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Low-Carbon Agriculture in South America to Mitigate Global Climate Change and Advance Food Security
... This is because the trees give natural shading to the animals Giro et al., 2019;Barreto et al., 2020;Bosi et al., 2020). These systems also provide an opportunity to recover degraded pasture regions and incorporate the principles of conservation agriculture while reducing the intensity of greenhouse gas emissions (Sá et al., 2017). ...
... Successful initiatives in the implementation of iCLF production systems have been reported in the Americas (Joele et al., 2017;Moneeb et al., 2019;Huertas et al., 2021;Polidoro et al., 2021), Europe (Garrido et al., 2017), and Africa (Schwartz, 2014). This indicates great potential for expanding iCLF systems in tropical (Sá et al., 2017) as well as temperate and Mediterranean regions (Hidalgo-Galvez et al., 2022). However, areas with integrated systems require more efficient agricultural monitoring. ...
... Agrosilvopastoral systems are characterized by an increased input of organic material such as leaf litter, which can provide a microclimate with greater soil moisture (Nair et al., 2008). In addition, the deposition of plant residues and the accumulation of organic material at different stages of decomposition on the soil surface can reduce evapotranspiration and increase infiltration (Sá et al., 2017). In iCLF systems, there is less soil disturbance and more aggregate stability (Salton et al., 2014), which often results in a greater capacity for water retention and a reduced soil temperature. ...
Better livestock practices are needed to enable more efficient and sustainable food production. Integrated crop-livestock-forest (iCLF) production systems stand out among these. However, iCLF systems have not yet been monitored remotely using infrared thermography (IRT). Crewed overflights were conducted every 21 days for 14 months in Sao Carlos, Brazil (21◦58′30″S, 47◦51′07″W, 854 m AMSL) to (i) evaluate the efficiency of remote thermographic sensing of pastures for beef cattle and (ii) study the surface temperatures of pastures in monoculture/full sun (FS system) or iCLF (iCLF system). There was a significant correlation between air temperatures recorded at 1.5 m from the ground by automated meteorological stations and temperatures recorded using IRT, with the highest correlation coefficients observed in FS at 12:00 PM (r = 0.89; P = 0.0013) and in iCLF between
10:00 AM and 11:00 AM (r = 0.77; P = 0.0142). The surface and air temperatures did not differ significantly in FS (2:00 PM–4:00 PM) and iCLF (8:00 AM–6:00 PM; P > 0.05). In all seasons, IRT revealed higher thermal classes more frequently in FS. Heat maps showed notable differences between the production systems, including two heterogeneous thermal zones. Circumscribed areas of varying sizes with higher surface temperatures (>35.0◦C) were also observed in spots (FS) or parallel bands in the east–west direction (iCLF). These areas had no trees and/or less vegetation cover. Infrared thermography remote sensing in crewed overflights ran concurrently with temperature readings from on-site meteorological stations. This enabled the precise identification of thermographic differences between pastures in monoculture and integrated systems, with the definition of heat islands and comfort zones. This study provides insights into the novel application of IRT for microclimatic assessments of livestock pastures, which can aid in decision-making to improve the welfare of free-range animals.
... The great social and economic importance of the cultivation of YM in the region has driven the development of different studies that generated important technical advances for its production related to yield, product quality, certification and marketing [10][11][12][13][14]. Nevertheless, there is no report on the issues related to the environmental impact of the YM supply chain, and it is a well-known fact that the South American continent has long been facing the onset of soil depletion and increased CO2eq. emissions [15,16]. YM production area is located within the Atlantic Forest ecosystem known as Mata Atlántica, where almost 85% of its coverage has disappeared due to deforestation [17,18], and the change in land use has generated loss of biodiversity [19,20] and edaphic and water degradation [21]. ...
... emissions. Ultimately, it is necessary to emphasize the importance of the transition of agricultural systems towards low-carbon strategies that can counter increasing trends in emissions from land use in South America [16]. ...
Yerba mate (YM) is an important crop derived from the cultivation of the native tree Ilex paraguariensis in northeastern Argentina, used for the preparation of mate infusion, which is widely consumed in South America. This study aimed at assessing the environmental impact, namely of CO2 equivalent (CO2eq.) emissions, of the YM value chain while identifying environmental hotspots along the production chain, from nursery up to transport. A cradle-to-wholesale approach was carried out, considering as the main functional unit 1 kg of commercial YM produced in Misiones Province and transported to Buenos Aires, the largest YM market in the world. Primary data were gathered from representative nurseries and plantations of the region; processing and packaging data were collected from a local cooperative, while the assessment of the impact due to truck transport was performed considering a distance of 1200 km from Buenos Aires. All the processes were analyzed using LCA methodology following the guidelines outlined in the ISO 14044 regulation (EN ISO 14044); the GaBi software (Sphera Solution, Inc., Chicago, IL, USA), updated to version 10.7.21.8, was used for process modeling, while the CML 2001 calculation method, updated as of the latest release in August 2016, was used to calculate the impacts. The results (1.24 kg CO2eq./kg. YM produced in Misiones and transported to Buenos Aires) show that the cultivation phase of YM has very little impact, while most of the emissions are related to the drying phase and the subsequent transportation from the production area to Buenos Aires.
... Farmers till the soil to prepare the seedbed, control weeds, lose compacted topsoil, or incorporate fertilizers. However, tillage and other soil disturbing activities can cause various problems such as creating highly compacted wheel tracks, soil erosion, topsoil re-compaction, germination of buried weed seeds, an increase of the CO 2 emission from fuel, degradation of SOC, and destroying the habitat of soil macrofauna e.g., earthworms (de Moraes Sá et al., 2017;Vakali et al., 2011). For these reasons, RA is aiming for minimizing soil disturbance to maintain soil health. ...
... In arable farms, organic manure is mostly imported from outside the farm, which partially contributes to CO 2 emissions during transportation. In South-America, integrating crop-livestock systems was shown to offset farm emissions by 26% (de Moraes Sá et al., 2017). Under the European conditions with high intensifi cation, it was suggested that closer integration of crop and livestock fi elds can increase resources recycling and reduce the dependency on external inputs (Peyraud et al., 2014). ...
The “Healthy Soil - Healthy Future” initiative of Agrifirm’s innovation corridor Regenerative Agriculture aims to provide a comprehensive understanding of Regenerative Agriculture (RA), its objectives, practices and benefits, with a focus on the Dutch context.
... In managed ecosystems, anthropogenic factors are also important drivers, especially in increasing greenhouse gas (GHG) emissions by the retrieval and burning of fossil fuels, land-use change, and large-scale soil mobilization 8, 9 . Thus, one priority is to nd alternatives to reverse the direction of excess C ow by using plants to capture atmospheric CO 2 and the soils to sequester it for the long term [10][11][12] . The core objectives of this proposal are to stop the degradation processes that lead to soil C loss and adopt practices that promote C accrual 13,14 . ...
... The present study involves the Americas region, with an agricultural area of about 1.11 billion hectares 23 , as a case study of the potential of C sequestration due to the introduction and adoption of BMPs in agricultural systems. Conservation tillage, pasture reclamation, and integrated agricultural systems are management strategies already employed by farmers in the continent 10,24,25 . Therefore, by using data available in the literature, this article rst attempts to estimate the potential for C sequestration in the soil by the widespread use of BMPs in the agricultural sector and estimates the area required to mitigate agricultural GHG. ...
Soil represents Earth's largest terrestrial reservoir of carbon (C) and is an important sink of C from the atmosphere. It remains unclear to which extent the inclusion of best management practices (BMPs) can contribute to increasing soil C sequestration in large-scale agrosystems. Solving the lack of soil C references can also allow the implementation of the C market, envisioned by the Paris Agreement. This study brings an overview of thousands of research articles and reveals that upscaling BMPs over 30% of the agricultural area (334 Mha) of the Americas would promote a soil C sequestration of 13.3 (± 7.30) Pg CO 2 eq in 20 years, offsetting ~ 39% of agricultural emissions in the same period. These results suggest that BMPs have great potential for C removal from the atmosphere and represent a positive impact in terms of climate change mitigation and adaptation, combatting land degradation, and promoting food security.
... Another study in South America examined the possibilities for lowcarbon agriculture to help reduce climate change and promote food security. South America accounts for 31.3% of global annual greenhouse gas emissions from land use and land-use change, according to the study (Sá et al., 2017a). Between 2016 and 2050, South America's potential as N.E.H. Chaher et al. ...
... The application of LCRF techniques to achieve high rice production efficiency, high yield, low carbon emissions, a high carbon sink, reduce pollution, and protect cultivated land are known as LCRF behaviors (Cao and Li, 2014;Chen et al., 2021). Similar to ecological farming and green production, these production behaviors can decrease damage to the environment and promote the sustainable development of the agriculture industry (Sá et al., 2017;Schoonhoven and Runhaar, 2018;Tan et al., 2022;Zhang et al., 2022a). As a branch of general low carbon farming, the major characteristics of LCRF are construction of a rice field farming system "that prioritizes increasing carbon sinks, decreases consumption, and focuses on reducing carbon emission and recycling" based on the principle of rice field ecosystem carbon cycling to promote low carbon and high yield rice production (Cao and Li, 2014;Chen et al., 2021). ...
Introduction
Rice production is the core component of the food security strategy in China, but it is also a major source of methane and nitrous oxide. Promoting low-carbon rice farming (LCRF) to increase the carbon sink, decrease carbon emissions, and achieve low-carbon, high-yield production is an inevitable “win-win” choice for achieving “double carbon” targets and guaranteeing national food security. This study contributes to the advancement of research on farmers’ adoption decisions and fills gaps in LCRF’s technical research on farmers’ decision-making behavior. The results also provide a basis for formulating policies to encourage LCRF and protect cultivated land.
Methods
This study conducted field research on 2,173 farming households in Jiangxi Province, a traditional agricultural province in China, and examined the effects of personal forces, local forces, and cultural forces on LCRF adoption behavior by introducing the distributed cognition theoretical framework based on a status quo analysis and employing the multivariate ordinal logistic model.
Results and discussion
The results of the study showed that: 1) the overall acceptance of LCRF behavior is currently not very high. In the 2173 questionnaires, the mean number of LCRF behavior items accepted by farmers was 3.10 items; 153 farmers did not adopt any LCRF behavior, and only 77 farmers adopted all LCRF behaviors. Most farmers (n = 535) adopted three LCRF behaviors. 2) In distributed cognition affecting LCRF behavior, acceptance was primarily affected by cultural forces, followed by local forces, while the effects of personal forces were limited. Therefore, it is recommended that training and promotion should be increased, policy subsidies should be increased, the land market should be improved, and LCRF demonstrations should be carried out to increase the acceptance of LCRF behavior among rice farmers.
... The frequency of citations has increased significantly over the last decade (2013-2023) and peaked in 2022 (113). Lal R's articles on factors affecting soil organic carbon sequestration in agro-ecosystems and the development of policies to reduce agricultural carbon emissions to ensure food security and mitigate climate change have been cited by scholars more frequently, and Lal R's [44][45][46] articles provide new ideas and methods for related researchers. The growing number of scholars citing this author's work on agricultural carbon emissions research indicates that he has made a significant contribution to the field. ...
As climate change intensifies and countries actively pursue carbon peaking and carbon neutrality targets, agriculture has emerged as a significant source of carbon emissions. A comprehensive analysis of global agricultural carbon emission research can enhance the agricultural environment and achieve a mutually beneficial outcome for environmental protection and economic development. Despite the evolution of research domains and methodologies, the global context remains closely connected to the current state of the discipline. Drawing on the Web of Science core collection, this paper develops a knowledge network framework, examines the current status and hotspots of agricultural carbon emissions, forecasts future development trends, and analyzes the findings using CiteSpace visualization software. The findings indicate that the number of papers on agricultural carbon emissions has been increasing annually, with minor fluctuations; time series analysis and sustainable development have emerged as the current focal points, and relevant institutions are collaborating increasingly closely. However, cooperation among scholars requires further enhancement. Countries such as China, the United States, and Germany are the primary nations for paper publication. The hotspot analysis reveals a high frequency of keywords such as greenhouse gas emissions and climate change, indicating that research on agricultural carbon emissions has matured and the emphasis has shifted from accounting to management. This paper develops a domain knowledge framework to assist readers in understanding agricultural carbon emission patterns and provide resources for further research. Follow-up studies should enhance both comprehensiveness and breadth, promote interdisciplinary cooperation, provide a scientific foundation for policymakers, and outline future research directions.
