for energy-based APEX simulation; however, the TDN-based algorithm simulated lower calf weaning weight in multi-paddock rotational grazing than in continuous grazing. Measured and simulated data also showed similar profits between the two grazing treatments, but total cost and gross return per ha were greater for continuous grazing.
SIGNIFICANCE
The model enhancements for sub-daily grazing, cow-calf weight gain, and supplemental hay improved the potential utility of APEX for assessing environmental and economic impacts of alternative grazing strategies at ranch scale.
... Similarly, in the western rangelands of North America, rest-rotational, deferred rotational, seasonal suitability, best pasture, short duration, season-long, and continuous grazing or foraging systems are practised (Frost and Mosely, 2020). Among these systems in extensive environments, evidence exists that rotational or cell grazing is no more productive and is less profitable than set stocking for beef production (Briske et al., 2008;Hall et al., 2014Hall et al., , 2016Hawkins, 2017). ...
Beef is a high-quality source of protein that also can provide highly desirable eating experiences, and demand is increasing globally. Sustainability of beef industries requires high on-farm efficiency and productivity, and efficient value-chains that reward achievement of target-market specifications. These factors also contribute to reduced environmental and animal welfare impacts necessary for provenance and social licence to operate. This review provides an overview of beef industries, beef production, and beef production systems globally, including more productive and efficient industries, systems and practices. Extensive beef production systems typically include pasture-based cow-calf and stocker-backgrounding or grow-out systems, and pasture or feedlot finishing. Cattle in pasture-based systems are subject to high levels of environmental variation to which specific genotypes are better suited. Strategic nutritional supplementation can be provided within these systems to overcome deficiencies in the amount and quality of pasture- or forage-based feed for the breeding herd and for younger offspring prior to a finishing period. More intensive systems can maintain more control over nutrition and the environment and are more typically used for beef and veal from dairy breeds, crosses between beef and dairy breeds, and during finishing of beef cattle to assure product quality and specifications. Cull cows and heifers from beef seedstock and cow-calf operations and dairy enterprises that are mostly sent directly to abattoirs are also important in beef production. Beef production systems that use beef breeds should target appropriate genotypes and high productivity relative to maintenance for the breeding herd and for growing and finishing cattle. This maximizes income and limits input costs particularly feed costs which may be 60% or more of production costs. Digital and other technologies that enable rapid capture and use of environmental and cattle performance data, even within extensive systems, should enhance beef industry productivity, efficiency, animal welfare and sustainability.
... Among other factors, climate heterogeneity could affect the relative benefits of RG vs CG. For example, Hawkins (2017) found that most studies in areas with less than 400 mm precipitation showed negative or no significant RG benefits on plant basal cover and they concluded that RG is more suitable in areas with moderate or high precipitation. Given that the average annual precipitation in our study area is 626 mm with only 4.23% of the respondents having less than 400 mm rainfall, most of our survey respondents are located in moderate precipitation areas. ...
Experimental findings on rotational grazing (RG) trials have generally differed from producer observations of RG outcomes on commercial scale ranches. Factors such as small plot size, short duration trials and relatively rigid grazing management that lacks responsiveness to the dynamic and complex social-ecological systems in grazing trials could all contribute to this disparity in outcomes. These differences call for a better understanding of producer perceptions of RG benefits. To fill this knowledge gap, we surveyed 4500 producers from the Northern and Southern Great Plains of the USA. Among the 875 respondents, 40.5% reported that they used continuous grazing (CG), 52.7% implemented RG management in an extensive manner, while 6.8% adopted management intensive grazing. Compared with CG users, adopters of RG in its extensive and intensive form reported an average annual increase of grazing season by 7.6 and 39.3 days, respectively. When controlling for producer demographics, ranch management goals and other rancher characteristics, we found soil and climate heterogeneity significantly affected the perceived relative benefits of RG vs CG strategies. Therefore, instead of focusing on whether RG outperforms CG per se , future research could focus on comparison of RG benefits under different management intensity levels and identifying soil and climate conditions where RG benefits are more noticeable.
... Interpreted at the time as irrational conservatism, pastoral reluctance to adopt rotational grazing makes sense in terms of the most systematic metanalysis yet conducted of the performance of these systems: "[S]ubjected to as rigorous a testing regime as any hypothesis in the rangeland profession, " rotational grazing systems have been found to "convey few, if any, consistent benefits" and it is likely that ". . . a continuation of costly grazing experiments adhering to conventional research protocols will yield little additional information" (Briske et al., 2008, p. 11; see also Heady, 1961;O'Reagain and Turner, 1992;Holechek et al., 2001;Bailey and Brown, 2011;Hawkins, 2017). Despite the decades of negative or mixed results in the works cited above, the debate about the efficacy of rotational systems in semi-arid rangelands grinds on without resolution (Teague et al., 2013;Briske et al., 2014). ...
This essay examines three central components of extensive livestock production—herd composition, grazing/pasture management, and rangeland tenure. In all of these areas, fenced, and open-range forms of migratory pastoralism face a number of shared problems. Set aside the presumption that either one of these systems is technically or institutionally more advanced than the other, and it turns out that each has lessons for the other. 1. For a variety of reasons, including climate change, we can look forward to a future world with less grass, which presents a challenge for livestock producers reliant on grass feeding livestock. With little delay and minimal scientific support, East African pastoralists are already adjusting to a new woody world by diversifying the species composition of their herds to include more browsers—camels and goats. There is a potential lesson here for commercial ranchers who have traded the stability of mixed herds for the profitability of keeping sheep or cattle alone. 2. Migratory rangeland systems distribute livestock very differently than fenced, rotational systems of livestock, and pasture management. Whereas, migratory herds exploit environmental heterogeneity, fenced ranching attempts to suppress it. Emerging archaeological evidence is demonstrating that pastoralists have amplified rangeland heterogeneity for millennia; ecological research shows that this heterogeneity sustains both plant and wildlife biodiversity at the landscape scale; and new approaches to ranch management are appropriating aspects of migratory herding for use on fenced ranches. A rapprochement between the environmental sciences, ranching, and open-range migratory pastoralism has occurred and merits wider policy recognition. 3. In contemporary Africa, indigenous tenure regimes that sustain open rangelands are eroding under pressure from market penetration and state encapsulation. At the same time in the American West, there are emerging novel land tenure instruments that replicate some of the most important functional characteristics of tenure arrangements in pastoral Africa. After many false starts, it appears that some aspects of American ranching do provide an appropriate model for the preservation of the open-range migratory systems that they were once supposed to supplant. “Development” policy needs to reflect upon this inversion of roles and its implications for accommodating diversity.
... Rangeland productivity depends on the grazing management of biotic (browsers, large and small stock) and abiotic (climate and lithology) components of the Drakensberg farming system (Hawkins 2017). Rangeland management in southern Africa comprises rotational grazing, zero grazing, or a combination of both, monitoring stocking rate, camp size, and recovery periods. ...
... Rangeland productivity depends on the grazing management of biotic (browsers, large and small stock) and abiotic (climate and lithology) components of the Drakensberg farming system (Hawkins 2017). Rangeland management in southern Africa comprises rotational grazing, zero grazing, or a combination of both, monitoring stocking rate, camp size, and recovery periods. ...
