Conservation Agriculture Research Updates - August 2025

This study assessed the 10 year effect (experiment started in 2012) on CA practices on soil physical properties in a sub-humid area of South Africa. It had 16 treatments and 3 replications. They looked at CA vs CT, 4 rotations, and plus and minus residue cover. They collected soil samples from 3 soil depths in 2023/2024 for various soil physical measurements. Their results showed that tillage practices had a greater impact on bulk density (BD), porosity (phi) and aggregate stability (AGS)/ stability index (SI) compared to crop rotations and residue management. Rotations with soybeans had lower BD values that ones without soybeans and the authors suggest this maybe the result of faster soybean residue decomposition than maize and wheat residues. R+ plots had higher gravimetric water content and higher volumetric water content than R- plots, due to the substantial amount of SOM returned by residue decomposition. 

This paper suggests that CA is often though to under perform in high rainfall areas like Northern Zambia. This paper evaluates a long term (9 year) study in this area of maize cropping systems and rainfall variability on yield, , soil pH, and SOC. Three CA systems were compared to 2 conventional systems. Results showed despite rainfall variability across years, CA systems did better than conventional systems especially in low rainfall years. However, bed planted traditional systems out performed CA systems in high rainfall years. However over time yield declined faster in the conventional system than the CA systems as nutrients declined. They conclude that CA systems can improve maize yields in high rainfall areas but strategies are needed to mitigate waterlogging  after heavy rain and sustain soil fertility.

This research is conducted in the Mediterranean climate region of South Africa where the livestock sector constitutes a substantial contributor to the regional economy and where CA is integrated with livestock. Crop rotation with small grains and canola are combined with alfalfa and medics to supply feed for sheep. But this system raises concerns about livestock-crop competition but also nitrogen flows, on-farm nutrient balance, water pollution, soil acidification, biodiversity loss and impacts from climate change. This paper suggests that CA integrated agricultural systems serve as a buffer against environmental degradation caused by conventional agricultural systems.

This paper provides an overview of the science and farmers’ expectations of conservation tillage (CST) in six European countries, including Croatia, Serbia, Hungary, Slovakia, Czech Republic, and Poland where traditional intensive tillage results in soil erosion, loss of SOM, and soil degradation. This review looks at the adoption on CST in these countries and looks at the current progress and future prospects. CST provides adequate soil cover, minimizes erosion, and encourages biological activity and organic matter accumulation that results in improved soil productivity and resilience against additional degradation and climate variation. Results showed a high level of diversity in readiness and willingness to accept, as well as different levels of knowledge about the adoption of CST, but adoption is increasing and this represents a key way to slow soil degradation and adapt to climate change.

Wheat has seen remarkable productivity gains in NW India through increased input use and intensive cultivation. But soil degradation indicates that this essential food security region of India is becoming less economic and sustainable. This paper looks at data from 3928 wheat fields and used to assess multiple sustainability indicators including yield gaps N-use efficiency, profitability, and GHG emissions. Stochastic frontier analysis was combined with simulated potential yield (Yp) data to identify the causes of wheat yield gaps in the region The most important management practices governing the field classification included the crop establishment method used for the previous rice crop, the number of tillage operations, residue retention, and the N fertilizer rate for wheat.

This review explores a number of soil and water conservation practices, organic amendments, and agroforestry for specific soil types (7)  for the many diverse agroecological zones in Africa. In particular it looks at the role of soil through physical management to ensure resilience to climate change using long-term studies that are essential for improving soil structure, moisture retention, reducing erosion and enhancing SOM. However, adoption of these practices that improve resilience to climate change faces challenges due to diverse soils and ecologies, barriers to adoption and resource constraints. The authors advocate an integrated approach combining local expertise with scientific advancements and appropriate policy interventions.  to achieve the needed resilience.

This paper from Mexico looked at the the impact of conservation tillage (CT) versus intensive tillage (IT) on bacterial communities from experimental platforms that had practiced these three different tillage options for 25 years. The three tillage options were IT, CT and reduced tillage (RT) with residue with and without for each tillage practice. CT or conservation tillage showed higher species diversity and beta diversity while IT showed higher richness. IT results were grouped in the same phylum range whereas CT had a different range. CT also improved the soil physicochemical properties. Although not mentioned in the abstract, zero tillage and reduced tillage systems  led to the development of copiotrophic ecological niches, predominantly attributed to heightened organic matter levels stemming from the decomposition of agricultural residues and wastewater irrigation.

This review looks at several ways to improve soil physical health. They define this as physical, chemical and biological characteristics. It includes structure, porosity,  and water retention. They include  soil management like CA, cover crops, and organic amendments. They also suggested precision farming and remote sensing as ways to monitor and manage soil health. They found they had constraints to undertake this and so recommend that future efforts focus on multidisciplinary research to better understand complex relationships.

