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The necessity and possibility of perennial grain production systems

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... Several papers published in the March 2005 issue of Renewable Agriculture and Food Systems (RAFS) (DeHaan et al., 2005;Cox et al., 2005;Crews, 2005;Glover, 2005) follow a theme that conventional agriculture, as practiced in the temperate zone with annual crops and nitrogen fertilizer, inadequately protects our landscapes and rivers. The authors propose an alternative based on perennial grain crops grown in complex polycultures with a grain legume as the source of nitrogen (N). ...
... That objective has not been achieved and is clearly a difficult challenge. The goal outlined by Jackson (1980) has made work of the Land Institute even more difficult by spreading its few efforts over a wide range of species and objectives (DeHaan et al., 2005;Cox et al., 2005;Crews, 2005;Glover, 2005;Jackson, 1980). A focus on perennial polycultures, which will require a whole set of new grains rather than just one, also serves to strongly diffuse efforts and hamper progress. ...
... He has written of the beauty of natural prairie and his presumptions about high productivity, stability, limited erosion, and tightness of nutrient cycling in those systems. Perennation (with continuous protection of the soil and deep rooting) and diversity are held to be responsible for most of those benefits (Glover, 2005). These ideas launched the Land Institute's efforts to achieve similar benefits for agriculture through a prairiemimic polyculture. ...
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Perennial grains and polyculture were proposed ( Renewable Agriculture and Food Systems 20 (1), March 2005) as alternatives to annual grain systems. The authors criticized current annual systems as unsustainable and pointed to native prairies as a model sustainable system with no added input and little negative environmental impact. That portrayal is short-sighted. All previous efforts to breed perennial grains have resulted in crops incapable of supporting both a perennial life-habit and grain yield sufficient to address food needs. Analyses of production/uptake and partitioning of C and N resources within perennial crops confirm that a trade-off between the C and N needs of perennation and grain yield will limit efforts to create productive perennial grains. As a result, incorporating perennial life-habit into grain crops would severely constrain world food production unless the area put to farming was greatly increased. In addition, pest- and risk- management problems, which escalate when sanitizing benefits of crop rotation are abandoned, are exacerbated in polyculture. Although grains contain only small concentrations of nutrients, the amounts exported in crop yields are large. If yield is to be maintained, external inputs are essential, regardless of life-habit. Polycultures of perennial grains are seen to have little potential for producing sufficient food to serve as alternatives for current production systems.
... One-third of the earth's arable land resources has been already severely degraded in consequence of agricultural conversion to annual cropping systems (Pimentel et al. 1995). This includes dramatic adverse effects on essential ecosystem services such as water shortage and pollution through eutrophication, carbon and nutrient losses through soil management, contamination with agrochemicals, and climate-relevant greenhouse gas emissions (Glover 2005, Gomiero et al. 2011. Concomitantly, the continuing global growth of the human population will boost these ecological problems since, by 2050, one billion hectares additional land will be required to meet global food and energy demands (Naylor et al. 2007, Godfray et al. 2010. ...
... A fundamental understanding of the multiple and complex biotic interactions may provide the opportunity to refine breeding objectives, to manipulate specific functional traits, and to adjust soil management options. These refer to interactions of the crop with microorganisms, arthropod pests, natural enemies, pollinators, and weeds, which either promote or threat the agronomic performance of perennial grain crops (Glover 2005. Similarly, effects of perennial grain cropping on functional and natural biodiversity of the agroecosystem and its contribution to habitat conservation remain elusive (Glover 2005, Pimentel et al. 2012, Culman et al. 2013, Kantar et al. 2016. ...
... These refer to interactions of the crop with microorganisms, arthropod pests, natural enemies, pollinators, and weeds, which either promote or threat the agronomic performance of perennial grain crops (Glover 2005. Similarly, effects of perennial grain cropping on functional and natural biodiversity of the agroecosystem and its contribution to habitat conservation remain elusive (Glover 2005, Pimentel et al. 2012, Culman et al. 2013, Kantar et al. 2016. ...