Achieving sustainable food security is a critical goal for smallholder farmers in mountainous regions around the world. In the 40,000 km2 Maloti–Drakensberg mountains (South Africa and Lesotho), one of the important mountain ranges of southern Africa, farmers are directly dependent on natural resources. Natural resource management is currently unsustainable, driving landscape degradation and entrenching poverty cycles. Through a comprehensive literature review, we explore the current status of knowledge, opportunities, and agriculture-dependent natural resource sustainability in the Maloti–Drakensberg, and outline the priorities for future research in mountain agriculture in southern Africa. The Maloti–Drakensberg has diverse land tenure systems and climatic heterogeneity that together determine farming practices. Agropastoralism is the predominant agricultural practice, occupying 79% of the land, because of the natural grass-dominated vegetation. Despite decades of concern, the sustainable management of communal rangeland remains elusive. Arable cropping is practiced on 12% of the land at subsistence levels, while game farming contributes a small amount to local revenues. A multipronged research approach is needed to understand the complex social–ecological issues around soil degradation and sustainable utilization of the limited agricultural natural resources base. Innovative and adaptive strategies that take into account local and indigenous knowledge, mitigate soil degradation, and enhance water and rangeland conservation are needed to promote sustainable food production in the Maloti–Drakensberg.
... 46 Alan Savory and other proponents and practitioners have claimed astonishing results in terms of reversing desertification and revegetating deteriorated rangelands as pictured above. Scientists have mostly failed to reproduce and therefore validate these results, a meta-analysis could find no difference between Holistically Planned Grazing and rotational grazing in plant biomass and weight gained by livestock(Hawkins 2017). However, most research on the topic has been criticised for their small scale, non-adaptiveness and short period because they have been "designed and conducted in46 Album with various photographs: http://www.holisticresults.com.au/your-resources/photo-albums ...
Humanity is confronted with a number of pressing and interrelated unsustainability crises including the stark reliance on dwindling finite resources, accelerating climate change, alarming rates of biodiversity loss, and degradation of natural habitats. Industrial agriculture as a specific regime of input intensive, mechanized, large-scale, and uniform food production is one main driver and therefore itself unsustainable. The public, policymakers, and farmers themselves increasingly worry about the decline in soil fertility, loss of topsoil and farming systems not resilient enough at the sight of a warming climate, more erratic rainfall, and predicted increase in drought events.
Regenerative Agriculture is one recent contribution to the discourse on a more sustainable agriculture. It started to emerge as a distinct concept a few years ago and puts a strong focus on building soil organic matter in the context of carbon sequestration and climate change mitigation. Especially the USA have seen a surge in interest in Regenerative Agriculture from farmers, NGOs, and businesses. While articles and videos on the topic proliferate it has gained limited attention from scientists and no inquiry in the concept itself has been conducted.
This thesis explores the existing scientific and grey literature on the topic to provide an overview of Regenerative Agriculture’s genesis since its first emergence in the 1980s, contemporary understandings regarding definitions, principles and practices, and contextualizes Regenerative Agriculture with other concepts of alternative agriculture including organic farming, climate-smart agriculture, and Conservation Agriculture. The extensive literature review and qualitative content analysis reveal that Regenerative Agriculture is a currently highly dynamic, contested, and entails a large number of at times complementary, at times contradictory understandings. To be a meaningful contribution to the quest for sustainability the more radical contributions to this evolving concept like the large-scale transition to perennial-centred farming systems need to be accentuated without forfeiting the momentum of this emerging movement. This thesis humbly contributes to a scientific discourse on Regenerative Agriculture that is both benevolent and critical which is deemed necessary to develop realistic answers to urgent crises.
Ruminant livestock production is the most varied, complex, impactful, and controversial land use sector of our global food system today. Despite calls for improved sustainability across the sector, progress has been limited. Using a comparative qualitative analysis of ten expert-led case studies from diverse agroecological regions and production systems around the world, we propose a new framework to understand enabling conditions and opportunities for change. Contrary to prior work, we find that livestock production system type is insufficient to understand system constraints and opportunities. Instead, the proposed framework includes local, regional, and global economic and market context to understand the potential of interventions to facilitate change. Consideration of ecological (e.g. biome suitability for livestock, land condition, precipitation) and social and cultural factors (land tenure, cultural embeddedness of livestock) is also key. From these new insights, we recommend specific ways that policymakers, funders, and researchers can apply a context-based approach that considers multiple outcomes and perspectives to develop sustainable livestock policies, programs, and initiatives. This is needed to ensure equitable, durable, effective outcomes for people, biodiversity, and climate.
There is growing recognition of the need to achieve land use across the southern Australian rangelands that accommodates changing societal preferences and ensures the capacity of future generations to satisfy their own preferences. This paper considers the prospects for sustainable use of the pastoral lands based either on continued grazing or emerging, alternative land uses. After an overview of the southern rangelands environment, the status of the pastoral industry, its environmental impacts, and key issues for pastoral management, we propose four principles and 19 associated guidelines for sustainable pastoralism. Although some continued withdrawal of land from pastoralism is anticipated, we expect that pastoralism will continue throughout much of the region currently grazed, particularly in the higher rainfall environments in the east. Within these areas, sustainable pastoral land use should be achievable by the application of four broad management principles, as follows: (1) manage grazing within a risk management framework based on the concept of tactical grazing, (2) develop infrastructure to allow best management of both domestic and non-domestic grazing pressure, (3) incorporate management of invasive native scrub, where required, into overall, ongoing property management and (4) manage grazing to enhance biodiversity conservation at landscape scale. Application of these principles and guidelines will require the development of appropriate policy settings, particularly in relation to kangaroo management, climate change, and natural resource governance, together with innovative approaches to research, development and extension. Policy development will also be required if the new industry of carbon sequestration is to deliver socio-ecological benefits without perverse outcomes. Other emerging industries based on renewable energy or ecosystem services appear to have considerable potential, with little risk of adverse ecological consequences.
While the impact of livestock grazing has been frequently assessed for
grasses, little is known about how livestock affects tree seedlings and
saplings. We explored the effects of goat, cattle, and camel browsing
on the survival of Balanites aegyptiaca seedlings and saplings,
a broadleaved evergreen tree species indigenous to Sudan, in Dinder
Biosphere Reserve-Sudan (DBR). We used a stratified sampling design
with four sites: GOA (mainly browsed by goats), CAT and CAM being
mainly browsed by cattle and camels, respectively, while CON was
a control area without any livestock browsing. We tested the survival,
mortality, and recovery of seedlings and saplings across different sites.
Our results revealed that mortalities of seedlings in GOA were almost
four times higher than that of CAM and CON and twice that of CAT
(F3,196 = 100.39, P < .001). Further, sapling mortality was three times
higher in GOA than that observed in CAT and CON (F3,196 = 73.4,
P < .001). We found that seedlings recover better than saplings, and,
unexpectedly, goat browsing severely affected the natural regeneration
of B. aegyptiaca in DBR compared to other livestock species. Our
study findings contribute to sustainable forest management and show
that particularly goat browsing needs to be suppressed for the conservation
of vulnerable tree species.