... Agriculture is being intensified to increase production, primarily with monocultures that are heavily dependent on increased chemical inputs, such as pesticides and fertilisers (McArthur and McCord, 2017). To achieve economic returns for farmers, but with stability in long-term production and little negative influence on the environment, we must establish sustainable agriculture practises based on conservationist practises (de Moraes Sa et al. 2017). The most limiting element in ecosystems and a necessary component of all living creatures is nitrogen. ...
Nitrogen is an essential nutrient for plants and is often a limiting factor in crop growth. Large quantities of fertiliser are often applied to crops which is an energy-consuming, expensive and pollution producing procedure from production to application. Biological nitrogen fixation is a solution to reduce nitrogen-related problems in agriculture. Biological nitrogen fixation, the reduction of dinitrogen (N2) to ammonia, is an essential reaction in the global nitrogen cycle. Many legumes have evolved to establish a symbiosis with nitrogen-fixing soil-bacteria collectively known as Rhizobia. More than 98 species of symbiotic nitrogen-fixing rhizobia exist in 14 taxa in association with legumes.Keywords: Symbiotic nitrogen fixation, biological N fixation, legumes213
... It reduces greenhouse gas emissions by sequestering carbon dioxide from the environment. It involves increasing soil, plant, and agricultural product carbon storage (de Moraes Sá et al., 2017). Carbon farming facts: Carbon capture: Carbon farming captures and stores CO 2 to fight climate change. ...
Carbon farming refers to sequestering and storing carbon and reducing
greenhouse gas emissions at the farm level. It is encompassing a range
of practices in agriculture, forestry, and livestock management aimed
at sequestering carbon dioxide from the atmosphere and mitigating
climate change. In agriculture, techniques, such as cover cropping,
rotational grazing, and no-till farming promote soil health and
enhance carbon storage. Similarly, afforestation and reforestation
efforts in forestry contribute to carbon sequestration through tree
growth and forest management. Livestock management practices
like rotational grazing and improved feed efficiency also play a role
in reducing emissions and enhancing carbon storage. The benefits
of carbon farming include climate change mitigation, improved soil
health, water conservation, and biodiversity conservation. However,
challenges related to knowledge dissemination, financial barriers,
scaling up, and policy support must be addressed to ensure widespread
adoption and maximize the potential of carbon farming in addressingclimate change and promoting sustainability. Carbon farming in
agriculture offers the potential to mitigate climate change, enhance
soil health, improve water management, and promote sustainable
farming systems. By sequestering carbon and reducing greenhouse
gas emissions, agricultural practices can contribute to global efforts
in combating climate change while ensuring food security and
environmental sustainability.
... The emission of gases from soils is one of the most important features related to soil quality, crop production, and GHG (Button et al. 2022;Sá et al. 2017). Agricultural practices that reduce denitrification are crucial to maximize the plant N (nitrogen) uptake, and to reduce the emissions of NO (nitrogen monoxide) and N 2 O (nitrous oxide), which heavily contribute to global warming (Chen et al. 2022;Ouyang et al. 2018). ...
... Over the last decades, several long-term experiments demonstrated numerous benefits of NTS, including but not limited to enhanced crop yields, C-sequestration, and improvement of the overall soil quality, representing a significant tool to promote food security and climate change mitigation (Sá et al., 2017). The concept of soil resilience was introduced as a measure of C stock recoveries by land management after disturbance (Herrick and Wander, 1997;Seybold et al., 1999). ...
Land management systems that comprise the principles of conservation agriculture (CA) can lead to soil organic carbon (SOC) gains over time. Nonetheless, how fertilization regimes interfere with their performance in highly weathered soils is still uncertain. This study presents results on SOC storage, crop yield, and soil resilience from a long-term experiment in southern Brazil (Ponta Grossa – Paraná State) 26 years after its establishment in 1989 combining a gradient of soil disturbance through diverse soil management strategies with contrasting fertilization regimes. We hypothesized that preserving soil structure rebuilt over time through no-till system plays a significant role in SOC persistence and the fertilization regime can impact land management performance on soil resilience and crop yield. The experimental design was laid out as a split plot through completely randomized blocks. The main plots comprised the treatments related to soil management systems: 1) conventional plow-based tillage – CT; 2) minimum tillage (Chiselling replacing plowing) – MT; 3) no-till with one chisel plowing every three years – NTch; and 4) continuous no-till system – NTS. The sub-plots comprised full crop fertilization (FCF) for all crops and low crop fertilization (LCF) by suppressing K and P fertilization and maintaining N in broadcast application. SOC stocks significantly improved as the soil disturbance diminished, resulting in higher soil resilience indexes for NTS and NTch. Differences in SOC stocks between the contrasting treatments NTS and CT were higher under low fertilization, resulting in C and N sequestration rates of 1.14 and 0.14 Mg ha−1 year−1 under LCF compared to 0.77 and 0.08 Mg ha−1 yr−1 in FCF at the 0–100 cm layer. Such higher differences were induced by overall higher SOC stocks of CT when under FCF and higher SOC stocks in subsoil depths promoted by NTS when under LCF. High fertilization treatments produced cumulative yields 1.5 times higher for soybeans and 2.5 times higher for corn throughout the 26 years of the experiment. Labile C fractions extracted by hot water (HWEOC) and K-permanganate (POXC) were systematically increased as the disturbance diminished. Gains in labile fractions were promoted in deeper layers in lower disturbance treatments (NTch and NTS). We conclude that combining conservation agriculture principles ultimately defined the potential for SOC sequestration. The high soil resilience under the NTS in this research indicates a considerable potential to reverse the soil degradation and decline of the SOC and labile fractions by conversion to intensive NTS (high and diversified annual C input) associated with absence of soil disturbance.
... Earthworm microbiomes are an important biological driver of soil fertility with implications for climate resilience in cropping systems under global change. Such microbiomes help earthworms mineralize and mobilize essential plant nutrients from organic matter, thereby improving nutrient availability (Chauhan 2014;Bayu 2020;de Moraes Sá et al. 2017). ...
Background and aims
Agriculture is using litter inputs (such as straw) as an alternative to inorganic fertilization; however, little is known about how these inputs can alter the microbiome of our soils. Earthworms are major ecosystem engineers and play a critical role in decomposing litter in terrestrial ecosystems, assisted by their gut microbiomes. However, very little is known about how litter types and combinations, and their associated quality (labile vs recalcitrant), regulate the microbiome of earthworms.
Methods
Here, we conducted a 42-day microcosm experiment to investigate the influence of two litter (straw) types, with contrasting recalcitrance, and its combination in driving the microbiome associated with different earthworm compartments, including soils, casts and guts. In each compartment, samples were collected every 14 days, and the microbiome was measured by16S rRNA amplicon sequencing.
Results
We found that the labile peanut straw initially decreased bacterial richness with this effect being diluted with time. Litter quality and earthworm compartment independently and significantly affect the resultant bacterial community composition (P ≤ 0.01). Litter inputs also resulted in unique microbiomes, which differ across compartments, including soils, casts and guts.
Conclusion
Litter quality can result in contrasting soil and earthworms’ microbiomes in cropping fields, and these may act as indicators of management story with consequences for the conservation of soil microbiomes and fertility under litter fertilization.
... Among the soil nutrient fertilizers available, nitrogen (N) is the most expensive nutrient management strategy that accounts for a significant share of total production cost [19]. However, when applied to the soil, it can cause environmental damages since it is usually lost by leaching and volatilization [20]. In addition, nitrogen fertilizer manufacturing consumes much oil, which is a non-renewable energy source. ...
... Щоб зберегти стійкість природних екосистем і навколишнього середовища, а також забезпечити підвищення врожайності сільськогосподарських культур для вирішення майбутніх продовольчих проблем, потрібні нові екологічно обґрунтовані заходи для сільськогосподарської практики [5,6]. Все частіше озвучуються ідеї нової, «свіжої» зеленої революції (можливо, біологічної революції), яка повинна базуватися на меншій кількості інтенсивних витрат і меншому впливі на довкілля [7]. ...
... Integrated crop-livestock-forest systems combine the cultivation of crops, raising of livestock, and management of forested areas within a unified system. These different agricultural managements were all highlighted in "Brazil's Low Carbon Agriculture plan" as potential soil carbon sinks (Sá et al., 2017). ...
Tropical soils play a critical role in the global biogeochemical cycles and are essential for maintaining the Earth's carbon balance. Understanding the dynamics of dissolved organic matter (DOM) is paramount due to its implications for ecosystem functioning and nutrient cycling. This study comprehensively evaluated the origin, distribution, and composition of DOM and inorganic solutes in Brazilian tropical agricultural soils. Multiple analytical techniques were utilized to assess DOM from soil profiles (0-100 cm depth) across a spectrum of land uses, including a native Atlantic Forest, a degraded pasture, as well as intensive grazing, extensive grazing, and silvopastoral systems. Inorganic elements were quantified to assess the coupling between the organic and inorganic biogeochemical cycles. The dominance of C 4 carbon in topsoil layers suggested substantial contributions of organic matter from grasses to the soil organic matter pool. However, with increased depth, C 3 carbon inputs became more prominent, indicating the influence of forest vegetation that existed prior to the implementation of agricultural managements. DOM concentrations decreased with soil depth due to reduced carbon inputs, sorption to minerals, or oxidation. DOM composition did not show significant changes among different land use and managements. Lignin was identified as the primary contributor to oxidized DOM with increasing soil depth. The composition of DOM exhibited a shift from more aromatic and higher molecular weight compounds in topsoil layers to smaller, more aliphatic compounds in subsoil layers. Our key findings revealed that aliphatic compounds, particularly fatty acids, tend to accumulate in deeper soil layers. This phenomenon was consistent in pastures dominated by grasses but not in soils near treed vegetation. Overseeding (from C 3 plants) did not significantly impact DOM compositions, emphasizing the persistence of C 4 plants in these systems. The presence of inorganic elements in soil water extracts showed minimal impact on DOM dynamics, suggesting decoupled organic and inorganic biogeochemical cycles in tropical pasturelands.
... On the other hand, the purple and yellow clusters had terms such as agroforestry, ecosystem services, biodiversity, conservation, REDD, sustainable land use, and agroecosystem management activities which are essential in achieving the potential of CLFs as NBS to combat climate change and achieve SDGs (Gil et al. 2019;Mbow et al. 2014). Many studies have established enormous capabilities of CLFs as types of agroforestry in capturing excess atmospheric CO 2 , storing, and sequestrating it in plants and soils thereby enhancing ecosystem services, mitigating climate change, promoting food security, and SDGs at local national, regional, and global scales (Gil et al. 2016;Garrett et al. 2017;Viana et al. 2022;Sá et al. 2017;Gil et al. 2019;Mbow et al. 2014). ...
... A literature review of agricultural lowcarbon technology research shows that technology adoption and diffusion are impressive subjects in the field of low-carbon or green technology development (Shi & Lai, 2013). Generally speaking, the promotion of low-carbon technology in agriculture mainly focuses on two aspects, namely reducing greenhouse gas emissions in agricultural production (Newton et al., 2016) and increasing carbon sinks in agricultural ecology (Sa et al., 2017). Farmers' adoption of LCTs has attracted worldwide attention (Yang et al., 2022a). ...
The promotion of low-carbon technologies (LCTs) is an important way to promote agricultural carbon reduction and respond to climate change. In this study, the intentions to adopt LCTs of 528 planting farms was investigated by random sampling, and the structural equation model was used for analysis. The study confirmed that the model combining theory of planned behavior (TPB) and theory of ‘value-belief-norm’ (VBN) is appropriate in predicting the adoption intention of LCTs. Importantly, there were differences in the formation mechanism of adoption behavior between traditional farmers (with lower levels of education, less experience and focus on short-term interests) and elite farmers (with higher levels of education, more experience and focus on long-term interests). The impact of behavior attitude on intentions of LCTs was not tenable for traditional farmers, while the effect of perceived behavior control on behavior of LCTs was not tenable for elite farmers. Overall, this study confirms the importance of designing differentiated low-carbon technology promotion programs. In the future research, we will continue to pay attention to the differences of agricultural low-carbon technology adoption in different regions, hoping to provide some inspiration for agricultural managers.
