Conservation Agriculture Research Updates - March 2026

This another report for a long-term experiment (60 years) from the Triplett Van-Doren No-Tillage and Crop Rotation Experiment established in 1962 in Wooster, Ohio, USA that was designed to evaluate the impact of no-tillage and crop rotation on corn and soybean yields. This experiment is conducted on two contrasting soils, one well-drained and one poorly drained. There were 3 tillage practices; moldboard, chisel and no-till with the residue from the previous crop left in the field and 3 rotations; continuous maize, a 2-year maize-Soybean, and a 3 year maize-forage-forage. Crop rotation was the main driver of long-term crop performance, with the most favorable responses observed when forage crops were included in the cropping system at both sites. Note the forage crops contained mixtures with legumes. The paper contains a lot of interesting data. They conclude that " By evaluating long-term trends, we found that no-tillage can be viable even in clay soils under temperate climates when perennial crops are included in the rotation system. Our results demonstrate that longterm crop yields can significantly benefit from the implementation of both practices adopted together in cropping systems."

This is an interesting article that looks at straw biochar's impact on soil fertility, GHG emissions, grain yield, carbon footprint (CF) and net ecosystem C budget (NECB) in an arid region in China based on a 2-year field experiment using 3 biochar quantities and comparing against no biochar. Their results showed that biochar significantly reduced soil GHG emissions, but the highest rate increased methane emissions. Biochar lowered the CF and enhanced the NECB, primarily through increased net primary production and improved soil fertility and crop yields. They conclude that "biochar improved crop yields, NECB, and soil carbon storage while reducing GWP, GHGI, and CF."

Tillage practices have been used by farmers for centuries to prepare soil, manage residues, and control weeds but with consequences for soil health and soil degradation. This global review critically examines and synthesises current research on the impact of various tillage practices like conventional (CT), reduced (RT), and no-till (NT) tillage systems on greenhouse gas emissions (GHG), soil health and agricultural sustainability from scientific papers written on this subject. Some results presented show that CT increases C02 emissions through soil disturbance and oxidation of organic matter, while RT and NT reduce C02 and mitigate N20 and CH4 emissions. NT also enhances water retention and thus drought stress. The author concludes that "RT and NT practices emerge as pivotal strategies for reducing greenhouse gas emissions and advancing agricultural sustainability through improved soil health and water retention."

This paper presents some of the data from  a family farm in Ohio, one of the oldest continuous NT and cover crops adapted farms in Ohio since 1971. The objective of the study was to assess the effects of no-till (NT) management over 0, 6, 20, and 35 years in a rainfed corn-soybean system, incorporating cereal rye as a cover crop, on soil organic C (SOC) sequestration and total N accumulation across different pools. The results show a significant increase under NT compared to conventional for SOC, total N, microbial biomass C, active C, passive C, particulate organic C and N. They conclude that "long-term NT consistently facilitates SOC sequestration and total N accumulation in different pools, with these benefits distributed non-linearly across distinct SOC and total N pools at the 0-15 cm depth and linearly at the 15-30 cm depth in rainfed corn-soybean systems."

This review looks at the latest research on regenerative management strategies and the effects on soil organic carbon content and turnover, since the authors point out the importance of SOC for soil health. Regenerative strategies included CA, rotation, cover crops, organic management, biochar and agroforestry that all improve carbon sequestration. The conclusions are based on 283 studies that had both sort- and long-term field trials. They conclude that their research "outlines the benefits, challenges, and economic prospects associated with these strategies, emphasizing the significance of improving SOC management to promote soil sustainability and mitigate climate change consequences."

This article from China starts by saying short term no-till increases bulk density, reduces total porosity and microporosity that affects aeration. Their goal was to see if over time NT can overcome these negative effects. They used a 4-year field experiment that used rotary tillage (RT), subsoiling (SS) and NT and evaluated soil gas diffusivity and water retention across a range of soil matric potential. They used Undisturbed soil samples (0-40 cm depth) using X-ray Computed Tomography (X-ray CT) to characterize pore structure. Results showed that NT reduced total soil porosity and macroporosity in the upper 30 cm compared to RT and SS but increased plant-available water content. NT also maintained higher gas diffusivity under wet conditions by forming irregular-shaped pore networks that increased specific diffusivity compared to RT and SS. They conclude that "NT effectively balances soil air-water conditions at higher moisture levels despite initial compaction, underscoring its potential waterlogging resistance."