Rangelands provide ecosystem services that are economically and ecologically critical for humans. Globally, invasion of exotic grasses drives loss of biodiversity and resilience of rangelands. In South Texas, buffelgrass (Cenchrus ciliaris syn. Pennisetum ciliare [L.] Link), a C4 perennial grass, was brought from Africa for range improvement as early as the 1930s. Buffelgrass generally increases forage biomass for livestock yet reduces habitat suitability for wildlife. Interest in controlling buffelgrass has increased due to its negative impacts on iconic wildlife, such as whitetailed deer (Odocoileus virginianus, Zimmermann 1780) and northern bobwhite (Colinus virginianus, Linnaeus 1758). The objective of this study was to evaluate the effect of a targeted grazing strategy that used buffelgrass and plant community phenology as indicators to determine the timing of cattle movement. On two private ranches in different ecoregions, we tracked targeted grazing versus light grazing in native-dominated and buffelgrass-dominated plant communities across variable precipitation through five growing seasons. We measured the effects of grazing type, plant community type, and precipitation on buffelgrass cover, native plant species richness, foliar cover, and Shannon diversity. Targeted grazing had a strong impact on diversity, increasing 0.37 ± 0.07 from a mean of H = 1.29 under the targeted grazing management. Conversely, buffelgrass cover was negatively correlated with Shannon diversity, decreasing it by 0.075 ± 0.03 for every 10% increase in buffelgrass cover from a mean of H = 1.29. Despite a variability in precipitation across seasons and years (93−455 mm), targeted grazing improved species richness and cover of native plants throughout the study. Our findings suggest that targeted grazing shows promise as an adaptive grazing strategy that reduces the impact of buffelgrass across highly variable precipitation. In unpredictable environments, management techniques that improve the resilience of plant communities through preserving biodiversity are critical.
The intensity of grazing management required for optimal pasture and animal production from heterogeneous native grasslands has received little research in the high-rainfall zone of south-eastern Australia. The aim of this experiment was to determine how the intensity of grazing management, from continuous grazing (P01) to flexible 4- and 20-paddock rotational systems (P04 and P20), influenced the productivity and sustainability of a Merino ewe, terminal sire lamb production system run on a native grassland dominated by Microlaena stipoides and Rytidosperma spp. The present paper focuses on the animal production and feed-quality results from this experiment. There was a higher per head animal production for the P01 than the P20, with the P04 being intermediate. The differences were found for ewe liveweight and fat score, lamb growth rates and lamb liveweight at weaning. The P20 was able to run higher ewe numbers, in response to greater feed on offer than for P04 and P01, which enabled lamb production per hectare at weaning to be similar and greasy wool production per hectare to be greater than for P01. The organic matter digestibility of the ewe diet estimated from faecal analysis was lower for P20 and P04 systems than for P01 over a 7-month period and explained differences measured in sheep performance at that time. When lambs were retained after weaning, they could be kept for longer on the P20 and grown to a greater weight than for the P01 and P04, but the criteria for setting stocking rates and selling lambs from systems influenced the production from the systems. Further work is needed to investigate the interaction between stocking rate (ewe numbers and lamb sale time) and grazing management and examine different options for managing rotational grazing systems.
Native pastures account for approximately half the grazing area of the high-rainfall zone of southern Australia and the appropriate intensity of grazing management to improve pasture production and to sustain native species composition is still debated. This paper describes differences in pasture herbage mass, ground cover and composition for a native pasture managed under three distinct grazing-management intensities (1-, 4- and 20-paddock grazing systems). Grazing-management treatments were implemented for 4 years across a variable landscape and the interaction of grazing management and landscape position (high-, medium- and low-production zones) were examined. Increasing the intensity of grazing management (number of paddocks in the grazing system) resulted in higher standing, green and litter herbage mass and ground cover of pastures, with differences most pronounced in the high-production zone where selective grazing was regulated with grazing management. Landscape position largely influenced pasture composition, with higher pasture production and more productive species (e.g. Microlaena stipoides, Lolium rigidum and legumes) in the high-production zone. Small increases in the DM of native perennial grasses and lower levels of legumes and broad-leaf weeds developed in the 20-paddock system compared with grazing in 1- and 4-paddock systems. Net pasture growth was higher in the 20-paddock than 1-paddock treatment during spring in the last 2 years of the experiment, resulting in 21% (1.6 t DM/ha) more herbage mass accumulated over the year. While productivity and cover were higher under intensive rotational grazing, grazing management had little influence on pasture composition. A stable perennial pasture (>70% perennial grasses) stocking rates that were not degrading and the strong influence of landscape on pasture composition limited management influences. Practically, the results indicated that, at the same stocking rate, increasing the intensity of grazing management can increase the average pasture herbage mass, ground cover and pasture growth by more evenly distributing grazing.
We evaluated the adequacy of rotational grazing to improve rangeland condition in the Flooding Pampa region, eastern Argentina, comparing the floristic composition dynamic of the 2 main plant communities under rotational and continuous grazing over a study period of 4 years (1993-1996). The experiment was conducted in commercial farms located in 4 sites of the Flooding Pampa region. In each site, a couple of farms, one managed under rotational grazing (implemented in 1989) and an adjacent one managed under continuous grazing at a similar stocking rate (1 AU ha-1), constituted the replications of the experiment. Basal cover of species, litter, and bare soil were monitored in midslope and lowland grassland communities on each farm. Total plant basal cover in midslope and in lowland communities remained unchanged over the whole experimental period under both grazing methods. Under rotational grazing, litter cover was higher in both communities while the amount of bare soil showed a significant reduction in lowlands and a tendency to be lower in midslope. Basal cover of legumes, C3 annual and C3 perennial grasses was higher, while cover of C4 prostrate grasses was lower under rotational grazing in the midslope community. In the lowland community, rotational grazing effects were evident only in the drier years, when higher cover of hydrophytic grasses and legumes and lower cover of forbs occurred. Plant species diversity did not change in response to grazing. In conclusion, rotational grazing promoted functional groups composed of high forage value species and reduced bare soil through the accumulation of litter. These changes indicate an improvement in rangeland condition and in carrying capacity. As the stocking rate was approximately 60% higher than the average stocking rate of the Flooding Pampa region, we believe that productivity and sustainability may be compatible by replacing continuous with rotational grazing.
Over 3 billion hectares of lands worldwide are grazed by livestock, with a majority suffering degradation in ecological condition. Losses in plant productivity, biodiversity of plant and animal communities, and carbon storage are occurring as a result of livestock grazing. Holistic management (HM) has been proposed as a means of restoring degraded deserts and grasslands and reversing climate change. The fundamental approach of this system is based on frequently rotating livestock herds to mimic native ungulates reacting to predators in order to break up biological soil crusts and trample plants and soils to promote restoration. This review could find no peer-reviewed studies that show that this management approach is superior to conventional grazing systems in outcomes. Any claims of success due to HM are likely due to the management aspects of goal setting, monitoring, and adapting to meet goals, not the ecological principles embodied in HM. Ecologically, the application of HM principles of trampling and intensive foraging are as detrimental to plants, soils, water storage, and plant productivity as are conventional grazing systems. Contrary to claims made that HM will reverse climate change, the scientific evidence is that global greenhouse gas emissions are vastly larger than the capacity of worldwide grasslands and deserts to store the carbon emitted each year.