Article
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Compared to their annual analogues, perennial grain cropping systems provide various beneficial attributes for the environment and ecosystem services related to resource use efficiency, soil erosion, and soil conservation. However, there is only limited understanding of the multiple biotic interactions in perennial cropping systems and their potential effects on the crop, involving plant growth-promoting and pathogenic microorganisms, beneficial and detrimental faunal organisms below- and above-ground, weeds, and overall biodiversity effects. We use information from studies carried out in managed and natural perennial systems of analogous structure such as perennial energy crop production systems and grasslands to highlight and specify biotic interactions and processes, which potentially constitute advantages and constraints in developing perennial grain cropping systems. Concerning the relevance of soil microorganisms and potential perennial crop breeding goals, we focus on a range of plant–microbe interactions in the rhizosphere involved in biofertilization, phytostimulation, and biological control of soil pathogens. We consider relationships within the faunal community emphasizing arthropod pests and their natural enemies, as well as crop–weed interactions. Based on these outcomes and in comparison with annual systems, we discuss and compile benefits, options, and limitations of management of crop-associated biotic interactions and biodiversity, which might contribute to reproducible and sustainable effects of perennial grain crop productivity. We conclude that management strategies for perennial grain cropping systems depend much more on ecological processes and interactions operating in natural ecosystems than those in annual cropping systems. Consequently, the use of agrochemicals for pest, weed, and disease control, as well as the use of synthetic fertilizers, counteracts the principle functions of the system and would strongly degrade the potential of biotic benefits. We also found that there is only vague information on the long-term productivity and cultivation period of perennial grain crops, the specific management operations of replacement, and the potential development and management of weed and pest populations. Overall, an advanced understanding of interactions between the crop and its biotic environment provides the opportunity to manipulate specific functional traits of crop-associated organisms for improved management and crop productivity, but significant research challenges for implementation of perennial grain crops still remain.
... Proponents argue that sufficiently productive perennial grain systems can be developed to better mimic the structure and function of natural ecosystems and thus greatly reduce soil erosion, nutrient losses, and degradation of soil quality associated with annual grain systems. These arguments were advanced in a series of four articles published in the March 2005 issue of Renewable Agriculture and Food Systems (RAFS) (Glover, 2005;De Haan et al., 2005Crews et al., 2005). Since then, perennial grain proponents continue to extol the virtues of natural ecosystem mimicry and improved environmental performance of perennial crops as justification for research and development investment in perennial grains (FAO, 2014;FAO, 2019). ...
... Without adequate yielding ability in several consecutive years to replace a substantial proportion of annual grain production, perennial grain systems would be limited to niche health-food markets in wealthy countries. As stated by Glover (2005): "All recognize that high seed yields are a basic requirement for successful widespread adoption of perennial grain crops." And while nutrient supply, insect and disease management are seen as challenges that can also be overcome through R & D Crews, 2005), these factors are secondary to the challenge of achieving high-yielding perennial grains. ...
... Based on thorough review of the literature, Loomis (2022) identifies several reasons why yields of perennial grain crops are so much lower than yields achieved by wellmanaged annual grains. In contrast, Glover (2005) argues that it is possible to overcome these challenges if the power of recent advances in genetics and computational sciences are brought to bear: "Modern plant breeders, unlike those earliest plant breeders, have recent advances in plant breeding, unprecedented computational power and a greater understanding of ecology, cytogenetics and molecular biology to make high-yielding perennial grain crops possible. " De Haan et al. (2005) provide more detail about specific approaches to overcome physiological "tradeoffs" between perenniality and grain yield. ...
Article
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Perennial grain crops have been proposed as environmentally sustainable alternatives to annual grain crop systems that currently dominate the world's major breadbaskets. Proponents emphasize the potential of perennial grains to mimic natural systems and thereby reduce soil erosion, nutrient losses, and degradation of soil quality although need for adequate grain yield is also recognized as a prerequisite for success. Here we assess progress since 2005 (16 y) towards development of perennial grain systems with sufficient productivity to be seen as competent alternatives to annual wheat on the prairies and plains of North America and Australia. Based on reports published in refereed journals, we see little evidence that yield of Intermediate Wheatgrass or perennial wheats have improved to the point they are viable alternatives. Slow progress is attributed to lack of minimum grain yield targets for economic viability, lack of designated target regions where perennial grains are most likely to be competitive against annuals, selection methods that focused on components of yield rather than yield per se (i.e. on an area basis), and relatively small R & D investment compared to resources given to genetic and agronomic improvement of major annual grain crops. Given current status, we conclude that perennial grains will require substantial R & D investment and several decades if they are to achieve sufficient yield potential and yield persistence to become more than a niche crop for upscale health food markets in wealthy countries.