... These results demonstrates that only sowing without disturbance is not enough to promote SOM accumulating in no-till, being also crucial to maintain the soil cover and, in particular, implement a crop rotation that allows a strategic combination of quantity, quality, and frequency of biomass-C additions (Sá et al., 2017). Recently, De Oliveira Ferreira et al. (2012) reported a minimum amount of biomass input of 3.21 Mg C ha -1 yr -1 (7.13 Mg ha -1 yr -1 of plant biomass) required to maintain SOM. ...
Soil organic matter (SOM) is a pivotal component for sustainable agriculture in any environment. SOM plays a crucial role in soil quality by providing positive effects on soil chemical, physical and biological properties besides increasing crop productivity. Furthermore, SOM is a component of the global carbon cycle, and changes in its content can mitigate or intensify the emission of greenhouse gases. High SOM content can ensure food security for a growing world population while reducing the adverse effects of climate change. Therefore, understanding SOM dynamics is decisive while creating strategies that enhance its accumulation and permanence in the soil. In general, these strategies should be based on increasing inputs and decreasing losses of SOM. Several natural (climate and soil) and anthropogenic (management practices) factors, in a dynamic interaction, drive the accumulation of SOM. The main climate factors are temperature and precipitation, which can be associated with net primary productivity and SOM decomposition rates. Soil factors are mainly texture, mineralogy, and aggregation, having the most effect on SOM stabilization processes. Finally, several management practices can be used as a strategy for SOM accumulation, including smart land use, organic amendments, biochar, mineral fertilization, liming, cover crops, and no-till. Worthwhile highlight that management practices can be changed and improved, contrary to climate and soil, whose characteristics are immutable in the short term. Thus, this chapter emphasized and discussed management practices with more emphasis.
... For example, agricultural practices such as conventional (deep-tillage) and conservation tillage (no-tillage or reduced-tillage) can alter soil microbial properties (Bünemann et al. 2006;Fierer et al. 2021). No-tillage management is crucial for enhancing soil nutrient storage and availability (de Moraes et al. 2017;Garland et al. 2018), aggregate stability (Bronick and Lal 2005), and the diversity and metabolic activities of microbial communities associated with soil aggregates (Hsiao et al. 2018;Tian et al. 2022). ...
Background and aims
Conservation tillage enhances soil aggregate function, —a key factor for promoting soil nutrient cycling and plant growth. However, there is a limited understanding of how tillage practices impact soil nutrients, enzymes and microbes distribution among different-sized aggregates, and their potential subsequent effects on other soil functions and processes.
Methods
We conducted a long-term experiment involving maize (Zea mays L.) cultivation in a semiarid farming region in Northwest China. Four tillages were implemented: no-tillage, minimal tillage, fold-tillage, and sub-tillage. Soil aggregates were categorized based on size: <0.25 mm (‘micro’), 0.25–2 mm (‘small’), and > 2 mm (‘macro’). We measured the nutrient contents, enzyme activity, enzymatic stoichiometry, and soil microbial community structure with each fraction, and assessed crop productivity.
Results
The no-tillage treatment increased soil C content, microbial biomass, and P and N availability within micro-aggregates and bulk soil. It also enhanced enzymatic activity related to C and P acquisition and the C: N enzymatic ratio but decreased the N: P enzymatic ratio in micro-aggregates. Notably, no-tillage promoted straw and root biomass and crop yield compared to conventional tillage. Microbial community structure differed under the different tillage regimes and among aggregate size fractions, particularly under conventional tillage, but the tillage system did not affect alpha diversity.
Conclusions
Our results highlight that long-term conservation tillage positively influenced soil aggregates by increasing carbon content and enzyme activity, thereby, reshaping the soil microbial community composition within aggregate size fractions in semiarid agroecosystems.
... Integrated systems have been gaining more and more space in agriculture due to the possibilities of adoption, benefits, and complexity identified through years of study, and estimates claim that Brazil will expand around 33 million hectares in integrated agricultural systems, livestock, and forestry areas by 2050 (Sá et al., 2017). The characteristic integrating agricultural, forestry, and animal species in the same space makes local development sustainable, promoting highly diversified production, environmental conservation, and ecological and economic interactions (Martinelli et al., 2019). ...
Litter has fundamental carbon values accumulated in its biomass, with an essential participation in the whole forest system for both carbon sequestration and for the benefits to the biogeochemical cycle in supplying the soil’s nutritional demand. This study aimed to evaluate the litter characteristics of eucalyptus clones regarding the contribution of biomass, carbon, and nutrients in each of its forming fractions in an integrated production system at 10 years of age. The accumulated litterfall production of two hybrids, Eucalyptus urophylla x E. grandis (AAC 645) and E. urophylla x E. camaldulensis (AAC 33), was evaluated. The collection was
carried out in 1 m2 plots for each clone, and the accumulated litter biomass, carbon content, nutrient content, and stock of each litter component were evaluated. Clone AAC 645 had the highest litter biomass and carbon stock. The branch fraction in both clones showed higher biomass accumulated carbon averages, and nutritional support. Clone AAC 645 had higher total nutrient content, except for Ca, Mg, and S.
... Glaser et al. 34 stated that OC in the soil is a key to productivity where the soil has low fertility. This can increase food production by 17.6 Mt/year 35,36 . An additional one-ton increase in the OC in the soil can increase wheat yield by 20-40 kg haG 1 , maize by 10-20 kg haG 1 and cowpea by 0.5 kg haG 1 . ...
... In the program for adaptation to climate change the adopted strategy is to invest more effectively in agriculture, promoting diversified systems and the sustainable use of biodiversity and water resources, with support for the transition process, production organization, income generation guarantee, research with genetic resources and improvement, water resources, adaptation of productive systems, identification of vulnerabilities, among other initiatives (Brasil, 2012). As for the program for Planted Forests, the strategy is to promote reforestation actions in the country, expanding the reforested area destined to produce fibers, wood, and cellulose, contributing to the capture of CO2 (Brasil, 2012 (Sa et al., 2017) To address the potential of LCA (low-carbon agriculture) strategies to mitigate climate change and promote food security in South America. ...
This article aimed to present the goals of the ABC Plan for low-carbon agriculture, and uses the multiple regressions modeling technique to investigate economic activity variables in relation to CO2 emissions over the period from 1990 to 2018 in all Brazilian states. The results show that the CO2 emissions in the states, have the same behavior as the land use change timeline, and that public policies and society actions were fundamental to the decrease verified in both CO2 emissions and the change in use, of the land observed from the year 2004 until 2010. From this year, followed a trend of stability in CO2 emissions and land use change. Another important characteristic is that despite the decrease in the number of deforestations, economic activities continued to grow in the regions, which demonstrates that there may be an increase in production even though the numbers of deforestation and CO2 emissions are decreasing. This information, strengthen the Low Carbon Agriculture Program, as the main strategy for the development of the productive sector, mainly for sustainable agriculture.
... Soil degradation and the loss of organic matter lead to the release of the carbon stored in the soil, transferring it into the atmosphere where it contributes to the GHG effect, accelerating climate change. Different agricultural management, including farming techniques, such as low-carbon agriculture, can enhance carbon sequestration in the soil [81]. ...
Global climate change, induced by anthropogenic causes, has severe consequences for Earth and its inhabitants. With the consequences already visible around the globe, one of them is the impact on food security. The lack of food security has serious impacts on health, especially in vulnerable populations who highly depend on a nutritious diet for a healthy life. The following research aims to assess the current research status of climate change, food security and health. In this context, the interlinkage of the three key concepts is analyzed, as well as the related health consequences. To achieve the aims of this research, a bibliometric analysis was conducted using VOSviewer, (version 1.6.16) including 453 papers. The data were retrieved from the Scopus database on 10 November 2022. Bibliometric analysis can illustrate emerging and key topic areas using keywords and co-occurrence analysis; hence, it is an adequate method to meet the listed research aims. Five different clusters have been derived from the analysis, each representing a different perspective on interlinkage. From the different clusters, the main consequences of climate change on food security could be derived, such as a decrease in crop yields, less availability of fish and livestock, or food contamination through mycotoxins. These can cause serious health implications, predominantly increasing the rate of malnutrition globally. The work showed the importance of action to prevent the consequences of climate change in relation to food security and health nexus. To do so, adaptation strategies are needed that consider the interdisciplinary scope of the problem, building sustainable measures that benefit each concept.
... In terms of sustainability, a higher soil fertility is associated with higher soil biodiversity and better nutrient recycling and can help to reduce nitrous oxide emissions, the incidence of pests and diseases, and the use of pesticides, fertilisers, and fuel/energy [11][12][13][14] . With regard to climate change, a higher soil fertility can help to improve the climate resilience (abiotic stress tolerance to hot and drought periods or heavy rainfall events) of plants and entire cropping systems by increasing water availability, which results from increases in soil water storage capacity, rootability, and aggregate stability [14][15][16][17] . ...
Healthy and productive agricultural soils are the basis for global food security as they are a prerequisite for yield-stable cropping systems under climate change. Despite the expansion of agricultural research activities in this area through field experiments, lab analyses, and modelling frameworks, current empirical insights from farming practice on a more national scale are still rare. For this reason, the agronomic importance of soil fertility for farming practice was the focus of this nationwide empirical study conducted in Germany (winter/spring 2022) with a total sample size of 585. The views and needs of 370 farmers and 215 agricultural institutionalists were evaluated, i.a., regarding the importance of soil fertility and related soil properties, as well as preferred agronomic management strategies and needs for the promotion of soil fertility. The results showed that most farmers and institutionalists consider soil fertility to be very important. Moreover, it was emphasized that the importance of this factor will increase in the future due to changing climatic conditions (e.g., heat/drought stress) and the need for more sustainable land use including the protection of biodiversity. The main motivations for agronomic investments in greater soil fertility were improving the climate resilience and yield stability of cropping systems. In this context, the top soil properties of interest were ranked by the respondents as follows: (1) water storage capacity, (2) rootability, (3) biological activity, and (4) water infiltration rate. To promote soil fertility, farmers mainly considered catch cropping, diversified crop rotations with a positive humus balance, and year-round ground plant cover/mulch as the most useful agronomic measures. In terms of methods for the assessment of soil fertility, soil structure analyses, biological indicators, yield/biomass production, soil nutrient analyses, and field methods were most important, whereas sensor systems and apps/digital tools were of minor importance. For the future improvement of soil fertility promotion in farming practice, simple indicators and reference values for assessing soil fertility as well as 'workshops, field days, and field schools' for training aspects were suggested by the participants. Overall, there were few differences between the perceptions of farmers and agricultural institutionalists. Both groups pointed out the need for improved communication between politics, science, and practice such that agriculture can respond more quickly to changing climatic conditions in the future.
... Dessa maneira, o cultivo de leguminosas, como o guandu, torna possível a disponibilidade de N aos sistemas de produção agropecuários através da fixação biológica de nitrogênio, reduzindo a necessidade de aplicação de fertilizantes minerais. Além de fornecer proteção física ao solo devido à rápida produção de biomassa (SÁ et al., 2017). ...
The Pigeon pea (Cajanus cajan) is a shrub legume with multiple uses. The species has a very well-organized and deep root system, which allows it to resist drought. In addition, pigeon pea can associate with nitrogen-fixing bacteria. These characteristics make pigeon pea a viable alternative in the recovery of degraded soils. As green manure, it guarantees more nutrients for the main crop, thanks to its ability to supply nitrogen to the system. It is a source of food for humans and animals and still adapts well in semi-arid regions. Pigeon pea has shown good results under Cerrado conditions, being an option for diversifying agricultural systems in the region. For the incorporation of this species in agricultural systems, information is needed on the adaptation of the genotypes to the region of cultivation and the destination of the plantation, given the genetic variability and the multiple uses that the species has. However, this information is still scarce and even the existing information needs to reach more farmers and the population in general. In this sense, this review aims to address the main potential use of pigeon pea in the Brazilian cerrado region.