Grazing system and stocking rate effects on forage standing crop of tallgrass prairies in north-central Oklahoma were evaluated from 1989 to 1993. Twelve experimental units, consisting of pastures dominated by big bluestem [Andropogon gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], indiangrass [Sorghastrum nutans (L.) Nash], and switch-grass [Panicum virgatum L.], were arranged in a completely randomized design with either a short duration rotation or continuous grazing system and stocking rates ranging from 127 kg animal live-weight/ha to 222 kg live-weight/ha. Yearling steers grazed the units from late April to late September. Herbage standing crop was sampled in July and September. Total, live, and dead standing crops did not differ significantly between the 2 grazing systems in July. Total standing crop was significantly higher in the rotation units in September (3,600 versus 3,020 kg/ha, P
Short-duration grazing (SDG) has been purported to increase forage production and utilization compared to other grazing systems, and thus can sustain higher stocking rates. This study was designed to determine if standing crop could be maintained as stocking rates increased. Four stocking rate treatments ranging from the recommended rate for moderate continuous grazing to 2.5 times the recommended rate were applied in a simulated 8-pasture SDG system. There was little change in frequency and composition of short-grasses over the study, but mid-grass frequency and composition both declined. Standing crop of all major forage classes declined as stocking rates increased. However, the rate of decline was less than proportional to the increase in stocking rate during the growing season. By fall, standing crop was inversely proportional to stocking rate, leading us to conclude that standing crop could not be maintained at the higher stocking rates. Low standing crop in the fall indicated a potential shortage of forage at the high stocking rates during the winter.
Tobosa (Hilaria mutica [Buckl.] Benth.) was seasonally grazed with cattle under high-density (2.1 to 5.1 animal unit/hectare [AU/ha]) rotation and low-density (0.33 and 0.39 AU/ha) continuous stocking in 1980 and 1981, respectively. Tobosa leaf and culm color were used to evaluate forage quality. At the end of the 1980-81 growing seasons, crude protein was highest in green tobosa (8.4%) and lowest in gray tobosa from the previous seasons (4.7%). Grazing strategies did not influence the proportion of green tobosa within the standing crop; however, flexible rotation produced a more uniform use of green tobosa within the cell when compared to grazing with fixed intervals between rotations. Grazing patterns result from improper utilization of green tobosa which in future years will senesce into gray colored tobosa that composed 46-91% of the standing crop. In this study, flexible rotation of cattle among paddocks, based on a 30-35% reduction of tobosa standing crop height, reduced gray tobosa within the standing crop more than did continuous stocking. Total heifer liveweight gain per ha in 1980 and 1981, respectively, was 43 and 24% less under continuous stocking compared to rotation grazing management.
The article presents a counter response to Allan Savory's statement that his planned grazing method was necessary to reverse desertification and climate change in the video 'How to green the world's deserts and reverse climate change' that was presented in session 7 at the 2013 TED (Technology, Entertainment, Design) Conference on February 27, 2013 in Long Beach, California. The pressing challenge is to develop broad approaches that can be implemented at multiple levels of social organization to minimize these pervasive and complex issues confronting rangeland sustainability. The tactic of discrediting science detracts from progress toward this goal, because it continues to oversimplify the complexity of rangeland systems and to promote narrowly focused technological solutions. Given that there are about five billion hectares of rangeland globally, it is relatively simple to calculate that each hectare of rangeland would have to sequester an additional two tons of C each year.
Improved carrying capacity of grasslands has been attributed to the effect of time-controlled grazing with high animal density, which can be achieved by increased stocking rates as well as by fencing. Therefore, a study was conducted to test the hypothesis that time-controlled grazing with high animal densities and high stocking rates will improve grassland condition. The study was made over a 6-year period on 3 sites with time-controlled grazing imposed. One site was on native grassland in the Fescue Prairie and 2 sites, 1 on seeded and the other on native grassland, were in the Mixed Prairie. On each site, stocking densities averaged 3,6, and 15 cow-calf pairs/ha, respectively, and stocking rates averaged 1.65,4.45, and 2.72 animal unit months/ha, respectively. Species composition and root mass and distribution were compared on grazed and protected areas within each site. Utilization averaged about 80% of available forage over the study period. Range condi-tion was less on grazed areas than on protected areas in the Fescue Prairie (38 vs 53% of climax) and in the Mixed Prairie (49 vs 53%). Average ash-free root mass, throughout the sampling profile, tended to be greater on the ungrazed vs the grazed area of the native Mixed Prairie site but not on the seeded Mixed Prairie or Fescue Prairie sites. The grazed areas of the Mixed Praiie sites tended to have more available phosphorus, possibly due to the application of manure, but less nitrogen and organic matter. The results led to a rejection of the hypothesis and a conclusion that high animal density and high stocking rates with time-controlled grazing would result in range deterioration.
The majority of native prairie has been lost throughout North America. Much of the remaining prairie is used for livestock grazing, so conservation of prairie species depends on sustainable grazing practices. Our objective was to evaluate the benefits of twice-over rotational grazing, in comparison with continuous season-long grazing and ungrazed “idle” fields, in conserving prairie songbirds. Northern mixed-grass prairie in southwest Manitoba, Canada is near the northern range limits for many endangered grassland birds, and thus is an important area for evaluating the contribution of twice-over grazing in the conservation of songbirds, including species at risk. In 2008 and 2009, we compared the relative abundances and diversity of grassland birds on 22 twice-over rotation, 15 season-long, and 8 ungrazed sites, using multiple 100-m fixed-radius point-count plots per site. Analyses were conducted using generalized linear mixed models. Although one obligate grassland bird, Savannah sparrows (Passerculus sandwichensis), had significantly higher relative abundances on twice-over than season-long sites in 2009, season-long pastures had higher species richness and diversity of obligate grassland birds in both years. Season-long grazing may actually benefit grassland bird communities by creating spatially heterogeneous but temporally stable areas of high and low livestock use within the pasture, thus increasing diversity of microhabitats. We found little evidence that twice-over grazing contributed to the conservation of grassland songbirds in subhumid northern mixed-grass prairies.
This commentary summarizes the evidence supporting holistic management (HM) and intensive rotational grazing (IRG) to demonstrate the extent to which Sherren and coauthors (2012) have overstated their policy endorsement of HM for rangeland application. Five major points are presented – distinction between HM and IRG, insufficient evaluation of the contradictory evidence, limitations of the experimental approach, additional costs associated with IRG, and heterogeneous capabilities and goals of graziers’ to manage intensive strategies – to justify why this policy endorsement is ill-advised. The vast majority of experimental evidence does not support claims of enhanced ecological benefits in IRG compared to other grazing strategies, including the capacity to increase storage of soil organic carbon.
Scientific interest in carbon sequestration on rangelands is largely driven by their extent, while the interest of ranchers in the United States centers on opportunities to enhance revenue streams. Rangelands cover approximately 30% of the earth's ice-free land surface and hold an equivalent amount of the world's terrestrial carbon. Rangelands are grasslands, shrublands, and savannas and cover 312 million hectares in the United States. On the arid and semi-arid sites typical of rangelands annual fluxes are small and unpredictable over time and space, varying primarily with precipitation, but also with soils and vegetation. There is broad scientific consensus that non-equilibrium ecological models better explain the dynamics of such rangelands than equilibrium models, yet current and proposed carbon sequestration policies and associated grazing management recommendations in the United States often do not incorporate this developing scientific understanding of rangeland dynamics. Carbon uptake on arid and semi-arid rangelands is most often controlled by abiotic factors not easily changed by management of grazing or vegetation. Additionality may be impossible to achieve consistently through management on rangelands near the more xeric end of a rangeland climatic gradient. This point is illustrated by a preliminary examination of efforts to develop voluntary cap and trade markets for carbon credits in the United States, and options including payment for ecosystem services or avoided conversion, and carbon taxation. A preliminary analysis focusing on cap and trade and payment for avoided conversion or ecosystem services illustrates the misalignment between policies targeting vegetation management for enhanced carbon uptake and non-equilibrium carbon dynamics on arid United States rangelands. It is possible that current proposed carbon policy as exemplified by carbon credit exchange or offsets will result in a net increase in emissions, as well as investment in failed management. Rather than focusing on annual fluxes, policy and management initiatives should seek long-term protection of rangelands and rangeland soils to conserve carbon, and a broader range of environmental and social benefits.