... Dit kan een probleem geven bij de verwerking van het zaad (Cox, T.S. et al, 2006). Het succes van meerjarig graan staat of valt bij een voldoende hoge zaadopbrengst, zoals eigenlijk iedereen onderkent (Glover, J.D., 2004). ...
... Zo zijn goede enkeljarige graansoorten elk jaar opnieuw uitgezaaid, hoewel dat voor meerjarige graansoorten niet van belang was. Deze hoefden namelijk niet telkens opnieuw uitgezaaid te worden (Glover, J.D., 2004en Cox, T.S. et al, 2006. Kunzig (2011) onderkent dit probleem. ...
... Ook zouden meerjarige granen de mogelijkheid hebben om een nutriëntencyclus op te zetten en zo minder afhankelijk zijn van verschillende meststoffen (Glover, J.D., 2004). Cox et al (2006) onderstrepen dit in een onderzoek waarin vergeleken wordt wat de verschillen zijn in gebonden stikstof en gebonden koolstof tussen enkeljarig graan en een meerjarige hooiweide. ...
Article
In een deskstudie en met twee veldproeven is nagegaan wat de mogelijkheden zijn van meerjarig graan in Nederland. Meerjarig graan is een gewas dat na de oogst weer nieuwe spruiten vormt zoals graszaad.
... Other approaches tackle technical issues aiming at preserving soil quality (e.g.,[8,70]), including the adoption of different farming practices, such as agroecology (e.g.,[120,121]), organic farming (e.g.,[122][123][124][125]) and precision agriculture (e.g.,[60,126]). The use of alternative crops, such as perennials, has also been proposed as a sustainable practice to preserve soil and reduce inputs (e.g.,[127][128][129][130]). According to Eswaran et al.[131], two main schools of thought exist concerning the way to approach soil degradation and its impact. ...
... Soil erosion rate for managed and natural soils: result from a meta‐analysis (data after[140]). No‐till farming can slow soil erosion and pollution runoff, benefiting aquatic ecosystems, improving agronomic productivity, and achieving food security[7,69,70,[127][128][129][130]200,202,214]. No‐till farming, however, may not suffice to properly protect the soil when other practices are not implemented alongside; for example, cover crops or appropriate rotation schedules, or when it is accompanied by the use of high amounts of agrochemicals[215,216]. ...
... Soil erosion rate for managed and natural soils: result from a meta-analysis (data after[140]). No-till farming can slow soil erosion and pollution runoff, benefiting aquatic ecosystems, improving agronomic productivity, and achieving food security[7,69,70,[127][128][129][130]200,202,214]. No-till farming, however, may not suffice to properly protect the soil when other practices are not implemented alongside; for example, cover crops or appropriate rotation schedules, or when it is accompanied by the use of high amounts of agrochemicals[215,216]. ...
Article
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Soil health, along with water supply, is the most valuable resource for humans, as human life depends on the soil’s generosity. Soil degradation, therefore, poses a threat to food security, as it reduces yield, forces farmers to use more inputs, and may eventually lead to soil abandonment. Unfortunately, the importance of preserving soil health appears to be overlooked by policy makers. In this paper, I first briefly introduce the present situation concerning agricultural production, natural resources, soil degradation, land use and the challenge ahead, to show how these issues are strictly interwoven. Then, I define soil degradation and present a review of its typologies and estimates at a global level. I discuss the importance of preserving soil capital, and its relationship to human civilization and food security. Trends concerning the availability of arable agricultural land, different scenarios, and their limitations, are analyzed and discussed. The possible relation between an increase in a country’s GNP, population and future availability of arable land is also analyzed, using the World Bank’s database. I argue that because of the many sources of uncertainty in the data, and the high risks at stake, a precautionary approach should be adopted when drawing scenarios. The paper ends with a discussion on the key role of preserving soil organic matter, and the need to adopt more sustainable agricultural practices. I also argue that both our relation with nature and natural resources and our lifestyle need to be reconsidered.
... Meeting these future needs, especially if grain crops continue to be used as a source of bioenergy, will require an increase in agricultural productivity even greater than that achieved during the Green Revolution [21]. While much of the world's agriculture continues to be highly productive [22], it is unlikely that the required increase will be met using current policies and practices [23][24][25][26][27][28][29]. ...