... For these reasons, CLI has recently been used by the Brazilian government to define public policies on agricultural credit, deforestation control and greenhouse gas mitigation. These actions stand out as commitments made under the international climate agreement of Paris-COP 21 [42][43][44]. Figure 3 also shows that all the management systems with grass in free growth had a lower decomposition rate than those with the grazing simulation cut. This is due to the development of the reproductive phase of the forage plants, which leads to an increase in stalks compared to leaves, made up of fibrous materials rich in lignin and cellulose, reducing the rate of the decomposition of the forage plant. ...
Soybean is one of the most widely grown crops in the world and technologies are increasingly needed to increase productivity without impacting environmental degradation. In this context, the aim was to evaluate the action of forage plants of the genus Brachiaria sp. in crop–livestock integration on physical soil, agronomic and environmental aspects of soybean cultivation. The experiment was conducted in a subdivided plot design with seven integrated systems corresponding to the previous cultivation of Paiaguas palisadegrass, Xaraes palisadegrass and Ruziziensis grass in monocropping and intercropped with maize, as well as maize in monocropping. In the subplots, two grass management systems were evaluated: free growth and a grazing simulation cut. The bulk density and least limiting water range were assessed using soil samples and, after the pastures were desiccated when the soybean crop was planted, straw decomposition and plantability. A soil physics diagnosis by the bulk density and least limiting water range showed that the Paiaguas palisadegrass and Xaraes palisadegrass improved the soil environment due to biological soil loosening. The remaining mulch biomass did not affect soybean sowing and the adoption of Brachiaria sp. grass in the off-season, in addition to contributing to the provision of environmental services, and did not compromise grain productivity in succession.
... This is of great importance especially to subsistence farmers with limited resources to access the mineral fertilizers and therefore highly dependent on economically viable and prudent biological processes to sustain yields (Graham and Vance, 2003). BNF contribute little to greenhouse gas emissions as they generate low nitrous oxide compared to the amount emitted with mineral N fertilizer reducing impacts of climatic shocks (Bayer et al., 2016;Sá et al., 2016). ...
Maize is a strategic staple crop serving both as human food and feed in the livestock sector. It therefore has a critical socioeconomic value safeguarding against food and nutrition insecurity. Maize yields are however low especially among smallholder farmers who rely on this crop for their livelihood and sustenance. This has rendered most Sub-Saharan Africa countries such as Kenya to be net importers and depended on food aid mainly in form of maize. Even though white maize variety is nutritionally inferior, it is the most produced and consumed with little regard placed on yellow maize. We reviewed 154 articles and reports to highlight challenges facing maize production and sustainable agricultural practices that should be embraced to overcome them, nutritional benefits of yellow maize, factors hindering its consumption and research gaps that need to be addressed to enhance its production and utilization. Key production challenges identified include shrinking land sizes, declining soil fertility, adverse and unpredictable weather patterns and the devastating striga weed. Intercropping especially cereals with legumes have great potential for efficient land, water and nutrient resource utilization, manage weeds and minimize crop failure and adverse weather effects. This combined with integrated soil fertility management will ensure increased yields. It was found that yellow maize has higher carotenoid content hence superior to white maize and when taken with grain legumes provides a low-cost balanced diet. Despite this, yellow maize utilization is low because it is regarded as poor man’s crop, associated with food aid and reserved as livestock feed. This negative perception can be changed through educational campaigns on its nutritional value in order to enhance local production and encourage social acceptability to aid alleviate vitamin A deficiency, a key limiting micronutrient. In conclusion, tapping in the nutritional superiority of yellow maize through legume intercropping should be enhanced.
... In Poland a limiting factor for soybean is cultivar progress related to the adaptation of cultivars to the country's climate and soil conditions, taking into account the lenght of vegetation season and available sunlight and temperature 2 . The application of new technologies to increase seed yield and quality is necessary for sustainable agriculture and low carbon emissions 3,4 . Therefore, practices that minimize and/or optimize input use should be applied in agricultural systems 5 . ...
Soybean, belonging to legumes, has a specific ability to biological nitrogen fixation, which can be reinforced by seeds inoculation. However, support with a starter dose of mineral nitrogen fertiliser may be necessary to achieve high seed yields. A four-year field experiment was conducted to determine the effect of mineral N fertilization (0, 30, 60 kg∙ha − 1 ), seed inoculation with different commercial preparation (HiStick Soy and Nitragina) and combinations of these treatments on yield components and yielding of soybean in conditions of south-western part of Poland. The synergistic effect of mineral fertilization at dose 30 kg ha − 1 and inoculation on soybean productivity was the most beneficial. Similar effects were observed when 60 kg N·ha − 1 was applied both separately and with inoculation. However, due to the environmental impact of mineral fertilisers and to promote plants to BNF, it is advisable to use lower doses of N fertiliser (at 30 kg∙ha − 1 ) and inoculate soybean seeds in agro- climatic conditions of south-western Poland.
... Additionally, our analysis identified a significant positive correlation between SOC and yield changes, although the correlation coefficients were relatively small (R 2 < 0.25, Figures 3-7). It has been well-demonstrated that conservation agriculture can increase SOC content (de S a et al., 2017;Powlson et al., 2014), which in turn can significantly enhance corn yields (Bisheng et al., 2015). Recent research utilizing pedotransfer functions has further demonstrated a positive relationship between SOC increases T A B L E 1 Comparison of simple linear regression (SLR) coefficients to determine when it is the necessity to log-transform the response ratio (RR x ) of different soil properties. ...
Conservation agriculture (CA) has the potential to sustain soil productivity and benefit agroecosystems, yet it is not fully understood how yield responses of different cropping systems are affected by inherent soil characteristics, e.g., texture and dynamic soil properties, such as aggregation, nutrients, and erosion. In this study, we conducted a systematic review to compare crop yield from cropland with conventional management versus different CA practices, specifically reduced‐ or no‐tillage, agroforestry, organic farming, and cover crops. The data were first analyzed for different climatic regions, soil textures, and cash crop types. We then quantified how yield responses correlated with soil properties changes under different CA practices. The results showed that CA practices were associated with an overall mean crop yield increase of 12%. This response was primarily driven by corn, which had a mean yield increase of almost 41% after CA implementation, whereas other cash crops did not have significant yield responses or showed slight decreases, as rotation with mixtures of multiple cash crops had mean decrease of 6% when using CA. The increase in corn yield after CA may be related to the enhanced ability of that crop to absorb nutrient elements (e.g., nitrogen) and reduce nutrient leaching. Agroforestry increased crop yield by 66% and cover cropping increased yield by 11%, likely due to increases in soil water content and nutrient availability and decreases in erosion and surface runoff. However, other agricultural systems showed no significant increase after CA compared to conventional row cropping practices. Using CA practices had the greatest yield benefit in tropical climates and when farming in coarse‐textured soils. In addition, legumes and grass‐legume mixtures resulted in significant cash crop yield increases, possibly because legumes promoted the increase of soil nitrogen and depleted soil moisture less compared with other cover crops. The results provide new insight into how interactions between soil properties and CA practices affect crop yield, and at the same time can help guide the development of practical, evidence‐based guidelines for using conservation practices to improve yield in corn and other cash crops.
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... Currently, global average carbon prices remain far below the US$40-$80/tCO 2 range necessary to cost-effectively reduce emissions in line with the Paris Agreement (World Bank 2019, 2020). However, climate-smart agriculture appears to offer viable means of GHG sequestration in low-income communities (Mbow et al. 2014;Lal 2015;Sa et al. 2017). There may be a tipping point where the monitoring technologies, ETS mechanisms, and HIC regulatory and tax policy suddenly make GHG sequestration a viable income source (or supplement) for rural landowners in Africa and Asia. ...
... Active forest restoration, by planting diverse native plant species to rapidly cover the soil and rehabilitate ecological functions (Brancalion et al., 2015Zanini et al., 2021), is the most cost-efficient method in such cases (Ribeiro et al., 2009). Recovering degraded pastures and restoring Atlantic forests are urgent and critical socio-environmental challenges for Brazil to fulfill the agreements to mitigate the climate crisis (Sá et al., 2017;Rezende et al., 2018), helping to re-establish environmental services (Lima et al., 2020) and reverse ecosystem degradation (Zanini et al., 2021), simultaneously contributing to global efforts on the UN Decade on Ecosystem Restoration (Bieluczyk et al., 2023). ...
Forest restoration mitigates climate change by removing CO2 and storing C in terrestrial ecosystems. However, incomplete information on C storage in restored tropical forests often fails to capture the ecosystem's holistic C dynamics. This study provides an integrated assessment of C storage in above to belowground subsystems, its consequences for greenhouse gas (GHG) fluxes, and the quantity, quality, and origin of soil organic matter (SOM) in restored Atlantic forests in Brazil. Relations between SOM properties and soil health indicators were also explored. We examined two restorations using tree planting ('active restoration'): an 8-year-old forest with green manure and native trees planted in two rounds, and a 15-year-old forest with native-planted trees in one round without green manure. Restorations were compared to reformed pasture and primary forest sites. We measured C storage in soil layers (0-10, 10-20, and 20-30 cm), litter, and plants. GHG emissions were assessed using CH4 and CO2 fluxes. SOM quantity was evaluated using C and N, quality using humification index (HLIFS), and origin using δ13C and δ15N. Nine soil health indicators were interrelated with SOM attributes. The primary forest presented the highest C stocks (107.7 Mg C ha-1), followed by 15- and 8-year-old restorations and pasture with 69.8, 55.5, and 41.8 Mg C ha-1, respectively. Soil C stocks from restorations and pasture were 20% lower than primary forest. However, 8- and 15-year-old restorations stored 12.3 and 28.3 Mg ha-1 more aboveground C than pasture. The younger forest had δ13C and δ15N values of 2.1 and 1.7 ‰, respectively, lower than the 15-year-old forest, indicating more C derived from C3 plants and biological N fixation. Both restorations and pasture had at least 34% higher HLIFS in deeper soil layers (10-30 cm) than primary forest, indicating a lack of labile SOM. Native and 15-year-old forests exhibited higher soil methane influx (141.1 and 61.9 µg m-² h-¹). Forests outperformed pasture in most soil health indicators, with 69% of their variance explained by SOM properties. However, SOM quantity and quality regeneration in both restorations approached the pristine forest state only in the top 10 cm layer, while deeper soil retained agricultural degradation legacies. In conclusion, active restoration of the Atlantic Forest is a superior approach compared to pasture reform for GHG mitigation. Nonetheless, the development of restoration techniques to facilitate labile C input into deeper soil layers (> 10 cm) is needed to further improve soil multifunctionality and long-term C storage.
... While the available global reserves for water are sufficient to meet the current and future demands, they are unevenly distributed (Cosgrove and Loucks, 2015). Some regions are privileged with accessible water resources satisfying basic daily-life requirements, whilst others maybe water scarce, or are unable to benefit from their water resources despite its abundance. ...
Soil represents Earth’s largest terrestrial reservoir of carbon (C) and is an important sink of C from the atmosphere. However, the potential of adopting best management practices (BMPs) to increase soil C sequestration and offset greenhouse gas (GHG) emissions in agroecosystems remains unclear. Synthesizing available information on soil C sink capacity is important for identifying priority areas and systems to be monitored, an essential step to properly estimate large-scale C sequestration potential. This study brings an overview of thousands of research articles conducted in the Americas and presents the current state-of-the-art on soil C research. Additionally, it estimates the large-scale BMPs adoption impact over soil C dynamics in the region. Results indicated that soil C-related terms are widely cited in the literature. Despite that, from a total of ~13 thousand research articles recovered in the systematic literature review, only 9.2% evaluated soil C (at any depth), and only 4.6% measured soil C for the 0–30 cm soil layer, mostly conducted in North and South America regions. Literature review showed a low occurrence of terms related to BMPs (e.g., cover cropping), suggesting a research gap on the subject. Estimates revealed that upscaling of BMPs over 30% of agricultural land area (334 Mha) of the Americas can lead to soil C sequestration of 13.1 (±7.1) Pg CO2eq over 20 years, offsetting ~39% of agricultural GHG emissions over the same period. Results suggest that efforts should be made to monitor the impact of cropping system on soil C dynamics on the continents, especially in regions where data availability is low (e.g., Central, Caribbean, and Andean regions). Estimating the available degraded area for the continent and the soil C sequestration rates under BMPs adoption for Central, Andean, and Caribbean regions were major shortcomings encountered in our analysis. Thus, it is expected that some degree of uncertainty may be associated with the obtained results. Despite these limitations, upscaling of BMPs across the Americas suggests having great potential for C removal from the atmosphere and represents a global positive impact in terms of climate change mitigation and adaptation.