Infiltration rate decreased significantly and sediment production increased significantly on a site with a silty clay surface soil devoid of vegetation following periodic trampling typical of intensive rotation grazing systems. The deleterious impact of livestock trampling generally increased as stocking rate increased. Damage was augmented when the soil was moist at the time of trampling. Thirty days of rest were insufficient to allow hydrologic recovery. Soil bulk density, aggregate stability, aggregate size distribution and surface microrelief were related to the soil hydrologic response of the trampling treatments.
Two independent models concerning the effects of grazing on vegetation have gained wide acceptance in the last decade: Westoby et al.'s state- and- transition (ST) model, and Milchunas et al.'s generalized model of the effects of grazing on plant community structure and diversity (MSL model). These two prevailing models, as they stand, are conceptually divergent. The MSL model implicitly assumes that, at a given site, for each grazing intensity there is a single equilibrium situation with a single diversity value. The S-T model suggests that rangeland dynamics include irreversible transitions and alternative equilibria. Here we propose a modification of the original MSL model, to encompass a wider range of real situations and to place it within the context of the S-T model. The-four extreme cases proposed in the original MSL model are revisited, taking into account that (1) the "moisture" gradient can be generalized as a "productivity" gradient; (2) the selective pressure of herbivores on systems with long history of grazing has fluctuated over time, allowing the development of different pools of species adapted to low or high grazing intensities; and (3) systems with long evolutionary history of grazing. have developed resilience mechanisms that allow reversible shifts in floristic composition with changes in grazing intensities. The grazing intensity vs. diversity curves thus postulated for systems with a long evolutionary history of grazing are similar to those proposed by the original MSL model because resilience mechanisms allow for reversible changes associated with grazing intensity. In contrast, the curves postulated for systems with short evolutionary history. of grazing include different alternative branches, indicating irreversible transitions, because resilience mechanisms to grazing were not fully developed. By incorporating these modifications, the divergence between the original MSL and S-T models can be resolved. A set of published examples from real systems is presented and compared with the predictions of the modified model. The modified MSL model is applicable to a wider range of real situations than the MSL model in its original formulation.
Declining grassland productivity is a major concern in southern temperate Australia. Continuous grazing is thought to be a primary contributor to this decline, which is associated with the loss of perennial grasses. Landholders are evaluating grazing management strategies that might curb the loss of perennials and increase long-term productivity. This study reports on a comparison between continuous grazing and time-control grazing with sheep and cattle using a paired-paddock design at 5 locations in south-eastern Australia (lat. 30–42°S) over 6 years (1994–99). Pasture herbage mass, grassland species composition and basal cover of perennial grasses were assessed at 6-monthly intervals. Species abundance data were analysed by ANOVA, ordination (multi-dimensional scaling) and splining procedures to assess comparative trends between the 2 management treatments at each site. Species were categorised into major functional groups for analysis. Over all 5 sites there were few consistent differences between management treatments (continuous grazing v. time-control grazing). Basal cover was greater on the time-control grazing management compared with continuous grazing for most of the experimental period at 3 sites, but the initial values were also greater, resulting in a non-significant management × time interaction. Based on this study, we conclude that there was no apparent medium-term benefit of a multi-paddock rotational (time-control grazing) grazing system over continuous grazing for encouraging and maintaining a favourable botanical composition. The benefits for land managers from employing systems such as time-control grazing may accrue through other mechanisms. The study also highlights some of the difficulties with conducting on-farm paired-paddock research.
Megafaunal extinctions and a lack of suitable remote sensing technology impede our understanding of both the ecological legacy
and current impacts of large mammal herbivores in the Earth system. To address this, we reconstructed the form and intensity
of herbivory pressure across sub-Saharan Africa ~1000 years ago. Specifically, we modeled and mapped species-level biomass
for 92 large mammal herbivores using census data, species distributions, and environmental covariates. Trait-based classifications
of these species into herbivore functional types, and analyses of their biomass surfaces, reveal four ecologically distinct
continental-scale herbivory regimes, characterized by internally similar forms and intensities of herbivory pressure. Associations
between herbivory regimes, fire prevalence, soil nutrient status, and rainfall provide important insights into African ecology
and pave the way for integrating herbivores into global-scale studies.
Manipulating stocking rate and duration of grazing is fundamental to range management. It has been claimed that rotation grazing systems will increase stocking capacity of range while maintaining or improving animal gains, range condition, and forage production. To test these claims, we compared continuous, 4-pasture rotationally deferred, and 8-paddock short-duration rotation grazing on mixed-grass range near Cheyenne, Wyo. from 1982 through 1987. Grazing pressures ranged from 19 to 81 steer-days per tonne of forage dry matter produced. Steers were weighed biweekly; forage production, utilization, and botanical composition were estimated by clipping; and basal cover was estimated by inclined point frame. Basal cover of litter and bare ground responded to stocking rate or grazing systems, but basal cover of vegetation was affected only by years. Steer average daily gain decreased as grazing pressure increased (r2=0.66); systems had no significant effect. The most profitable stocking rate at 1986-87 costs and prices was approximately 60 to 80% above SCS recommendations, but the increase in return was small and range conditions and forage production probably could not be maintained at this rate.
The influence of short duration grazing (SDG), moderate continuous grazing (MCG), heavy continuous grazing (HCG), and grazing exclusion on infiltration rates of midgrass and shortgrass-dominated communities was evaluated over a 20-month period on the Texas Agricultural Research Station, located near Sonora in the Edwards Plateau, Texas. A combination of cattle, sheep, and goats were used in each grazing treatment. Infiltration rates were consistently less in the midgrass (bunchgrass) than in the shortgrass (sodgrass) community. The HCG pasture was severely overgrazed and infiltration rates were reduced to about one-half those in the MCG pasture. The midgrasses in this pasture were destroyed after 26 months of overgrazing. Infiltration rates in the SDG pasture, stocked at double the recommended rate, decreased during the study period. Infiltration rates in the SDG pasture shortgrass community, near the end of the study, approached those in the HCG pasture. The greatest infiltration rates for both communities were maintained in the MCG pasture. Infiltration rates for the midgrass community remained relatively stable during the study when the general trend in the SDG and HCG pastures was toward reduced infiltration rates. The nongrazed pasture subsequent to the 1980 drought had a general increase in infiltration rates.
By focusing on process-oriented data rather than inventory-type data, this study provides a robust understanding of the effects of agricultural management on grassland bird reproductive output in the moist highland grasslands (MHGs) of South Africa. Four-hundred and four nests of 12 grassland-breeding bird species were monitored in five different land-use types. Survivorship was modelled using Program MARK to assess the effects of these management practices on reproductive performance. Six of the species were modelled individually to assess speciesspecific responses. Both nest-site selection and nest success were driven by vegetation structure, which in turn is driven by habitat management. There was an increase in nesting success through the season for cup (ground) nesting birds as vegetation structural complexity increased through the breeding season (September to March). Nest success was driven by predation pressure rather than food availability. Analysis of the nesting success of the Yellow-breasted Pipit Anthus chloris indicated that unconserved areas house sink populations, confirmation of which would depend on a measure of adult survival. The generalist African Pipit Anthus cinnamomeus, on the other hand, thrived in disturbed, communally grazed lands. To conserve MHG bird species, managers should maintain a mosaic of burning regimes, with the majority burning biennially or less frequently.