... Perennial plants generally exhibit a much longer period of photosynthetic activity than annuals each year, as they often initiate growth rapidly in the spring and provide complete soil coverage many weeks earlier and maintain it longer into the fall. This dramatic difference can be observed in the corn belt region of the U.S. in the spring and after harvest when comparing agricultural lands planted to corn or soybeans to lands covered in perennial vegetation [29]. In addition to a longer time to convert solar energy into plant biomass, their more extensive yearly leaf canopy, litter layer, deeper root systems, and dormant vegetation limits soil loss from water runoff, raindrop splash, and wind, while also allowing for improved infiltration of water into soils [89][90][91]. ...
... Jackson and co-workers at the Land Institute in Salina, Kansas, USA have been examining and enhancing the potential of perennial grains, legumes, and other forbs adapted to prairie regions for a more sustainable replacement of annual crops. They have initiated breeding programs for a number of species, including perennial wheat, rye (Secale sp.), sorghum (Sorghum sp.), and others [29,95,96,98]. Jackson's concepts, referred to as Natural Systems Agriculture [129], include the development of an agricultural system that relies on the ecological benefits of diverse natural ecosystems, with the long-term aim of little or no sacrifice in food production. ...
Article
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J. Russell Smith (1874–1966), a professor of geography at Columbia University, witnessed the devastation of soil erosion during his extensive travels. He first published his landmark text, Tree Crops, A Permanent Agriculture in 1929, in which he described the value of tree crops for producing food and animal feed on sloping, marginal, and rocky soils as a sustainable alternative to annual crop agriculture less suited to these lands. A cornerstone of his thesis was using wide germplasm collection and plant breeding to improve this largely underutilized and genetically unexploited group of plants to develop locally adapted, high-yielding cultivars for the many climatic zones of North America. Smith proposed an establishment of “Institutes of Mountain Agriculture” to undertake this work. For a variety of reasons, though, his ideas were not implemented to any great degree. However, our growing population’s increasing demands on natural resources and the associated environmental degradation necessitate that Smith’s ideas be revisited. In this review, his concepts, supported by modern scientific understanding and advances, are discussed and expanded upon to emphasize their largely overlooked potential to enhance world food and energy security and environmental sustainability. The discussion leads us to propose that his “institutes” be established worldwide and with an expanded scope of work.
... In hilly or marginal lands, such crops cause severe soil erosion and degradation, and produce low yields (Wagoner 1989;Cox et al. 2006). Consequently, a growing number of human population faces food insecurity (Glover 2005). ...
... The concept in perennial grain-cropping systems is that they will function similarly to the natural ecosystems displaced by agriculture (Glover 2005;Glover et al. 2007). Whereas in annual plants a large part of their energy is directed to seed production, perennials spend a large portion of their energy on developing vigorous root systems. ...
Chapter
This chapter reviews the main farming practices related with soil organic carbon (SOC) sequestration in croplands, aimed, simultaneously, at improving soil quality and health, and reducing net emission of carbon dioxide into the atmosphere. The reviewed practices include conservation tillage, reduced tillage, no tillage, crop re­sidues management, manuring and fertilizing, and cover cropping. In addition, this manuscript addresses prospects for future development by means of agroforestry, biochar application, and perennial grain crops, aimed at maintaining sustainability of agroecosystems, restoring degraded croplands, and increasing the SOC sink capacity. The data collected supports the conclusion that taking into consideration the prevailing physical conditions, wise integration of various conservation practices may increase the ability of croplands in sequestering SOC while maintaining ecosystem services and enhancing agronomic production. KeywordsAgro forestry-Brochar-C-sequestration-Compost-Cover crops-Crop productivity-Greenhouse gaseous emission-Land reclamation-Off-site water pollution-Soil erosion control
... It should be noted, however, that this form of no-till still requires surface disking of the soil during some seasons, which some researchers argue reduces no-till's ability to reduce soil erosion (Triplett and Dick 2008 ) . In Salina, Kansas, researchers at the Land Institute are hybridizing annual grain crops with perennial varieties, in the hopes of creating a prairie-like, perennial grain agriculture (Soule and Piper 1992 ; Cox et al. 2005 Cox et al. , 2006 Glover 2005 ) . The vision of the Land Institute is to develop a permanent prairie agriculture within the next 25 years that is much less reliant on fossil fuels than current monoculture farming. ...
... The vision of the Land Institute is to develop a permanent prairie agriculture within the next 25 years that is much less reliant on fossil fuels than current monoculture farming. The aim is to sustainably produce grain crops year after year while minimizing both soil erosion and water contamination without heavy reliance on synthetic fertilizers or pesticides (Glover 2005 ; Cox et al. 2010 ) . Innovative research like this holds the promise of balancing the need to conserve soil while maintaining water quality and reducing human and environmental exposure to potentially harmful substances, though major advancements in grain yields will be necessary for perennial grain agriculture to be a viable option for farmers. ...