This chapter explored the challenges and consequences of soil degradation in the Global South. Soil health and productivity are vital for food security, sustainable agriculture, and livelihoods. The chapter provides an overview of prevalent soil degradation types and their causes examines the impacts of soil degradation on agriculture, food production, and rural communities, as well as its link to water resources and biodiversity. Some case studies highlighting specific threats to soil in different parts of the Global South were provided as well as relevant policies, practices, and interventions for soil conservation, including existing regulations, sustainable land management, and technology. It also emphasized the importance of strengthening soil governance and capacity building. Opportunities for sustainable soil management were identified, such as the synergies between soil health and climate change mitigation. Agro-ecological approaches and regenerative agriculture were suggested as pathways for improvement. The chapter also emphasized the potential for international collaboration and partnerships. This chapter concludes by calling for urgent action to protect and restore soil resources through sustainable practices, strengthened governance, and increased capacity building. By recognizing the importance of soil health, the Global South can pave the way for a sustainable and resilient future.
Purpose
Reducing carbon emissions in agriculture is vital for fostering sustainable agricultural growth and promoting ecological well-being in rural areas. The adoption of Low-Carbon Agriculture (LCA) by farmers holds great potential to accomplish substantial reductions in carbon emissions. The purpose of this study is to explore the farmers' preference and willingness to engage in LCA.
Design/methodology/approach
This study employs the Choice Experiment (CE) method to examine farmers' preferences and willingness to adopt LCA, using field survey data of 544 rural farmers in the Weihe River Basin between June and July 2023. We further investigate differences in willingness to pay (WTP) and personal characteristics among different farmer categories.
Findings
The empirical results reveal that farmers prioritize government-led initiatives providing pertinent technical training as a key aspect of the LCA program. Farmers' decisions to participate in LCA are influenced by factors including age, gender, education and the proportion of farm income in household income, with their evaluations further shaped by subjective attitudes and habits. Notably, we discovered that nearly half of the farmers exhibit indifference towards LCA attributes.
Originality/value
To the best of the authors' knowledge, this study is the first to investigate farmers' attitudes toward LCA from their own perspectives and to analyze the factors influencing them from both subjective and objective standpoints. This study presents a fresh perspective for advocating LCA, bolstering rural ecology and nurturing sustainable development in developing nations.
Biomass-C agriculture is the primary pathway to develop resilient, profitable, and low-environmental-impact production systems. The legacy that the no-till system (NTS) has promoted since about 1970 has been to minimize soil loss by erosion of 7.1–21.7 billion t and to protect 2.8–8.4 million ha. The NTS on-farm scale is based on three principles: lack of soil disturbance, permanent soil cover, and diverse crop systems. It has been consolidated as the soil management system that produces food in harmony with “Mother Nature.” The NTS evolution scale shows clearly that pedological processes and the attendant changes are guided by interconnected steps acting as a system, and each phase implies some challenges that must be addressed. The establishment of the minimum amount of biomass-C to reach the soil C dynamic equilibrium (3.2 and 5.1 Mg ha−1 yr−1 for subtropical and tropical environments, respectively) was fundamental to understand that production systems that add biomass-C amounts lower than the dynamic equilibrium requirement will have a negative C balance and render soil vulnerable to weather conditions. Therefore, the challenge is to develop production systems with a high biomass-C input based on quantity, quality, and frequency that also lead to low CO2 emissions. Examples of long-term on-farm systems in tropical regions adding 7.4–8.38 Mg C ha−1 yr−1 illustrate how NTS can increase soil organic C (SOC) stocks and generate healthy edaphic environments. In addition, NTS can restore C from natural capital (NC) and recover it in a shorter period than originally thought. Data from several NTS-based studies show that it is possible to recover the historic C lost upon the conversion of soil under native vegetation (NV) into agriculture between 49 and 77 years. The restorative path starts with recovering and protecting aggregates, increasing biological activity, and activating the flow of C and N to be stored in the soil. There is a strong nexus among soil biota, soil health (SH), plant vigor, productivity, healthy food production, human health, and environmental quality. Activities of soil enzymes, such as β-glucosidase (GLU) and arylsulfatase (ARYL), which constitute the pillars of Soil Bioanalysis Technology (SoilBio), have proven to be an efficient tool for understanding field variability in crop yields and for supporting management decisions. A large proportion of the dataset investigated revealed the depleted SOC and total N (TN) stocks that were associated with low enzyme activity and limited microbial biodiversity. These results reinforce the need to fully integrate the three principles of NTS that operate synergistically in order to build and sustain SH in agricultural production systems. Furthermore, the restoration of SOC and TN stocks showed a positive linear relationship with the enzymatic activity that expresses the biological activity. The physical improvement of the soil through aggregation, aeration, and water storage also stimulated the presence of plant growth–promoting soil microorganisms
This review explores the evolution and impact of sustainable chemistry in agriculture. It traces its historical progress, key milestones, and challenges. The article delves into the fundamental principles, emerging technologies, and benefits of incorporating sustainable chemistry into farming practices. It specifically addresses areas like green synthesis, precision farming, soil health, and the use of organic agrochemicals, highlighting their significance in the field of agriculture. Key advancements discussed include sustainable formulations, technological developments, and policy transitions towards environmentally friendly agriculture. Examples of organic action plans are provided to illustrate the policy shifts towards more eco-friendly practices. The review explores the incorporation of circular economy principles in sustainable agriculture, illustrating a comprehensive approach to reducing waste and enhancing resource efficiency. The paper outlines future prospects of sustainable chemistry in agriculture, highlighting emerging trends and interdisciplinary collaborations. It concludes by indicating how sustainable chemistry can address significant challenges, including food scarcity and environmental degradation.
A futuro, la oferta sostenible de alimentos, energía, tierra, y recursos será uno de los mayores retos de la humanidad. El cambio climático afecta al ambiente, impacta negativamente la producción agrícola y aumenta el riesgo de la extinción humana. A esto se agrega el actual modelo de producción, en general ineficiente en el uso del suelo y en la producción en toneladas por hectárea. De continuar este modelo de producción, se aumentarán las emisiones de gases de efecto invernadero a la atmósfera, intensificando los efectos del cambio climático. Tanto los alimentos como la energía deben ser producidos con cero emisiones, mediante la descarbonización del sector agrícola y la aplicación de un modelo de economía baja en carbono. Este artículo hace una compilación de literatura sobre el concepto de economía baja en carbono y analiza su aplicación en la Orinoquia colombiana resaltando la oportunidad de producir bioenergía con bajas emisiones de GEI. La mitigación y adaptación al cambio climático de la Orinoquia es clave para el desarrollo de una economía baja en carbono en la producción agrícola y el uso de la tierra.
The demand for efficient, accurate, and cost-effective methods of measuring soil carbon (C) in agriculture is growing. Traditional approaches are time consuming and expensive, highlighting the need for alternatives. This study tackles the challenge of utilizing laser-induced breakdown spectroscopy (LIBS) as a more economical method while managing its potential accuracy issues due to physical–chemical matrix effects. A set of 1,019 soil samples from 11 Brazilian farms was analyzed using various univariate and multivariate calibration strategies. The artificial neural network (ANN) demonstrated the best performance with the lowest root mean square error of prediction (RMSEP) of 0.48 wt% C, a 28% reduction compared to the following best calibration method (matrix-matching calibration – MMC inverse regression and multiple linear regression – MLR at 0.67 wt% C). Furthermore, the study revealed a strong correlation between total C determined by LIBS and the elemental CHNS analyzer for soils samples in nine farms (R² ≥ 0.73). The proposed method offers a reliable, rapid, and cost-efficient means of measuring total soil C content, showing that LIBS and ANN modeling can significantly reduce errors compared to other calibration methods. This research fills the knowledge gap in utilizing LIBS for soil C measurement in agriculture, potentially benefiting producers and the soil C credit market. Specific recommendations include further exploration of ANN modeling for broader applications, ensuring that agricultural soil management becomes more accessible and efficient.
Context Land use change (LUC) is considered one of the main factors associated with soil carbon (C) loss worldwide. Aim Evaluate changes in labile and non-labile soil organic matter (SOM) fractions in different land use systems – native vegetation (NV), agriculture with conventional cultivation (CC) and pasture (PA) – in five soil classes in the Brazilian semi-arid region. Methods Soil samples were collected to a depth of 100 cm, and soil C and nitrogen (N) content and stocks were determined and also stocks of labile (LC) and non-labile (NlC) C fractions. In addition, the Carbon Management Index (CMI) was used to evaluate soil health changes. Key results SOC stocks significantly decreased after conversion from NV to CC (by 23%; 0–30 cm) and PA (by 22%; 0–100 cm). Losses due to LUC were greater in the LC than the NlC fraction, and this was reflected in the CMI reducing by 37% for PA and 57% for CC in the 0–100 cm layer. Regarding the different soil classes, LUC reduced SOC stocks only in the Luvisol, Planosol and Leptosol classes, while in the LC fraction, changes were observed in Acrisols, Cambisols and Planosols. Conclusions Clearing NV areas for CC systems and PA reduced the SOC stocks and SOM fractions and, consequently, decreased soil quality. Implications These findings underscore the importance of considering the quality of SOM when evaluating LUC impacts on SOC stocks in the different classes of soil in the Brazilian semi-arid region.
Com o avanço das mudanças climáticas, as avaliações de riscos contribuem para reduzir a vulnerabilidade e melhorar a segurança alimentar. Estratégias nacionais e planos de adaptação para aliviar os impactos negativos das mudanças climáticas são essenciais para um futuro de baixo carbono e resiliente ao clima, sendo a agropecuária parte importante da solução. Este estudo explora a relação dinâmica entre a mudança nas variáveis climáticas essenciais do conjunto multimodelo Coupled Model Intercomparison Project Phase 6 (CMIP6) da plataforma Climate Change Knowledge Portal (CCKP) e as estratégias de adaptação da agropecuária sul-mato-grossense com o objetivo de especificar e diferenciar sistematicamente as medidas de adaptações, resumindo o progresso prático da neutralidade de carbono, o caminho de realização da neutralidade de carbono e a pesquisa de neutralidade de carbono. As projeções do CMIP6 demonstraram um ambiente climático preocupante à produção agropecuária sul-mato-grossense, em especial ao aumento na temperatura média do ar, em até 1.5ºC para o ano de 2030. Entretanto, políticas de desenvolvimento e adoção de práticas sustentáveis de produção vêm sendo criadas, testadas e praticadas no campo, sendo primordiais para o Estado de Mato Grosso do Sul atingir a grande meta de neutralização do carbono em 2030. Todavia, a desaceleração na redução dos gases de efeito estufa evidencia a neutralidade para 2035 otimista, 2045 marginal e 2070 pessimista.
Over the last half-century, global attention has focused on climate change, particularly changes in air temperature. Concerns about the sustainability of the Earth’s ecosystems and other human life on the land are increasing along with population growth, rising surface temperature, and higher greenhouse gas (GHG) emissions. Agriculture is responsible for ~18% of total GHG emissions. Therefore, mitigating the effects of climate change by reducing GHG emissions is essential and can be achieved by careful evaluation of the carbon footprint (CF). The goal of this study was to gain a better understanding of the changes in CF due to agricultural management practices. Carbon footprint is a popular concept in agro-environmental sciences owing to its role in the environmental impact assessments related to alternative solutions and global climate change. The CF of agricultural products is one of the most crucial indicators to assess the effectiveness and long-term viability of agricultural products. Soil-moisture content, soil temperature, porosity, and anoxic conditions are some of the soil properties directly related to GHG
emissions. The GHG emissions are also affected by different land-use changes, soil types, and agricultural management practices. Globally, better soil-management techniques can alter atmospheric GHG emissions. Therefore, the relation between photosynthesis and GHG emissions is impacted by agricultural management practices, especially focusing on soil and related systems. When maximizing crop productivity, environmental factors, land use, and agricultural practices all should be considered in CF management. The current review highlights the importance of CF and its role in maintaining the sustainability of agricultural systems.