The South African grassland system is home to over 3,300 plant species, 15 of the country's 34 endemic mammal species, 12 of the 40 endemic bird species (four of which are globally threatened) and five RAMSAR wetland sites. To assess and address the ecological integrity of farmed grasslands we used process-oriented techniques, including nesting success and field metabolic rates (FMR) of birds, and an adaptation of the multi-taxon biodiversity intactness index (BII) using plant, arthropod and bird diversity data which is a comprehensive tool for assessing ecological integrity using multiple taxonomic groups. Current pastoral management practices have a significant detrimental effect on avian abundance, species richness, nest density and fledgling output. Overall energy turnover and BII values confirm the importance of conserved areas for birds in moist highland grassland systems and support the need for further conservation efforts in grassland systems by both private landowners and reserve managers. Findings based on both avian FMRs and the BII in this study were found to be comparable, lending support to the use of FMR as a rapid assessment technique for assessing ecosystem integrity for future
Total and average daily gains of Hereford/Angus crossbred growing heifers were contrasted between a continuously grazed (CG) treatment and a 10-pasture, 1-herd rapidly rotated short duration grazing (SDG) treatment. Stocking rate in the CG was 0.48 ha/AUM, a moderate rate, while stocking rate in the SDG treatment was 0.24 ha/AUM. Trials were conducted during the 1978 and 1979 growing seasons. Both total and average daily gains were similar in both treatments both years. Because of the two-fold difference in rate of stocking, production/ha was approximately double in the SDG to that in the CG treatment. It is tentatively concluded from the results of this and previous studies that a properly managed SDG system may satisfactorily support livestock at rates of stocking appreciably greater than that normally expected from conventional grazing schemes.
A review of pertinent literature shows that grazing systems and grazing intensities both influence herbage production on Western ranges. Mean annual herbage production increased by 13% when grazing systems were implemented at a moderate stocking intensity. Increases were larger (35% and 27%) when continuous livestock use was reduced from heavy to moderate, and moderate to light, respectively. This suggests that adjustments in livestock numbers have a greater effect on herbage production than do grazing systems.
Understanding the temporal response of vegetation to selected livestock grazing strategies is necessary for the continued maintenance or increased productivity of rangelands. Vegetation cover and above-ground biomass were sampled bimonthly from 1978-1984 on pastures grazed continuously (MCG) and moderately stocked (8.1 ha ); continuously (HCG) and heavily stocked (4.6 ha ); high-intensity, low-frequency (HILF) and moderately stocked (8-1; 17:119 day stocked at 8.1 ha ); short-duration grazing (SDG) and heavily stocked (14-1; 4:50 day, stocked at 4.6 ha ); and livestock exclusion (LEX). Prior grazing history, vegetation cover, soils, and slope were similar among pastures. Midgrass cover was eliminated in the HCG pasture, and declined in the heavily stocked SDG pasture. Midgrass cover was maintained under the moderately stocked HILF grazing strategy and increased under MCG or LEX. During 1984, sideoats grama (Bouteloua curtipendula (Michx.) Torr.) basal diameter in the MCG and LEX pastures was significantly greater than in the SDG pasture. By the end of the study, total organic cover and total aboveground biomass in the MCG or LEX pastures were significantly greater than in the SDG and HCG pastures. The heavy grazing intensity used in this study, regardless of the grazing strategy, does not appear suited for long-term maintenance of midgrass species.
The effects of stocking rate and grazing method on performance of yearling beef cattle grazing tallgrass prairies in north-central Oklahoma were evaluated from 1989 to 1994. Pastures dominated by big bluestem [Andropogon gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], and indiangrass [Sorghastrum nutans (L.) Nash], were allocated to either short duration rotational or continuous stocking methods and stocking rates ranging from 52 animal-unit-days (AUD) ha-1 to 90 AUD ha-1. Steers grazed the units from late April to late September. Precipitation was above average during the study period. Live weight gain per head was higher under continuous stocking than rotational stocking at all stocking rates. At 52 AUD ha-1, individual gains under rotational stocking were 11% less than under continuous stocking. At 90 AUD ha-1, individual gains under rotational stocking were decreased by 20%. Measurements of steer diets and forage standing crop suggest the reduction in weight gain was due to reduced forage intake under rotational stocking. Live weight gain per hectare increased with stocking rate and was higher with continuous stocking at all stocking rates. Net returns per hectare increased as stocking rate increased for both stocking methods but were lower for rotational stocking at all stocking rates. Variable costs per head would have to decrease by 24 to 34% under rotational stocking to equalize net returns between the 2 grazing methods. Unless the decline in gain per head can be reduced or eliminated, there is no economic incentive to implement rotational stocking under the conditions of this study.
Rotation grazing strategies have been proposed to increase stocking capacity, improve animal gains, and improve forage production and range condition. We compared continuous or season-long, 4-pasture rotationally deferred, and g-paddock time-controlled rotation grazing on mixed-grass rangeland near Cheyenne, Wyo. from 1982 through 1994. Stocking rates under light, moderate and heavy grazing averaged 21.6,47.0, and 62.7 steer-day ha-'; grazing pressures were 11.0 to 90.1 steer-day Mg-' of forage dry matter produced. We estimated above-and below-ground biomass, botanical composition and basal cover. Bare ground and cover of warm-season grasses, forbs, and lichens were greater under heavy stocking; cover of litter, western wheatgrass, and total cool-season graminoids were greater under tight stocking. Stocking rate and grazing strategy had no effect on above-ground biomass and little effect on below-ground bio-mass. Under heavy stocking, percent of above-ground biomass contributed by forbs increased, especially under time-controlled rotation grazing, and that of western wheatgrass decreased. Otherwise+ effects of grazing strategy, level vs. slope, and north vs. south slope on vegetation were insignificant. Steer average daily gain decreased linearly as grazing pressure increased (3 = 0.44); grazing strategies had no significant effect. When cattle prices are favorable, the stocking rates that are most profitable in the short run may be high enough to reduce range condition.
Reduced pasture size and distance to water may be responsible for the alleged benefits of intensive time-controlled rotation graz-ing systems. We compared cattle gains, activity, distance traveled, and forage utilization on a time-controlled rotation system with eight 2&a pastures, on two 24-ha pastures grazed continuously (season-long), and on a 207-ha pasture grazed continuously, all stocked at the same rate. Utilization on the 207-ha pasture, but not on the 24ha pastures, declined with distance from water. At dis-tances greater than 3 km from water in the 207-ha pasture, utgiza-tion was significantly less than on adjacent 24ha pastures, at distances of 1.0 to 1.6 km from water. Cows on the 2071a pasture travelled farther (6.1 km/day) than cows on the 24ha rotation pastures (4.2 km/day), which travelled farther than cows on the 24ha continuously grazed pastures (3.2 km/day). Grazing system, range site, slope, and weather had minimal effects on cow activity patterns. Gains of cows and calves were less on the 207-ha pasture (0.24 and 0.77 kg/day, respectively) than on the 24ha rotation pastures or 24-ha continuously grazed pastures (0.42 and 0.89 kg/da, respectively), with no differences between the latter. Calcu-lated "hoof action" on the rotation pastures was less than that demonstrated to increase seed burial and seedling emergence. Intensive rotation grazing systems are unlikely to benefit animal performance unRss they reduce pasture size and distance to water Manuscript accepted 16 May 1992.