... It should be noted, however, that this form of no-till still requires surface disking of the soil during some seasons, which some researchers argue reduces no-till's ability to reduce soil erosion (Triplett and Dick 2008 ) . In Salina, Kansas, researchers at the Land Institute are hybridizing annual grain crops with perennial varieties, in the hopes of creating a prairie-like, perennial grain agriculture (Soule and Piper 1992 ; Cox et al. 2005 Cox et al. , 2006 Glover 2005 ) . The vision of the Land Institute is to develop a permanent prairie agriculture within the next 25 years that is much less reliant on fossil fuels than current monoculture farming. ...
... The vision of the Land Institute is to develop a permanent prairie agriculture within the next 25 years that is much less reliant on fossil fuels than current monoculture farming. The aim is to sustainably produce grain crops year after year while minimizing both soil erosion and water contamination without heavy reliance on synthetic fertilizers or pesticides (Glover 2005 ; Cox et al. 2010 ) . Innovative research like this holds the promise of balancing the need to conserve soil while maintaining water quality and reducing human and environmental exposure to potentially harmful substances, though major advancements in grain yields will be necessary for perennial grain agriculture to be a viable option for farmers. ...
Article
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No-till farming is a form of conservation tillage in which crops are seeded directly into the soil through previous crop residues, most commonly managing weeds using broad-spectrum herbicides and increasingly, transgenic herbicide-resistant crop varieties. Today, nearly a quarter of US cropland is farmed using no-tillage methods, a phenomenon which has been repeatedly described as one of the greatest agricultural revolutions of modern times. No-till advocates promote this method for its ability to reduce soil erosion, sequester soil carbon, reduce agricultural runoff, and improve farmland wildlife habitat, all while maintaining or even improving crop yields. Problems of water quality and contamination, as well as newly emerging problems associated with herbicide-resistant weeds, however, exist for no-till. This article reviews current literature on specific problems related to no-till agriculture, including soil and water impacts, soil carbon sequestration and ­greenhouse gases, and herbicide-resistant weeds; as well as the potential future of no-till farming and alternative no-till strategies that may address these problems.
... This has resulted in generally low levels of lucerne adoption in south-western Australia. Poor seedling vigour in many perennials is often attributed to the supposed large proportion of resources allocated by perennials to roots rather than shoots during early growth (DeHaan et al. 2005; Glover 2005). Evidence supporting this hypothesis for lucerne is equivocal. ...
... Difficulties associated with lucerne establishment and early growth in south-western Australia have focussed attention on the use of other perennial species to prevent the spread of dryland salinity. In particular, perennial cereal crops could be attractive, as they would fit easily into current farming systems (DeHaan et al. 2005; Glover 2005; Cox et al. 2006; Bell et al. 2008). Research into perennial wheat has been ongoing in the USA (Suneson et al. 1963; Cox et al. 2006; Glover et al. 2010) for many years, in an attempt to improve its grain yield. ...
Article
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Perennial plants such as lucerne are now widely acknowledged as one means of controlling the expansion of dryland salinity in southern Australia. However, their inclusion in farming systems is limited by poor seedling vigour, thought to be associated with greater allocation of biomass to perennating organs in roots, and poor adaptation to some soils and climatic conditions in south-western Australia. For this reason, interest in other perennial options such as perennial wheat is increasing. In this research we compared early (29-day) seedling growth and root : shoot ratios for annual and perennial medics (Medicago truncatula and M. sativa), and for annual and perennial wheat (Triticum aestivum and Triticum × Agropyron cross). For the medics, the annual reached the 6-leaf stage after 29 days and produced more root and shoot biomass than lucerne (4-leaf stage after 29 days), but there was no difference in root : shoot ratio or depth of root growth. For wheat, there were no differences in root growth, shoot growth, or root : shoot ratio between the annual and perennial lines (Zadoks growth stages 23 and 21, respectively, after 29 days). The poor competitive performance of M. sativa seedlings relative to M. truncatula was not due to changed allocation of biomass to shoots, but was related more to seed size (2.7 and 5.0 mg, respectively). This does not seem to occur to the same extent in perennial wheat lines, suggesting that their seedling performance may be more competitive.