In this paper, soil carbon, nitrogen and phosphorus concentrations and stocks
were investigated in agricultural and natural areas in 17 plot-level paired
sites and in a regional survey encompassing more than 100 pasture
soils In the paired sites, elemental soil concentrations and stocks were
determined in native vegetation (forests and savannas), pastures and
crop–livestock systems (CPSs). Nutrient stocks were calculated for the soil
depth intervals 0–10, 0–30, and 0–60 cm for the paired sites and
0–10, and 0–30 cm for the pasture regional survey by sum stocks
obtained in each sampling intervals (0–5, 5–10, 10–20, 20–30, 30–40, 40–60 cm). Overall, there were significant differences in soil element
concentrations and ratios between different land uses, especially in the
surface soil layers. Carbon and nitrogen contents were lower, while
phosphorus contents were higher in the pasture and CPS soils than in native
vegetation soils. Additionally, soil stoichiometry has changed with changes
in land use. The soil C : N ratio was lower in the native vegetation than in
the pasture and CPS soils, and the carbon and nitrogen to available
phosphorus ratio (PME) decreased from the native vegetation to the
pasture to the CPS soils. In the plot-level paired sites, the soil nitrogen
stocks were lower in all depth intervals in pasture and in the CPS soils when
compared with the native vegetation soils. On the other hand, the soil
phosphorus stocks were higher in all depth intervals in agricultural soils
when compared with the native vegetation soils. For the regional pasture
survey, soil nitrogen and phosphorus stocks were lower in all soil intervals
in pasture soils than in native vegetation soils. The nitrogen loss with
cultivation observed here is in line with other studies and it seems to be a
combination of decreasing organic matter inputs, in cases where crops
replaced native forests, with an increase in soil organic matter
decomposition that leads to a decrease in the long run. The main cause of
the increase in soil phosphorus stocks in the CPS and pastures of the
plot-level paired site seems to be linked to phosphorus fertilization
by mineral and organics fertilizers. The findings of this paper illustrate
that land-use changes that are currently common in Brazil alter soil
concentrations, stocks and elemental ratios of carbon, nitrogen and
phosphorus. These changes could have an impact on the subsequent vegetation,
decreasing soil carbon and increasing nitrogen limitation but alleviating soil
phosphorus deficiency.
We summarise the contemporary carbon budget of South America and relate it to its dominant controls: population and economic growth, changes in land use practices and a changing atmospheric environment and climate. Component flux estimate methods we consider sufficiently reliable for this purpose encompass fossil fuel emission inventories, biometric analysis of old-growth rainforests, estimation of carbon release associated with deforestation based on remote sensing and inventories, and agricultural export data. Alternative methods for the estimation of the continental-scale net land to atmosphere CO2 flux, such as atmospheric transport inverse modelling and terrestrial biosphere model predictions, are, we find, hampered by the data paucity, and improved parameterisation and validation exercises are required before reliable estimates can be obtained. From our analysis of available data, we suggest that South America was a net source to the atmosphere during the 1980s (∼ 0.3-0.4 Pg C a−1) and close to neutral (∼ 0.1 Pg C a−1) in the 1990s. During the latter period, carbon uptake in old-growth forests nearly compensated for the carbon release associated with fossil fuel burning and deforestation. Annual mean precipitation over tropical South America as inferred from Amazon River discharge shows a long-term upward trend. Although, over the last decade dry seasons have tended to be drier, with the years 2005 and 2010 in particular experiencing strong droughts. On the other hand, precipitation during the wet seasons also shows an increasing trend. Air temperatures have also increased slightly. Also with increases in atmospheric CO2 concentrations, it is currently unclear what effect these climate changes are having on the forest carbon balance of the region. Current indications are that the forests of the Amazon Basin have acted as a substantial long-term carbon sink, but with the most recent measurements suggesting that this sink may be weakening. Economic development of the tropical regions of the continent is advancing steadily, with exports of agricultural products being an important driver and witnessing a strong upturn over the last decade.
This paper updates the SCVI (Socio-Climatic Vulnerability Index) maps developed by Torres et al. (2012) for Brazil, by using the new Coupled Model Intercomparison Project Phase 5 (CMIP5) projections and more recent 2010 social indicators data. The updated maps differ significantly from their earlier versions in two main ways. First, they show that heavily populated metropolitan areas – namely Belo Horizonte, Brasília, Salvador, Manaus, Rio de Janeiro and São Paulo – and a large swath of land across the states of São Paulo, Minas Gerais and Bahia now have the highest SCVI values, that is, their populations are the most vulnerable to climate change in the country. Second, SCVI values for Northeast Brazil are considerably lower compared to the previous index version. An analysis of the causes of such difference reveals that changes in climate projections between CMIP3 and CMIP5 are responsible for most of the change between the different SCVI values and spatial distribution, while changes in social indicators have less influence, despite recent countrywide improvements in social indicators as a result of aggressive anti-poverty programs. These results raise the hypothesis that social reform alone may not be enough to decrease people’s vulnerability to future climatic changes. Whereas the coarse spatial resolution and relatively simplistic formulation of the SCVI may limit how useful these maps are at informing decision-making at the local level, they can provide a valuable input for large-scale policies on climate change adaptation such as those of the Brazilian National Policy on Climate Change Adaptation.
The Brazilian government aims at augmenting the area cropped under no-tillage (NT) from 32 to 40 million ha by 2020 as a means to mitigate CO2 emissions. We estimated soil carbon (C) sequestration under continuous NT systems in two municipalities in the Goiás state that are representative of the Cerrado. A chronosequence of NT fields of different age since conversion from conventional tillage (CT) was sampled in 2003 and 2011. Soil C levels of native Cerrado and pasture were measured for comparison. After about 11 to 14 years, soil C stocks under NT were highest and at the levels of those under natural Cerrado. Average annual rates of soil C sequestration estimated using the chronosequence approach were respectively 1.61 and 1.48 Mg C ha−1 yr−1 for the 2003 and 2011 sampling, and were higher than those observed using repeated sampling after eight years. The diachronic sampling revealed that the younger NT fields tended to show higher increases in soil C stocks than the older fields. Converting an extra 8 million ha of cropland from CT to NT represents an estimated soil C storage of about 8 Tg C yr−1 during 10 to 15 years.
The global empirical evidence shows that farmer-led transformation of agricultural production systems based on Conservation Agriculture (CA) principles is already occurring and gathering momentum globally as a new paradigm for the 21st century. The data presented in this paper has been collected by the Food and Agriculture Organization of the United Nations from several sources including estimates made by ministries of agriculture, by farmer organizations, and well-informed individuals in research or development organizations; they provide an overview of CA adoption and spread by country, as well as the extent of CA adoption by continent. CA systems, comprising no or minimum mechanical soil disturbance, organic mulch soil cover, and crop species diversification, in conjunction with other good practices of crop and production management, are now (in 2013) practiced globally on about 157 M ha, corresponding to about 11% of field cropland, in all continents and most land-based agricultural ecologies, including in the various temperate environments. This change constitutes a difference of some 47% globally since 2008/09 when the spread was recorded as 106 M ha. The current total of 157 M ha represents an increase in adoption of CA by more countries but the estimate is on the conservative side as the updated database does not capture all the CA cropland. While in 1973/74 CA systems covered only 2.8 M ha worldwide, the area had grown in 1999, to 45 M ha, and by 2003 the area had grown to 72 M ha. In the last 10 years CA cropland has expanded at an average rate of more than 8.3 M ha per year and since 2008/2009 at the rate of some 10 M ha per year, showing the increased interest of farmers and national governments in this alternate production concept and method. Adoption has been intense mainly in North and South America as well as in Australia and Asia, and more recently in Europe and Africa where the awareness of and support for CA is on the increase.
Mapping cropland distribution over large areas has attracted great attention in recent years, however, traditional pixel-based classification approaches produce high uncertainty in cropland area statistics. This study proposes a new approach to map fractional cropland distribution in Mato Grosso, Brazil using time series MODIS enhanced vegetation index (EVI) and Landsat Thematic Mapper (TM) data. The major steps include: (1) remove noise and clouds/shadows contamination using the Savizky-Gloay filter and temporal resampling algorithm based on the time series MODIS EVI data; (2) identify the best periods to extract croplands through crop phenology analysis; (3) develop a seasonal dynamic index (SDI) from the time series MODIS EVI data based on three key stages: sowing, growing, and harvest; and (4) develop a regression model to estimate cropland fraction based on the relationship between SDI and Landsat-derived fractional cropland data. The root mean squared error of 0.14 was obtained based on the analysis of randomly selected 500 sample plots. This research shows that the proposed approach is promising for rapidly mapping fractional cropland distribution in Mato Grosso, Brazil.
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and
their redistribution among the atmosphere, ocean, and terrestrial biosphere
is important to better understand the global carbon cycle, support the
development of climate policies, and project future climate change. Here we
describe data sets and a methodology to quantify all major components of the
global carbon budget, including their uncertainties, based on the combination
of a range of data, algorithms, statistics, and model estimates and their
interpretation by a broad scientific community. We discuss changes compared
to previous estimates as well as consistency within and among components, alongside
methodology and data limitations. CO2 emissions from fossil fuels and
industry (EFF) are based on energy statistics and cement production
data, while emissions from land-use change (ELUC),
mainly deforestation, are based on combined evidence from land-cover-change
data, fire activity associated with deforestation, and models. The global
atmospheric CO2 concentration is measured directly and its rate of
growth (GATM) is computed from the annual changes in concentration.
The mean ocean CO2 sink (SOCEAN) is based on observations from
the 1990s, while the annual anomalies and trends are estimated with ocean
models. The variability in SOCEAN is evaluated with data products
based on surveys of ocean CO2 measurements. The global residual
terrestrial CO2 sink (SLAND) is estimated by the difference of
the other terms of the global carbon budget and compared to results of
independent dynamic global vegetation models forced by observed climate,
CO2, and land-cover change (some including nitrogen–carbon interactions).
We compare the mean land and ocean fluxes and their variability to estimates
from three atmospheric inverse methods for three broad latitude bands. All
uncertainties are reported as ±1σ, reflecting the current
capacity to characterise the annual estimates of each component of the global
carbon budget. For the last decade available (2005–2014), EFF was
9.0 ± 0.5 GtC yr−1, ELUC was
0.9 ± 0.5 GtC yr−1, GATM was
4.4 ± 0.1 GtC yr−1, SOCEAN was
2.6 ± 0.5 GtC yr−1, and SLAND was
3.0 ± 0.8 GtC yr−1. For the year 2014 alone, EFF grew to
9.8 ± 0.5 GtC yr−1, 0.6 % above 2013, continuing the growth
trend in these emissions, albeit at a slower rate compared to the average
growth of 2.2 % yr−1 that took place during 2005–2014. Also, for
2014, ELUC was 1.1 ± 0.5 GtC yr−1, GATM was
3.9 ± 0.2 GtC yr−1, SOCEAN was
2.9 ± 0.5 GtC yr−1, and SLAND was 4.1 ±
0.9 GtC yr−1. GATM was lower in 2014 compared to the past
decade (2005–2014), reflecting a larger SLAND for that year. The
global atmospheric CO2 concentration reached 397.15 ± 0.10 ppm
averaged over 2014. For 2015, preliminary data indicate that the growth in
EFF will be near or slightly below zero, with a projection of −0.6
[range of −1.6 to +0.5] %, based on national emissions projections
for China and the USA, and projections of gross domestic product corrected for
recent changes in the carbon intensity of the global economy for the rest of
the world. From this projection of EFF and assumed constant
ELUC for 2015, cumulative emissions of CO2 will reach about
555 ± 55 GtC (2035 ± 205 GtCO2) for 1870–2015, about
75 % from EFF and 25 % from ELUC. This living
data update documents changes in the methods and data sets used in this new
carbon budget compared with previous publications of this data set (Le
Quéré et al., 2015, 2014, 2013). All observations presented here can
be downloaded from the Carbon Dioxide Information Analysis Center
(doi:10.3334/CDIAC/GCP_2015).
Emissions from agriculture-driven deforestation are of global concern, but
forest land-sparing interventions such as agricultural intensification and
utilization of available non-forest land offer opportunities for mitigation.