This interesting article looked at 650 scientific papers to provide an analysis of global scientific production on Conservation Agriculture (CA) and its relationship with climate change mitigation. There has been a significant increase in publications in the last 30 years on sustainable. agricultural practices including key themes on no-tillage, SOC, and GHG emissions. Results indicate that CA research is increasingly focused on its potential to mitigate climate change, particularly through practices like no-tillage, vegetative cover, and crop rotation. This analysis underscores the importance of CA in addressing climate challenges and offers insights into emerging research areas, such as regional adaptations and the long-term effects of no-till systems. The findings aim to guide future research and policy development in sustainable agriculture and climate mitigation. 

This maize-wheat experiment in India evaluated various agronomic practices productivity, profitability, energy use efficiency, and greenhouse gas (GHG) emissions and to identify climate resilient and sustainable agronomic practices for this important cropping system.The experiment utilized different crop establishment methods and nutrient management options. Permanent raised beds (PRB) with residue (R) significantly enhanced system productivity (+23.2 %) over conventional tillage (CT) without residue, with higher system production and monetary efficiencies. They conclude that adopting CA practices enhances productivity, profitability, and environmental sustainability in M W system. 

This paper used the Agricultural Production Systems Simulator Model (APSIM) to evaluate how different tillage methods and straw return practices affect maize yields and SOC under future climate scenarios in China. They had 3 tillage methods, conventional (CT), rotary (RT) and no-tillage (NT) and 2 residue treatments , with and without. The model showed that under climate change scenarios NT showed the highest yield and SOC in the 0-20 cm soil layer with or without residue.  For different straw return methods, SOC decreases when the straw is removed but increases when the straw is returned in both scenarios. They conclude NT and residue management can mitigate long-term climate change impacts on maize yields and soil health

 oks at how conservation based practices regulate pathways of SOC formation and stabilization. They sampled soils in the 0-20 cm layer from conventional (CT), rotary (RT) and no-till (NT) practices in an experiment using these tillage practices for 17 years in China. Their results showed that NT compared with CT increased SOC by 33% for particulate organic matter (POM) and 61% in mineral associated OM in the 0-10 cm layer. The paper has  more data on this experiment.  They conclude from their study that conservation agriculture alters the SOC amounts and biogeochemistry in soil functional fractions, which could provide some mechanistic insights into soil C accrual pathways and persistence in temperate agroecosystems.

Low soil fertility, water holding capacity, and climate change threatens dryland farmers especially on sandy soils. This paper looks at sorghum with CA to address this problem but also looking at genotype, planting time, tillage and rotation on a sandy, dryland soil in South Africa. Tillage was CT and NT, planting early and late, and rotating wit cowpea or monoculture sorghum. Early planted sorghum yielded more than late planted. NT had higher SOC, available P and K than CT. They conclude that results show that positive effects of early planting and NT on sorghum grain and dry matter yields, while effects on soil properties were greater during the season with higher rainfall, with no effects of cultivar and rotation on this infertile sandy soil.

This paper looks at the success of CA in high rainfall areas of Northern Zambia from a long term (9 year) experiment to determine if CA is a viable system under these conditions. The experiment looked at three different CA systems, basins, animal ripped line planting, and dibble stick planting and compared with conventional inversion tillage and ridge and furrow tillage. Yearly rainfall over these 9 years was variable. The 3 CA systems mostly did better than the 2 conventional systems, especially in medium to low rainfall years. But ridge and furrow systems did better in high rainfall years because of better drainage, but overtime, yields declined because of nutrient decline. They conclude that CA systems can be recommended in these high rainfall areas in management systems to overome waterlogging and sustain soil fertility are included.

This paper looked at longterm soil ecosystem status of farmers adopting CA under two different management and environmental conditions in Southern Africa using conventional systems and grazed grasslands as checks. Various soil chemical, physical and biological properties were measured. At one of the sites pasture and conservation agriculture systems presented elevated organic matter content and microbial activity due to continuous organic cover and minimal physical disturbance and essentially healthier soils. In the second site differences between conservation agriculture systems were strongly associated with soil texture differences, influencing organic matter and respiration rates. This means that tailored systems to complement on-farm options and local conditions are needed.

This paper on Africa highlights and discusses the current problems which include soil erosion, desertification, nutrient imbalances, acidity, salinization, deforestation, and soil compaction. The second part looks at the problems of soil and agricultural productivity and  human health, which resulted in loss of fertile land and biodiversity, increased greenhouse gas (GHG) emissions, nutrient depletion, loss of ecosystem services, malnutrition, and other human health issues. The third part proffers potential solutions to tackle soil degradation in Africa. They conclude that iintegrated approaches that promote sustainable soil management, such as conservation agriculture, crop rotation, agroforestry, afforestation, organic farming, and community engagement, would have a significant impact in resolving the menace of soil degradation.