... Provenza, 2008, p. E277 Current trends of deterioration and depletion of agricultural soils and irrigation sources threaten the long-term ability of agriculture to provide adequate food, fiber, and fuel to human society. To paraphrase Glover (2005;Glover and Reganold, 2010), it is both necessary and possible to restore ecosystem function to agricultural systems. This recognition must guide society's decisions regarding how to practice agriculture and manage ecologically restored land. ...
... Harvesting native or introduced grass biomass may provide energy in the North American Great Plains (Venuto and Daniel, 2010). Successful perennial grain breeding could revolutionize grain production (Glover, 2005). Integration of crop and livestock production can decrease soil erosion, reduce N fertilization, decrease unsustainable water use, improve aggregate soil stability, increase soil organic carbon, and increase soil microbial biomass compared with annual crops (Allen et al., 2008;Kirschenmann, 2007) in addition to addressing concerns associated with concentrated livestock production (Russelle et al., 2007). ...
... The development of herbaceous perennial grains for human consumption would reduce the agricultural impacts outlined in the MEA report. Crop species currently being developed include wheat, rice, corn, sorghum, sunflower (oil crops), and legumes (Moffat 1996, Pimm 1997, Glover 2005. Although decidedly controversial and still in the toddler stage, the development of perennial grains suitable for agriculture is well underway and prospects are excellent (Scheinhost 2001, Cox et al. 2002ab, DeHaan 2005. ...
Article
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Summary Pathogen reproduction tends to be host-frequency dependent, so that disease may be more problematic when particular crop species or genotypes are very common. Nonetheless, production agriculture is dominated by extensive monocultures. This is due partly to artifacts of agricultural policy and decision-making, but partly also to the real challenges of understanding and manipulating the ecological genomics of a single crop genotype, not to mention multiple species and genotypes. So there are trade-offs in investing agricultural research in many versus only a few agricultural species. Agricultural diseases may emerge or re-emerge for a number of reasons, including new pathogen introductions, new adaptation of pathogens to previously effective resistance genes, new types of host homogeneity (such as the widespread deployment of Texas male sterile cytoplasm in maize), trading policies that increase the economic impact of uncommon infections, and changes in the abiotic environment. Technological abilities in ecological genomics that are needed to support management of emerging and long-term disease include the ability to manipulate disease resistance genes in crops, the ability to devise crop plant communities at multiple spatial scales that are optimal for a range of agronomic traits, the ability to manipulate microbial communities for disease suppressive characteristics, and the ability to minimize undesired impacts on ecosystems surrounding agricultural systems. The construction of crop variety mixtures is an example of a technology that draws heavily on ecological ideas
... In addition, alternative crops with improved efficiency of fertilizer use and reduced reliance on pesticides would improve the sustainability of our agricultural systems 3 . Benefits of protection of soil from erosion, reduced leaching of water and nutrients, and additional forage for livestock could also be provided by perennial grain crops 2,4,5 . Exploring the wild native flora provides an exciting and substantial opportunity to identify species with potential as alternative grain crops for the future 6 . ...
Article
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Many agricultural systems around the world are challenged by declining soil resources, a dry climate and increases in input costs. The cultivation of plants that are better adapted than current crop species to nutrient poor soils, a dry climate and low-input agricultural systems would aid the continued profitability and environmental sustainability of agricultural systems. This paper examines herbaceous native Australian legumes for their capacity to be developed as grain crops adapted to dry environments. The 14 genera that contain herbaceous species are Canavalia, Crotalaria, Cullen, Desmodium, Glycine, Glycyrrhiza, Hardenbergia, Indigofera, Kennedia, Lotus, Rhynchosia, Swainsona, Trigonella and Vigna. A number of these genera (e.g., Glycine, Crotalaria, Trigonella and Vigna) include already cultivated exotic grain legumes. Species were evaluated based on the extent to which their natural distribution corresponded to arid and semi-arid climatic regions, as well as the existing information on traits related to harvestability (uniformity of ripening, propensity to retain pod, pod shattering and growth habit), grain qualities (seed size, chemistry, color and the absence of toxins) and fecundity. Published data on seed yield were rare, and for many other traits information was limited. The Australian species of Vigna, Canavalia and Desmodium mainly have tropical distributions and were considered poorly suited for semi-arid temperate cropping systems. Of the remaining genera Glycyrrhiza and Crotalaria species showed many suitable traits, including an erect growth habit, a low propensity to shatter, flowers and fruits borne at the end of branches and moderate to large seeds (5 and 38 mg, respectively). The species for which sufficient information was available that were considered highest priority for further investigation were Glycine canescens, Cullen tenax, Swainsona canescens, Swainsona colutoides, Trigonella suavissima, Kennedia prorepens, Glycyrrhiza acanthocarpa, Crotalaria cunninghamii and Rhynchosia minima.