In many tropical countries, where agriculture is the major driver of
deforestation, interventions in the agriculture sector could reduce
deforestation emissions as well as reduce emissions in the agriculture
sector. Our study uses a novel approach to quantify agriculture-driven
deforestation and associated emissions in the tropics between 2000 and 2010.
Emissions from agriculture-driven deforestation in the tropics (97
countries) are 4.3 GtCO2e yr−1. We investigate the national
potential to mitigate these emissions through forest land-sparing
interventions, which can potentially be implemented under REDD+.
We
consider intensification and utilization of available non-forested land as
forest land-sparing opportunities since they avoid the expansion of
agriculture into forested land. In addition, we assess the potential to
reduce agricultural emissions on existing agriculture land. The use of a
systematic framework demonstrates the selection of mitigation interventions
by considering sequentially the level of emissions, mitigation potential of
various interventions, enabling environment and associated risks to
livelihoods at the national level. Our results show that considering only
countries with high emissions from agriculture-driven deforestation, with
potential for forest-sparing interventions and a good enabling environment
(e.g. effective governance or engagement in REDD+), there is a potential
to mitigate 1.3 GtCO2e yr−1 (20 countries of 78 with sufficient
data). For countries where we identify agricultural emissions as a priority
for mitigation, up to 1 GtCO2e yr−1 could be reduced from the
agriculture sector including livestock. Risks to livelihoods from
implementing interventions based on national level data call for detailed
investigation at the local level to inform decisions on mitigation
interventions. Three case studies demonstrate the use of the analytical
framework. The inherent link between the agriculture and forestry sectors
due to competition for land suggests that these sectors cannot be considered
independently. Our findings highlight the need to include the forest and the
agricultural sectors in the decision-making process to mitigate
deforestation.
Labile, 'high quality', plant litters are hypothesized to promote soil organic matter (SOM) stabilization in mineral soil fractions that are physico-chemically protected from rapid mineralization. However, the effect of litter quality on SOM stabilization is inconsistent. High quality litters, characterized by high N concentrations, low C/N ratios and low phenol/lignin concentrations, are not consistently stabilized in SOM with greater efficiency than 'low quality' litters characterized by low N concentrations, high C/N ratios and high phenol/lignin concentrations. Here, we attempt to resolve these inconsistent results by developing a new conceptual model that links litter quality to the soil C saturation concept. Our model builds on the Microbial Efficiency-Matrix Stabilization framework (Cotrufo et al., 2013) by suggesting the effect of litter quality on SOM stabilization is modulated by the extent of soil C saturation such that high quality litters are not always stabilized in SOM with greater efficiency than low quality litters. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover-change (some including nitrogen–carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004–2013), EFF was 8.9 ± 0.4 GtC yr−1, ELUC 0.9 ± 0.5 GtC yr−1, GATM 4.3 ± 0.1 GtC yr−1, SOCEAN 2.6 ± 0.5 GtC yr−1, and SLAND 2.9 ± 0.8 GtC yr−1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr−1, 2.3% above 2012, continuing the growth trend in these emissions, ELUC was 0.9 ± 0.5 GtC yr−1, GATM was 5.4 ± 0.2 GtC yr−1, SOCEAN was 2.9 ± 0.5 GtC yr−1, and SLAND was 2.5 ± 0.9 GtC yr−1. GATM was high in 2013, reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004–2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3–3.5%) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO2 yr−1), 65% above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the global economy. From this projection of EFF and assumed constant ELUC for 2014, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870–2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this living data set (Le Quéré et al., 2013, 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP_2014).
There has recently been concern in Brazil whether biological N2 fixation (BNF) is capable of meeting the increased N needs of newly released more productive cultivars, as well as doubts about the advantages of annual reinoculation of seeds. Forty experiments were performed over 3 yr in oxisols containing at least 103 cells of Bradyrhizobium g-1 in the State of Paraná, southern Brazil to estimate the contributions of BNF and of N fertilizer. The experiments were performed at two sites, Londrina and Ponta Grossa, under conventional (CT) or no-tillage (NT) systems, with two cultivars [Embrapa 48 (early-maturing) or BRS 134 (medium-maturity group)]. Treatments included non-inoculated controls without or with 200 kg of N ha -1, and inoculation without or with N fertilizer applied at sowing (30 kg of N ha-1), or at the R2 or R4 stage (50 kg of N ha -1). Compared with the non-inoculated control, reinoculation significantly increased the contribution of BNF estimated by the N-ureide technique (on average from 79 to 84%), grain yield (on average 127 kg ha -1, or 4.7%) and total N in grains (on average 6.6%). The application of 200 kg of N fertilizer ha-1 drastically decreased nodulation and the contribution of BNF (to 44%), with no further gains in yield. Application of starter N at sowing decreased nodulation and the contribution of BNF slightly and did not increase yields, while N fertilizer at R2 and R4 stages decreased the contribution of BNF (to 77%) and also yields. Estimates of volatilization of ammonia ranged from 15 to 25% of the N fertilizer applied, and no residual benefits of the N fertilizer in the winter crop were observed. The results highlight the economical and environmental benefits resulting from replacing N fertilizer with inoculation in Brazil, and reinforce the benefits of reinoculation, even in soils with high populations of Bradyrhizobium.
The Emissions Gap Report 2013 from the United Nations Environment Programme restates the claim that changing to no-till practices in agriculture, as an alternative to conventional tillage, causes an accumulation of organic carbon in soil, thus mitigating climate change through carbon sequestration. But these claims ignore a large body of experimental evidence showing that the quantity of additional organic carbon in soil under no-till is relatively small: in large part apparent increases result from an altered depth distribution. The larger concentration near the surface in no-till is generally beneficial for soil properties that often, though not always, translate into improved crop growth. In many regions where no-till is practised it is common for soil to be cultivated conventionally every few years for a range of agronomic reasons, so any soil carbon benefit is then lost. We argue that no-till is beneficial for soil quality and adaptation of agriculture to climate change, but its role in mitigation is widely overstated.
In this paper soil carbon, nitrogen and phosphorus concentrations and related elemental ratios, as well as and nitrogen and phosphorus stocks were investigated in 17 paired sites and in a regional survey encompassing more than 100 pasture soils in the Cerrado, Atlantic Forest, and Pampa, the three important biomes of Brazil. In the paired sites, elemental soil concentrations and stocks were determined in native vegetation, pastures and crop-livestock systems (CPS). Overall, there were significant differences in soil element concentrations and ratios between different land uses, especially in the surface soil layers. Carbon and nitrogen contents were lower, while phosphorus contents were higher in the pasture and CPS soils than in forest soils. Additionally, soil stoichiometry has changed with changes in land use. The soil C : N ratio was lower in the forest than in the pasture and CPS soils; and the carbon and nitrogen to available phosphorus ratio (PME) decreased from the forest to the pasture to the CPS soils. The average native vegetation soil nitrogen stocks at 0–10, 0–30 and 0–60 cm soil depth layers were equal to approximately 2.3, 5.2, 7.3 Mg ha−1, respectively. In the paired sites, nitrogen loss in the CPS systems and pasture soils were similar and equal to 0.6, 1.3 and 1.5 Mg ha−1 at 0–10, 0–30 and 0–60 cm soil depths, respectively. In the regional pasture soil survey, nitrogen soil stocks at 0–10 and 0–30 soil layers were equal to 1.6 and 3.9 Mg ha−1, respectively, and lower than the stocks found in the native vegetation of paired sites. On the other hand, the soil phosphorus stocks were higher in the CPS and pasture of the paired sites than in the soil of the original vegetation. The original vegetation soil phosphorus stocks were equal to 11, 22, and 43 kg ha−1 in the three soil depths, respectively. The soil phosphorus stocks increased in the CPS systems to 30, 50, and 63 kg ha−1, respectively, and in the pasture pair sites to 22, 47, and 68 kg ha−1, respectively. In the regional pasture survey, the soil phosphorus stocks were lower than in the native vegetation, and equal to 9 and 15 kg ha−1 at 0–10 and 0–30 depth layer. The findings of this paper illustrate that land-use changes that are currently common in Brazil alter soil concentrations, stocks and elemental ratios of carbon, nitrogen and phosphorus. These changes could have an impact on the subsequent vegetation, decreasing soil carbon, increasing nitrogen limitation, but alleviating soil phosphorus deficiency.
How to improve access to land and livestock production in synergy with ecosystem conservation? The paradigm occurring in natural grasslands of the Southern Brazilian Campos biome is used to illustrate the dilemma. This paper aims to contribute by addressing the technical bases being used by legislations concerning access to land and incentive to production and their consequences for natural grassland systems. Current policies have a production-oriented focus trying to promote livestock productivity by setting minimum stocking rates to be applied in grasslands. The unexpected results are overgrazing and reduction of natural grasslands, so the dilemma production versus conservation emerges. There is a need for adapting access to land legislations to the new environmental functions expected for natural grasslands, which warrant a conservation-oriented approach according to their multifunctional role. Integrated measures are proposed, which could be helpful in resolving the conflicting compromises regarding the inducement of production and the promotion of natural resources conservation.
Degraded lands have often been suggested as a solution to issues of land scarcity and as an ideal way to meet mounting global demands for agricultural goods, but their locations and conditions are not well known. Four approaches have been used to assess degraded lands at the global scale: expert opinion, satellite observation, biophysical models, and taking inventory of abandoned agricultural lands. We review prominent databases and methodologies used to estimate the area of degraded land, translate these data into a common framework for comparison, and highlight reasons for discrepancies between the numbers. Global estimates of total degraded area vary from less than 1 billion ha to over 6 billion ha, with equally wide disagreement in their spatial distribution. The risk of overestimating the availability and productive potential of these areas is severe, as it may divert attention from efforts to reduce food and agricultural waste or the demand for land-intensive commodities.
By combining crop, livestock and/or forestry activities in the same area, integrated systems (IS) can increase organic matter content in the soil – which favors biomass production and allows for higher livestock stocking rates in pasturelands. The implementation of IS is therefore seen as a promising strategy for sustainable agricultural intensification in Brazil, particularly in Mato Grosso state (MT). However, despite the benefits associated with IS and incentives offered by the federal government to stimulate their dissemination, little is known about these systems or the challenges to implement them, and only a limited number of farmers have adopted IS so far. This paper presents a comprehensive assessment of all IS identified in Mato Grosso by 2012/13, which were mapped and described in terms of their main technical and non-technical features. These findings were combined with farm survey data set to provide a detailed account of the various technologies currently being disseminated, their individual diffusion levels and potential adoption constraints. Results generated through qualitative and quantitative research methods give an overview of IS’ state of the art, reveal farmer perception of such technology and offer insights into the prospects for low-carbon agriculture in the region. The study’s major findings are that IS are present in more than 40 of the 141 municipalities of MT, and the vast majority (89%) involve only crop and livestock. Farmers have adopted three different crop–livestock configurations, depending on their production strategy. Cultural aspects play a major role in farmer decisions to adopt IS, credit provision has not been relevant for IS adoption, and a broader dissemination of IS may occur as land transitions continue.
The large uncertainty in soil carbon-climate feedback predictions has been attributed to the incorrect parameterization of decomposition temperature sensitivity (Q10 ; ref.) and microbial carbon use efficiency. Empirical experiments have found that these parameters vary spatiotemporally, but such variability is not included in current ecosystem models. Here we use a thermodynamically based decomposition model to test the hypothesis that this observed variability arises from interactions between temperature, microbial biogeochemistry, and mineral surface sorptive reactions. We show that because mineral surfaces interact with substrates, enzymes and microbes, both Q10 and microbial carbon use efficiency are hysteretic (so that neither can be represented by a single static function) and the conventional labile and recalcitrant substrate characterization with static temperature sensitivity is flawed. In a 4-K temperature perturbation experiment, our fully dynamic model predicted more variable but weaker soil carbon-climate feedbacks than did the static Q10 and static carbon use efficiency model when forced with yearly, daily and hourly variable temperatures. These results imply that current Earth system models probably overestimate the response of soil carbon stocks to global warming. Future ecosystem models should therefore consider the dynamic interactions between sorptive mineral surfaces, substrates and microbial processes.