This study examined types of adaptation strategies implemented by males/male-headed households and females/female-headed households and how these influence food security.They used a household food insecurity Access Prevalence (HFIAP) and a probit model to assess food security and adaptation strategies. They collected data from 521 household in Kenya and 1,049 adults. Many of these respondents mentioned reduced and less predictable rainfall resulting in longer droughts that affected productivity. The respondents used three adaptation strategies to  address the above problems: CA (69%), changes in planting dates (49%) and planting drought tolerant crops and varieties (47%). More male dominated households that female used all 3 strategies. Access to credit, non-farm income, types of crops grown, and weather perception variables were the important determinants of adaptation. They conclude that the three strategies worked to increase food security for male dominated households but not female dominated households who are more susceptible to climate change and suggest policies are needed to help female headed families.

This report used a multilocation and multiyear trials to compare direct seeded (drilled and broadcast) with puddled transplanted (PTR) Aus (spring) rice using three rice varieties and 3 landscape positions (high, high-medium and lowland) in 3 different Districts in Bangladesh. Measurements included yield, profit, energy use efficiency and and productivity, Global warming Potential (GWP), and emissions. They conclude that DSR is more environmentally sound and economically viable and a climate-smart system and more suitable for highland and medium highland landscape positions. The paper did not mention issues of weed control in the abstract. This is probably a major issue when adopting DS rice.

This paper uses the term "incorporated" for residues in CA but not sure if they mean surface applied or incorporated into the soil. I think they mean used as surface residue. They looked at GHG emissions using different amounts of nitrogen. They collected soil samples from fields after 6 years of 0, 187 and 337 kgN/ha; low, medium and high N. Straw was with and without. Adding straw significantly increased N20 and C02 emissions compared to those with out straw. Medium N had lower N2) emissions compared to high N and increased C02 emissions compared to 0N with straw. In conclusion, straw amendment increased GHGs and diminished the risk of losing mineral N by enhancing its turnover. Straw with medium-N soil could mitigate the greenhouse effect and improve the N and carbon (C) balance in farming systems compared to low- and high-N soils. 

Cover crops are becoming popular especially in countries where there is space to grow a CC. However, there is a need to terminate a CC so it doesn't affect the growth of the following cash/food crop. The following are three common ways to do this: winter frost, herbicide chemical treatments, or mechanical methods. This paper looks at possible mechanical systems for termination. They developed a modular multiple tools prototype to evaluate different tools that looks at them individually and together. 3 tools were evaluated: tine cultivator, disk harrow and crimper roller and then tested with a vetch and barley CC's. The best combination was the disk harrow 15 degrees, used alone and in combination with other tools considered (crimper roller and tine cultivator for barley, crimper roller for vetch) with a termination rate greater or equal to 85%.

As the global population rises, ensuring food security through sustainable agriculture practices has become imperative to achieve sustainable development goals (SDGs). This research review endeavours to add to the discourse surrounding the obstacles and possibilities in shifting towards sustainable agriculture globally, exploring the roles of SDGs and traditional farming practices.Their findings underscore the urgent need for a holistic and integrated approach that aligns with the SDGs, fostering resilience, environmental stewardship, and equitable development within the global agricultural sector.

This article aims to better understand the interaction of no-till and residue management affect the soil microbiome. Soil was collected from a long term field trial that had CT and nt and plus and minus residue. Stubble management markedly altered both the taxonomic and functional composition of the prokaryotic community, the addition of stubble caused a significant increase in Proteobacteria, but a decrease in Chloroflexi compared with no stubble. Stubble retention increased the availability of carbon resources in the soil, resulting in a higher proportion of genes functional for metabolic activity and plant–pathogen interactions. However, tillage practice did not influence the structure or diversity of the soil prokaryote community.

This paper collected data from 89 experimental sites globally and 10 from China. Their study evaluated potentially mineralizable carbon (PMC) using first-order kinetic fitting, and specific PMC (SPMC, PMC/SOC) to elucidate patterns of SOC mineralization under CA and its moderation by climatic, environmental, and soil factors. The paper describes the detailed results. They proposed a conceptual model highlighting nonlinear relationship between stable SOC pool and SOC, emphasizing how the relationship between C sequestration and emission reduction can be optimized under crop rotation. They also suggested future research look into microbial pathways in SOC mineralizationand their role in balancing mineralization and sequestration.

This paper from China looks at remote sensing to measure the important need for crop residue cover in CA that protects the soil from erosion and enhances soil health. Accurate and rapid mapping of crop residue covered crop land (CRCC) is important for monitoring tillage practices. To overcome problems with measuring residue this study proposes a crop residue covered spectral index (CRCSI) based on spectral and separability analysis of Sentinel-2A images. Three study cases in different seasons and regions were selected to develop and assess the performance of the CRCSI that showed the reliability and superiority of the index from three aspects: visual evaluation, separability analysis and CRCC mapping results.