... The replacement of annual with perennial grain crops could exacerbate the demand for food by the growing global population (see responses within Glover, 2005), where malnutrition affects about two thirds of the world population (WHO, 2000;FAO, 2009). However, worldwide 1,450 M ha of cropland have been abandoned (Field et al., 2008) and 910 M ha are considered to be degraded or marginal land for cultivation (FAO, 2000), a substantial amount given the estimated total 1400-1570 M ha of arable land worldwide (FAO, 2000(FAO, , 2009. ...
Article
Annual grain crops are planted on about 70% of the world's cropland and provide 80% of the world's food. Currently annual grains dominate grain production. Perennial grains offer many important opportunities to produce grains in a more environmentally, economically, and energetically sound manner. Thus, major research efforts are needed to develop perennial grains to help feed the growing and malnourished world population. These grains would also aid in diversifying agriculture.
... 17, 2019; systems might meet nutritional needs while also improving ecological sustainability. In recent years attention has focused in part on the possible development of perennial, herbaceous crops [11], [13], [14], [64] . Expanding development of species such as wild, perennial legumes, into an agroforestry system offers opportunities to enhance food production and possibly reduce the risk of nutrient deficiencies [6], [7], [65], [66] . ...
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Malnutrition is a global public health concern and identifying mechanisms to elevate the nutrient output of crops may minimize nutrient deficiencies. Perennial grains within an agroforestry context offers one solution. The development and integration of perennial crops for food has critically influenced dialogue on the ecological intensification of agriculture and agroforestry. However, the nutrient compositions of wild, perennial, herbaceous species, such as those related to the common bean (Phaseolus vulgaris) are not well known. In this study, seed amino acid and ion concentrations of perennial and annual Phaseolus species were quantified using ionomics and mass spectrometry. No statistical difference was observed for Zn, toxic ions (e.g. As) or essential amino acid concentrations (except threonine) between perennial and annual Phaseolus species. However, differences were observed for some nutritionally important ions among and within lifespan groups. Ca, Cu, Fe, Mg, Mn, and P concentrations were higher in annual species. Intraspecific variability in ion concentrations and amino acids was observed within species; further, ion concentrations and amino acids differ among annual species and among perennial species. Ion and amino acid concentration appear to be largely independent of each other. These results suggest variability in ion and amino acid concentrations exist in nature. As new crop candidates are considered for ecological services, nutritional quality should be optimized to maximize nutrient output of sustainable food crops.
... Since the '50 s of the last century, ''Green Revolution'' technologies have dramatically enhanced crop yields reducing simultaneously other ecosystem services, such as biodiversity (Smith and Gregory 2013;Kassam and Friedrich 2012) and carbon stock (West et al. 2010). Agricultural systems based on annual crops have been considered amongst the main causes of soil degradation worldwide (Glover 2005) and the source of a significant amount of greenhouse gases (GHGs) (Smith et al. 2014); in addition, they are threatened by climate change that strongly impacts agricultural yields (Smith 2008). Therefore, the adoption of more sustainable practices could either decrease the impacts of agriculture on the climate and enhance agriculture resilience. ...
Article
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Perennial crops are emerging as an effective strategy for adapting to climate change, but also for mitigating net greenhouse gas emissions from agriculture. This study aims to investigate the agronomic and physiological performance of selected perennial wheat genotypes derived from crosses between Triticum aestivum L. and Thinopyrum spp to evaluate if they could give a contribute both to face climate changes and to restore soil health. Four perennial wheat genotypes were grown in Central Italy and compared in terms of agronomic traits, root development (biomass and length) and ecophysiological parameters with an annual common wheat cultivar. Plants were, on average, taller in perennial wheat genotypes than in annual wheat as well as the number of tillers per plant (+ 49%), root length (+ 43%) and root biomass (+ 31%) in both years, whereas, perennial wheat kernels were smaller (− 15%). Post harvest regrowth occurred in different amounts in all perennial wheat genotypes. In terms of the ecophysiological response, perennial wheat lines revealed higher soil respiration and lower stomatal conductance than annual wheat. On the contrary, transpiration rate, water use efficiency and photosynthesis were higher in annual genotype than in perennial ones. The environmental benefits of adopting perennial grains are discussed together with suggestions on optimal field management and future breeding strategies.