Vegetational response of a nine-paddock, short-duration grasing cell was compared to that of a continuous pasture for 8 g-year period in southcentral New Mexico. Differences in vegetational response to short-duration and continuous grazing on blue grama rangeland were small. Basal plant cover was slightly higher for the short-duration pastures, but end-of-season standing crop of all species was similar for both systems. Blue yama aboveground productivity and basal cover were higher for the short-duration pastures than for the continuously-grazed pasture. Possible short-term results from short-duration grazing include slightly higher stocking rates and a positive response of blue grama.
Examined the frequency and intensity of defoliation of western wheatgrass Pascopyrum smithii and blue grama Bouteloua gracilis tillers under continuous season-long and time-controlled short-duration rotation grazing by steers at two stocking rates. Under heavy and moderate stocking, respectively, 19% and 36% of western wheatgrass tillers and 42% and 54% of blue grama tillers were ungrazed throughout the grazing season. Few western wheatgrass tillers were grazed more than twice, and few blue grama tillers were grazed more than once. Stocking rates have much greater potential than grazing systems for altering frequency and intensity of defoliation and subsequent changes in botanical composition of range plant communities. -from Authors
Over the last few years there has been an ever-increasing interest in America in the Savory Grazing Method. During the recent annual meeting of the Society for Range Management in Albuquerque, N. Mex., nearly 500 people visited the nearby SGM scheme operating on tribal Indian land. As a consequence of such interest I have been invited to write this article for Ran gelands. I do so in the hopes of expanding understanding and of clearing some of the many myths and misconceptions about SGM abounding in the profession and amongst ranchers. For all conservationists, as well as livestock owners, an answer to the desertification problem has long been sought. It is needed to stop our dams silting, our water tables dropping ever-lower, our wildlife being increasingly threatened and to aid the millions of people living in abject poverty on drying lands in the Third World. Even America will soon realize that water is her Achilles heel and that her wealth and prosperity are dependent upon sta-ble catchments. In Holistic Resource Management (SGM), we undoubtedly have an economically sound, self-sustain ing answer to the desertification problem for America as well as the poorest nations bedevilled with it. The fate of many countries depends on how SGM is developed and extended from America. Unfortunately, for some reason America is a nation of extremes where people en masse rush into new things often with enthusiasm unmatched by knowl-edge, then after a few tragedies react en masse the other way. Generally the American attitude to SGM has been no dif-ferent. Many have rushed into SGM too fast and with too little knowledge. Most of the knowledge available to the average rancher or university is misinformation and myth spread by the universities themselves, i.e., "SGM is a wagon wheel system; SGM is a cell grazing system; SGM is short duration grazing; SGM is rapid rotation grazing," and so on. All of these descriptions are totally wrong. Yet how many ranchers, government agencies and universities do you know who have rushed into it in the belief that it is one or livestock on the land. It is riparian and fish management technique. It is also a method of managing livestock on the land whereby the livestock can be used to reverse the deser-tification process very economically with or without fencing. It is also a method of managing livestock on ranges or on planted pastures whereby greater production can be achieved both from the land and the animals and with greater profitability than conventionally. It is a method of making conventional range management techniques economically sound where they were economically unsound. It is not just another grazing system, of which there have been so many. Throughout the world there are vast areas of what are known as the "brittle environments". These are areas where there are prolonged periods of the year in which conditions for plant growth are adverse. In the most brittle of these areas periods adverse for plant growth occur in the growing sea-son as well as during the long non-growing season. Most of these areas are associated with arid and semi-arid climates but some can extend into remarkably high rainfall zones. Throughout America and the rest of the world these brittle environments are mainly used for livestock production. Throughout, they are deteriorating, become drier, carrying fewer and fewer animals and in fact becoming deserts to varying degrees and at varying rates.
1. Soil resource availability and disturbance are widely recognized as key drivers of plant community structure. However, the relative importance of different plant traits in determining species abundance following shifts in soil resource availability and disturbance remains little studied, particularly in long-term experiments.
2. We studied trait-based plant community assembly in a 27-year grassland experiment where 25 plant species were sown into resident vegetation, after which annual manipulations of soil resource availability (five levels of superphosphate fertilizer; the highest level was also irrigated) and disturbance (three ‘mob-grazed’ sheep grazing intensity levels: lax, moderate, hard) were applied. We used community assembly through trait selection (CATS) models based on entropy maximization to predict species relative abundances and to quantify the relative importance of each trait in determining abundance.
3. Plant species were primarily differentiated along a trade-off axis corresponding to traits promoting rapid growth (e.g. high leaf [N] and specific leaf area [SLA]) vs. those promoting long leaf life span. Using 12 traits, the CATS model predicted >80% of the variation in the relative abundances of 51 species, suggesting that trait-based filtering was important.
4. Species with leaf attributes that reduce nutrient losses held a long-term advantage under the lowest soil resource availability, whereas those associated with a rapid growth rate became dominant under soil resource addition. Species with thinner leaves were also favoured under greater soil resource availability, which may reflect a strategy to maximize SLA without sacrificing leaf density and thus maintain leaf structural defences under grazing disturbance. Greater leaf [S] and the ability to symbiotically fix atmospheric N were favoured under greater soil resource availability. Greater plant height, thinner leaves and higher leaf [N] were favoured under lower grazing intensity.
5. Synthesis. Our results highlight the importance of species functional differences to understand how plant communities react to increases in soil resource availability and disturbance, two important and inseparable components of land-use change in grasslands world-wide.
In this study, we investigated the responses of two faunal groups, birds and arthropods, to varying degrees of disturbance caused by fire and grazing in South Africa, eight study sites of varying fire frequency and stocking density were studied over two summer seasons (October–March). Bird assemblages reflected habitat disturbance in a diversity of ways, driven by factors ranging from direct disturbance to changes in habitat structure and functioning, and shifts in food availability. Similarly, arthropod diversity and abundance changed seasonally in response to management practices. Fire frequency drives faunal assemblage structure and abundance and, in most cases, overrides the effects of grazing at all taxonomic levels. In particular, fire frequency strongly influenced grassland-breeding birds because farms are burnt in the territory-forming stage of the breeding cycle. Insectivores and nectarivores were disproportionately impacted by intensive commercial management. Of particular concern in this system is the yellow-breasted pipit (Anthus chloris), which is regionally and globally Vulnerable because of habitat loss. This species is sensitive to any form of habitat disturbance, highlighting the need for conservation attention in these grasslands. Of the ten arthropod orders present in the study area, only Orthoptera responded positively to burning. However, orthopterans made up on average 78% of arthropod biomass in moist highland grasslands, resulting in high grasshopper biomass on annually burnt farms: this high biomass in turn supports an abundance of insectivores. This reinforces the importance of process-oriented data where a measure of performance, such as reproductive success, is considered in assessing ecosystem condition.