One of the primary challenges of our time is to feed a growing and more demanding world population with reduced external inputs and minimal environmental impacts, all under more variable and extreme climate conditions in the future. Conservation agriculture represents a set of three crop management principles that has received strong international support to help address this challenge, with recent conservation agriculture efforts focusing on smallholder farming systems in sub-Saharan Africa and South Asia. However, conservation agriculture is highly debated, with respect to both its effects on crop yields and its applicability in different farming contexts. Here we conduct a global meta-analysis using 5,463 paired yield observations from 610 studies to compare no-till, the original and central concept of conservation agriculture, with conventional tillage practices across 48 crops and 63 countries. Overall, our results show that no-till reduces yields, yet this response is variable and under certain conditions no-till can produce equivalent or greater yields than conventional tillage. Importantly, when no-till is combined with the other two conservation agriculture principles of residue retention and crop rotation, its negative impacts are minimized. Moreover, no-till in combination with the other two principles significantly increases rainfed crop productivity in dry climates, suggesting that it may become an important climate-change adaptation strategy for ever-drier regions of the world. However, any expansion of conservation agriculture should be done with caution in these areas, as implementation of the other two principles is often challenging in resource-poor and vulnerable smallholder farming systems, thereby increasing the likelihood of yield losses rather than gains. Although farming systems are multifunctional, and environmental and socio-economic factors need to be considered, our analysis indicates that the potential contribution of no-till to the sustainable intensification of agriculture is more limited than often assumed.
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe datasets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics and cement production data, respectively, while emissions from Land-Use Change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent Dynamic Global Vegetation Models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). We compare the variability and mean land and ocean fluxes to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ± 1σ, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004-2013), EFF was 8.9 ± 0.4 GtC yr-1, ELUC 0.9 ± 0.5 GtC yr-1, GATM 4.3 ± 0.1 GtC yr-1, SOCEAN 2.6 ± 0.5 GtC yr-1, and SLAND 2.9 ± 0.8 GtC yr-1. For year 2013 alone, EFF grew to 9.9 ± 0.5 GtC yr-1, 2.3 % above 2012, contining the growth trend in these emissions, ELUC was 0.9 ± 0.5 GtC yr-1, GATM was 5.4 ± 0.2 GtC yr-1, SOCEAN was 2.9 ± 0.5 GtC yr-1 and SLAND was 2.5 ± 0.9 GtC yr-1. GATM was high in 2013 reflecting a steady increase in EFF and smaller and opposite changes between SOCEAN and SLAND compared to the past decade (2004-2013). The global atmospheric CO2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that EFF will increase by 2.5% (1.3-3.5%) to 10.1 ± 0.5 GtC in 2014 (37.0 ± 1.9 GtCO2 yr-1), 65% above emissions in 1990, based on projections of World Gross Domestic Product and recent changes in the carbon intensity of the economy. With this projection, cumulative emissions of CO2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO2) for 1870-2014, about 75% from EFF and 25% from ELUC. This paper documents changes in the methods and datasets used in this new carbon budget compared with previous publications of this living dataset (Le Quéré et al., 2013; Le Quéré et al., 2014). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi: 10.3334/CDIAC/GCP_2014).
Dinitrogen fixation is a key process in the N cycle and only carried out by few prokaryotes. Research on dinitrogen fixation includes basic and practical applications: from nif genes to crops, with molecular, genetic, ecological, taxonomic, and agricultural approaches used. Nitrogen fixing rhizobia, which have been used in agriculture for over a 100 years, are excellent research models still leading the knowledge of eukaryote-bacteria symbioses. Other less known symbioses of dinitrogen fixing bacteria are reviewed as well as free-living diazotrophs.
Soil is currently thought to be a sink for carbon; however, the response
of this sink to increasing levels of atmospheric carbon dioxide and
climate change is uncertain. In this study, we analyzed soil organic
carbon (SOC) changes from 11 Earth system models (ESMs) under the
historical and high radiative forcing (RCP 8.5) scenarios between 1850
and 2100. We used a reduced complexity model based on temperature and
moisture sensitivities to analyze the drivers of SOC losses. ESM
estimates of SOC change over the 21st century (2090-2099 minus
1997-2006) ranged from a loss of 72 Pg C to a gain 253 Pg C with a
multi-model mean gain of 63 Pg C. All ESMs showed cumulative increases
in both NPP (15% to 59%) and decreases in SOC turnover times (15% to
28%) over the 21st century. Most of the model-to-model variation in SOC
change was explained by initial SOC stocks combined with the relative
changes in soil inputs and decomposition rates (R2 = 0.88,
p<0.01). Between models, increases in decomposition rate were well
explained by a combination of initial decomposition rate, ESM-specific
Q10-factors, and changes in soil temperature (R2 =
0.80, p<0.01). All SOC changes depended on sustained increases in NPP
with global change (primarily driven by increasing CO2) and
conversion of additional plant inputs into SOC. Most ESMs omit potential
constraints on SOC storage, such as priming effects, nutrient
availability, mineral surface stabilization and aggregate formation.
Future models that represent these constraints are likely to estimate
smaller increases in SOC storage during the 21st century.
The objective of this work was to develop a procedure to estimate soybean crop areas in Rio Grande do Sul state, Brazil. Estimations were made based on the temporal profiles of the enhanced vegetation index (Evi) calculated from moderate resolution imaging spectroradiometer (Modis) images. The methodology developed for soybean classification was named Modis crop detection algorithm (MCDA). The MCDA provides soybean area estimates in December (first forecast), using images from the sowing period, and March (second forecast), using images from the sowing and maximum crop development periods. The results obtained by the MCDA were compared with the official estimates on soybean area of the Instituto Brasileiro de Geografia e Estatística. The coefficients of determination ranged from 0.91 to 0.95, indicating good agreement between the estimates. For the 2000/2001 crop year, the MCDA soybean crop map was evaluated using a soybean crop map derived from Landsat images, and the overall map accuracy was approximately 82%, with similar commission and omission errors. The MCDA was able to estimate soybean crop areas in Rio Grande do Sul State and to generate an annual thematic map with the geographic position of the soybean fields. The soybean crop area estimates by the MCDA are in good agreement with the official agricultural statistics.
No-till (NT) cropping systems have been widely promoted in many regions as an important tool to enhance soil quality and improve agronomic productivity. However, knowledge of their long-term effects on soil organic carbon (SOC) stocks and functional SOC fractions linking soil resilience capacity and crop yield is still limited. The aims of this study were to: (i) assess the long-term (16 years) effects of tillage systems (i.e., conventional – CT, minimum – MT, no-till with chisel – NTch, and continuous no-till cropping systems – CNT) on SOC in bulk soil and functional C fractions isolated by chemical (hot water extractable organic C – HWEOC, permanganate oxidizable C – POXC) and physical methods (light organic C – LOC, particulate organic C – POC, mineral-associated organic C – MAOC) of a subtropical Oxisol to 40 cm depth; (ii) evaluate the soil resilience restoration effectiveness of tillage systems, and (iii) assess the relationship between the SOC stock enhancement and crop yield. The crop rotation comprised a 3-year cropping sequence involving two crops per year with soybean (Glycine max, L. Merril) and maize (Zea mays L.) in the summer alternating with winter crops. In 2005, the soil under CNT contained 25.8, 20.9, and 5.3 Mg ha−1 more SOC (P < 0.006) than those under CT, MT, and NTch in 0–40 cm layer, representing recovery rates of 1.61, 1.31, and 0.33 Mg C ha−1 yr−1, respectively. The relative C conversion ratio of 0.398 at CNT was more efficient in converting biomass-C input into sequestered soil C than NTch (0.349), MT (0.136), and CT (0.069). The soil under CNT in 0–10 cm depth contained ∼1.9 times more HWEOC and POXC than those under CT (P < 0.05), and concentrations of LOC and POC physical fractions of SOC were significantly higher throughout the year under CNT. Considering CT as the disturbance baseline, the resilience index (RI) increased in the order of MT (0.10) < NTch (0.43) < CNT (0.54). Grain yield was positively affected by increase in SOC stock, and an increase of 1 Mg C ha−1 in 0–20 cm depth resulted in an increase in yield equal to ∼11 and 26 kg grain ha−1 of soybean (R2 = 0.97, P = 0.03) and wheat (R2 = 0.96, P = 0.03), respectively. The data presented emphasizes the role of labile fractions in the overall SOC accumulation processes in soils managed under CNT and their positive impacts on the soil resilience restoration and on agronomic productivity.
Inventories of C and N footprints on a landscape scale are essential tools
for estimating C offsets from agricultural emissions. Therefore, the aims of
this study conducted in the subtropical humid ecosystem in southern Brazil
were to: (i) conduct a soil-specific inventory of landscape soil C and N stocks
with reference to soil order, soil texture, and land use/management type; (ii)
estimate accretion rates for soil organic C (SOC) and total N (TN) for areas
managed under no-till (NT) practices management with reference to native
vegetation (NV) based on this inventory; (iii) generate a map of C stocks for
each land use system; and (iv) calculate estimated C offset for the region
through the use of NT compared to conventional tillage (CT). Soil samples
were collected at 324 points to a 1-m depth from the entire region. Soil
texture and duration of NT had a strong influence on C and N stocks. The
average soil C stock across all types of soils for depths of 0–40 and 40–100
cm was 57.0 and 43.0%, respectively. The extrapolation of C stored in the
0- to 40-cm depth based on the NT management for 11 and 20 yr for 1.52
million hectare (Mha) was 9.08 ± 0.62 Tg (1 Tg = 1012 g) representing
11.9% of the C stored in all soil orders. The long-term of C sink capacity by
conversion of arable land from CT to NT in this region is 33.2 Tg of CO2, with
the C offset of 22.5% of all anthropogenic emissions.
Previous research has demonstrated that soil carbon sequestration through adoption of conservation tillage can be economically profitable depending on the value of a carbon offset in a greenhouse gas (GHG) emissions market. However adoption of conservation tillage also influences two other potentially important factors, changes in soil N2O emissions and CO2 emissions attributed to changes in fuel use. In this article we evaluate the supply of GHG offsets associated with conservation tillage adoption for corn-soy-hay and wheat-pasture systems of the central United States, taking into account not only the amount of carbon sequestration but also the changes in soil N2O emission and CO2 emissions from fuel use in tillage operations. The changes in N2O emissions are derived from a meta-analysis of published studies, and changes in fuel use are based on USDA data. These are used to estimate changes in global warming potential (GWP) associated with adoption of no-till practices, and the changes in GWP are then used in an economic analysis of the potential supply of GHG offsets from the region. Simulation results demonstrate that taking N2O emissions into account could result in substantial underestimation of the potential for GHG mitigation in the central U.S. wheat pasture systems, and large over-estimation in the corn-soy-hay systems. Fuel use also has quantitatively important effects, although generally smaller than N2O. These findings suggest that it is important to incorporate these two effects in estimates of GHG offset potential from agricultural lands, as well as in the design of GHG offset contracts for more complete accounting of the effect that no-till adoption will have on greenhouse gas emissions.
The continuous use of plowing for grain production has been the principal cause of soil degradation. This project was formulated on the hypothesis
that the intensification of cropping systems by increasing biomass-C input and its biodiversity under no-till (NT) drives soil restoration of
degraded agro-ecosystem. The present study conducted at subtropical [Ponta Grossa (PG) site] and tropical regions [Lucas do Rio Verde, MT
(LRV) site] in Brazil aimed to (i) assess the impact of the continuous plow-based conventional tillage (CT) on soil organic carbon (SOC) stock
vis-à-vis native vegetation (NV) as baseline; (ii) compare SOC balance among CT, NT cropping systems, and NV; and (iii) evaluate the redistribution
of SOC stock in soil profile in relation to soil resilience. The continuous CT decreased the SOC stock by 0�58 and 0�67MgCha�1 y�1 in
the 0- to 20-cm depth at the PG and LRV sites, respectively, and the rate of SOC sequestration was 0�59 for the PG site and ranged from 0�48 to
1�30MgCha�1 y�1 for the LRV site. The fraction of C input by crop residues converted into SOC stock was ~14�2%at the PGsite and ~20�5% at
the LRV site. The SOC resilience index ranged from 0�29 to 0�79, and it increased with the increase in the C input among the NT systems and the
SOC sequestration rates at the LRV site. These data support the hypothesis that NT cropping systems with high C input have a large potential to
reverse the process of soil degradation and SOC decline.