... The native prairies replaced by modern agriculture were diverse mixtures of predominantly perennial species and they lacked these environmental problems, though they produced no harvestable grain (Jackson, 2002). Perennial grain polycultures, i.e., mixtures of herbaceous plants harvested for seed, have been proposed as food production systems with the ecological advantages of perennial cover and diversity (Glover, 2005). Development of perennial grain polycultures with adequate yield will require breeding of perennial grain crops (Cox et al., 2006;DeHaan et al., 2005;Sacks et al., 2003) and agroecological studies to develop best management practices Crews, 2005). ...
Article
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Diversity, productivity, and stability in perennial polycultures used for grain, forage, and biomass production
... Annual crops require extensive preparation of land at great expenditures of energy. Cultivation of annuals is usually more productive than that of perennials, but it can lead to greater soil erosion, lower water storage in the soil and subsoil, poorer soil carbon balance, greater nutrient leeching from soil, poorer weed suppression, and negative effects on soil microbiomes (Robertson et al. 2000;Crews 2005;Glover 2005;Tilman et al. 2006). In locations where the negative consequences of cultivation of annual crops outweigh their yield advantage, the cultivation and breeding of perennial forms of crops traditionally grown as annual may be advantageous. ...
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Key message: A locus for perennial growth was mapped on Lophopyrum elongatum chromosome arm 4ES and introgressed into the wheat genome. Evidence was obtained that in addition to chromosome 4E, other L. elongatum chromosomes control perennial growth. Monocarpy versus polycarpy is one of the fundamental developmental dichotomies in flowering plants. Advances in the understanding of the genetic basis of this dichotomy are important for basic biological reasons and practically for genetic manipulation of growth development in economically important plants. Nine wheat introgression lines (ILs) harboring germplasm of the Lophopyrum elongatum genome present in the octoploid amphiploid Triticum aestivum cv. Chinese Spring (subgenomes AABBDD) × L. elongatum (genomes EE) were selected from a population of ILs developed earlier. These ILs were employed here in genomic analyses of post-sexual cycle regrowth (PSCR), which is a component of polycarpy in caespitose L. elongatum. Analyses of disomic substitution (DS) lines confirmed that L. elongatum chromosome 4E confers PSCR on wheat. The gene was mapped into a short distal region of L. elongatum arm 4ES and was tentatively named Pscr1. ILs harboring recombined chromosomes with 4ES segments, including Pscr1, incorporated into the distal part of the 4DS chromosome arm were identified. Based on the location, Pscr1 is not orthologous with the rice rhizome-development gene Rhz2 located on rice chromosome Os3, which is homoeologous with chromosome 4E, but it may correspond to the Teosinte branched1 (TB1) gene, which is located in the introgressed region in the L. elongatum and Ae. tauschii genomes. A hexaploid IL harboring a large portion of the E-genome but devoid of chromosome 4E also expressed PSCR, which provided evidence that perennial growth is controlled by genes on other L. elongatum chromosomes in addition to 4E.
... In perennial wheatgrass, natural selection has been acting on species in competitive prairie ecosystems where N is limited. Deep root systems and longer photosynthetic duration may indicate that perennials are more efficient at capturing and using N (Glover 2005;Cox et al. 2006). In addition, there is a significant amount of variation among perennial species and varieties. ...
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... Producing cellulosic-derived ethanol from perennial biomass crops has the potential to significantly improve water quality (Simpson et al., 2008), provide more net energy and reduce GHG emissions (McLaughlin and Walsh, 1998). This is feasible because perennial biomass crops (1) provide year-round ground cover that intercepts rain and reduces erosion, (2) develop plant root systems at greater soil depths and more extensively than annual crops-thus stabilizing the soil, and (3) capture a greater quantity of nutrients, reduce leaching volume, improve water infiltration, reduce water runoff, and increase soil organic matter (McLaughlin and Walsh, 1998;Mann and Tolbert, 2000;Lewandowski et al., 2003;Dinnes, 2004;Glover, 2004;Cox et al., 2006). Perennial feedstock may also require less fertilizer and pesticide inputs than current row crops (Lewandowski et al., 2003;Crews, 2005;Perlack et al., 2005). ...
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