We evaluated the adequacy of rotational grazing to improve rangeland condition in the Flooding Pampa region, eastern Argentina, comparing the floristic composition dynamic of the 2 main plant communities under rotational and continuous grazing over a study period of 4 years (1993-1996). The experiment was conducted in commercial farms located in 4 sites of the Flooding Pampa region. In each site, a couple of farms, one managed under rotational grazing (implemented in 1989) and an adjacent one managed under continuous grazing at a similar stocking rate (1 AU(.)ha(-1)), constituted the replications of the experiment. Basal cover of species, litter, and bare soil were monitored in midslope and lowland grassland communities on each farm. Total plant basal cover in midslope and in lowland communities remained unchanged over the whole experimental period under both grazing methods. Under rotational grazing, litter cover was higher in both communities while the amount of bare soil showed a significant reduction in lowlands and a tendency to be lower in midslope. Basal cover of legumes, C-3 annual and C-3 perennial grasses was higher, while cover of C-4 prostrate grasses was lower under rotational grazing in the midslope community. In the lowland community, rotational grazing effects were evident only in the drier years, when higher cover of hydrophytic grasses and legumes and lower cover of forbs occurred. Plant species diversity did not change in response to grazing. In conclusion, rotational grazing promoted functional groups composed of high forage value species and reduced bare soil through the accumulation of litter. These changes indicate an improvement in rangeland condition and in carrying capacity. As the stocking rate was approximately 60% higher than the average stocking rate of the Flooding Pampa region, we believe that productivity and sustainability may be compatible by replacing continuous with rotational grazing.
This study evaluated the efficacy of prescribed fire applied within landscape-scale rotational grazing treatments to reduce mesquite (Prosopis glandulosa Torr.) encroachment and restore herbaceous productivity and cover. One-herd, multiple-paddock rotational grazing was used to accumulate herbaceous fine fuel for fires via prefire deferment and to provide periodic postfire deferment for grass recovery. Treatments were an unburned continuous-grazed control, a four-paddock-1 herd system with fire (4:1F), and an eight-paddock-1 herd system with fire (8:1F), with two replicates per treatment (1294-2130 ha per replicate). The management plan was to burn 25% of each system (one paddock in the 4:1F; two paddocks in the 8:1F treatments) and defer grazing during all or portions of the 9 mo (May to January) prior to burning. Deferral was internalized by grazing on the remaining 75% of each treatment without reducing stocking rate determined for the entire system. Mesquite cover increased on clay-loam soils from 22% to 40% in unburned paddocks over 7 yr (1995-2001). This increase, coupled with extended drought, reduced fine fuel amounts for fire and limited the number and intensity of fires that were applied. It was possible to burn one paddock in the 8:1F treatment (12.5% of total area), but not in the 4:1F treatment (25% of total area) during drought. Fires reduced mesquite and cactus (Opuntia spp.) cover by 25-79% and 24-56%, respectively, but cover of these species increased to prefire levels within 6 yr. All fires reduced (P≤0.05) total herbaceous biomass for 1 yr postfire. The 8:1F treatment increased (P≤0.05) grass biomass on loamy-bottom soils and reduced (P≤0.05) bare ground on clay-loam and loamy-bottom soils in unburned paddocks compared to the unburned continuously grazed control. The 8:1F treatment, through internalized grazing deferment, facilitated the application of fire to reduce woody cover during extended drought without degrading the herbaceous understory.
In a grassland–oak savanna in southeastern Arizona, we compared vegetative ground cover and bird populations between a 29-year livestock exclosure and an adjacent cattle ranch that was managed according to the principles of holistic resource management, including short-duration rotational grazing. The study took place in the winter after a 2-year drought and 1 year after the drought ended and stocking densities were reduced. During the first winter, grasses on the livestock exclosure were taller (4.4 times) and had higher basal area ground cover (2.5 times), canopy cover (2.2 times), and reproductive canopy cover (10 times) than in the grazed area. These differences persisted into the second winter but at lower levels. As a group, 19 species of ground-foraging, seed-eating birds (e.g., doves, quail, sparrows, towhees) were 2.7 times more abundant on the exclosure than on adjacent grazed grasslands during the first winter. These same species were 1.7 times more abundant on the exclosure during the second winter and were 2.9 times more abundant on both sites combined after the drought had ended. A second group of 24 avian species with different foraging ecologies (e.g., predators, frugivores, arboreal insectivores) did not differ between treatments or years. High-density, short-duration rotational grazing, coupled with a drought, left the land in a substantially denuded condition through two winters and negatively affected a variety of resident and migratory birds dependent on ground cover and seed production for over-winter survival.
Grazing management practices modify soil structure, which, in turn, alters the behaviour and population dynamics of soil‐inhabiting organisms. Monitoring of changes in abundance and richness of soil organisms is vital in determining the sustainability of grazing regimes. In this paper, populations of soil organisms were compared—using abundance and population trends as an indicator of diversity—in two different grazing practices (a) conventional, set stocked (SS) grazing regime and (b) high intensity‐short duration (HI‐SD) grazing regime) and an ungrazed control (C). A thorough sampling of earthworms and arthropods, and an assay of soil microbial biomass and respiration was made in Spring 2004 (September‐November), after a pilot sampling of earthworms and arthropods in Autumn 2004 (March‐May). Earthworm numbers were found to be unaffected by grazing regimes, however, microarthropod abundance at 0–10 cm soil depth was significantly higher in soil of the HI‐SD grazing regime and in the ungrazed control, when compared with set stocking. Microbial biomass and respiration did not differ across treatments. Overall, our results indicate that arthropod abundance reflects the changes impacting on soil structure as a consequence of grazing practice. Evaluation of earthworm populations was not found to be useful in discriminating between the two grazing regimes, because the earthworm numbers were principally affected by rainfall.
Holistic Resource Management (HRM) is a process of goal setting, decision making and monitoring which integrates social, ecological and economic factors. Biodiversity enhancement is a fundamental principle in HRM and students are taught that biodiversity is the foundation of sustainable profit. In the HRM process, practitioners develop a holistic goal which includes: (1) quality of life values, (2) forms of production to support those values, and (3) landscape planning, which should protect and enhance biodiversity and support ecosystem processes of succession, energy flow, hydrological and nutrient cycling. We present an overview of the HRM model and results of interviews with 25 HRM farmers and ranchers from across the USA in which perceptions and experiences with respect to the role of biodiversity in the sustainability of their operations were explored. An ethnographic approach and qualitative research methods were used in the interviews. While only 9% of the interviewees reported thinking about biodiversity in the context of their operations before being exposed to HRM, now all of them think biodiversity is important to the sustainability of their famrs and ranches. Of the people interviewed, 95% perceived increases in biodiversity (particularly with respect to plants) and 80% perceived increase in profits from their land since HRM began influencing their decisions. In addition to perceiving increases in biodiversity, all of the interviewees reported observing indications of positive changes in some of the ecosystem processes on their farms or ranches. In addition, 91% of the interviewees reported improvements in their quality of life because of changes in their time budgets. Three of the interviewees who had quantitative data on changes in numbers of plant species and economic indicators are discussed in detail. We conclude that holistic management approaches like HRM are worthy of further study.
The Senegal River is a major natural resource in West Africa where the principal economic resources are agricultural. A proposed irrigation project will provide a significant increase in crop production and will exert a large influence on the economics of Senegal, Mauritania, and Mali. The magnitude of benefits from the project will depend upon the allocation, scheduling and managing of that portion of the water to be used for irrigating agricultural crops. A procedure is recommended for estimating crop water requirements that only requires the measurement of maximum and minimum temperatures. This procedure although calibrated for the Senegal River Basin using climatic data from four representative locations appears to be generally applicable for other areas without calibration. The importance of rainfall in supplying part of crop water requirements is described. Mean, actual dependable and effective precipitation values are compared for one location. Block farming or the planting of a single crop to manageable areas should be made mandatory. Project managers must assume responsibility for implementing procedures to insure good productivity and reasonable efficiencies.