This 2-year on-station experiment from IARI, India looked at the impact of conventional (CT), CA and Organic (OA) on pigeonpea grown in a PP-wheat system. CA 1, 2 and 3 were on permanent narrow beds (PNB), broad beds (PBB) and flat (PFB), respectively. All 3 CA treatments performed better better than CT and OA for several parameters. CA2 had greater plant height and dry matter accumulation in both years. All CA treatments had better nodulation, nitrogen fixation and soil health. Yields were better in the 3 CA treatments with CA2 to highest compared to CT and OA. Cost of cultivation was a little higher in CA treatments than CT but gross returns were higher. They conclude that "CA enhances pigeonpea productivity and farmers' income in the upper and middle Gangetic plains of India.

This paper from Italy looks at using tillage radish (TR) in place of fallow to see if it improves soil health. The studied the effects of this cover crop on soil health indicators related to C, N and P cycling in two different climatic conditions using CA practices. Biomass and P uptake by the TR were higher in one site than the other that also had higher levels of SOC in the top layer of soil. TR increased SOC, labile organic C, soil P test, and microbial biomass C, N, and P, but amounts varied by location. They conclude that "TR's positive effects on some soil health indicators related to relevant ecosystem services, particularly C storage, microbial biomass, P mobilization and recycling, and N balance, with site-specific variations depending on pedoclimatic conditions."

This paper from Brazil assessed the carbon dioxide equivalent (CO₂e) emissions based on soil organic carbon (SOC) stock changes in 1-m depth by plow-based tillage (PBT) and the mitigation potential through a no-till system (NTS) across 26 sites in the Cerrado biome and 37 sites in the Atlantic Forest biome. The tropical climate zone had significanly less emissions than the sub-humid climate zone. Thier results showed that "adoption of NTS demonstrated a high capacity for offsetting CO2 emissions, achieving 5.40 Tg CO2e in the tropical equatorial zone (recovering 98 % of the total emissions), 2.57 Tg CO2e in the tropical central zone (68.7 %), 2.67 Tg CO2e in the subtropical humid zone (83.2 %), and 2.88 Tg CO2e in the subtropical temperate zone (68.6 %). 

This article describes the history of California's Conservation Agriculture Systems Innovation (CASI) that increased the sustainability of agriculture in the San Joaquin Valley of California, by reducing soil erosion, conserving soil moisture, using systems thinking, creating farmer networks, advisors, and researchers since 1998. It used CA management that included reducing soil disturbance for better soil structure and biological activity, retaining biomass on the soil to support soil life, and diversifying crops to enhance biodiversity. They calculate that CASI involves more than 2200 farmers and private sector, university, public agency and environmental groups as partners. The paper describes the benefits of CA in maize, small grains, vegetables, cotton, beans, and melons. They conclude that "reducing soil disturbance for better soil structure and biological activity, retaining biomass on the soil to support soil life, and diversifying crops to enhance biodiversity."

This research looked at long-term adoption of residue retention on soil-water and temperature for wheat grown under CA in both a field experiment and crop model simulation using the APSIM (Agriculture Production System Simulator) model. Two tillage practices were NT + Residue retention (NT+R) and CT with residue incorporation (CT+R). The results indicated that the model accurately simulated crop phenology, leaf area index, above ground biomass, and grain yield under both tillage treatments. Soil water content, transpiration and drainage were higher in NT+R compared to CT+R. Evaporation and soil temperature were higher in CT+R. The authors were happy with the APSIM model for identifying the effect of tillage and residue on wheat yield components. 

This paper starts out by saying that in Sub Saharan Africa (SSA) tillage and burning of residues is mostly used that causes soil erosion. Maize is also the major crop in smallholder diets. They used the APSIM model to simulate the productivity and protein yield of a variety of intercropping systems involving three crops (maize, cowpea and pigeonpea) under full CA practice relative to conventional tillage (CV) with the same intercropping system. The baseline scenario used daily climate data from 1997-2015 in Northern Mozambique. The results are given in the paper but the Authors conclude that "although under the CA system, there were ng declines in grain yields nevertheless, protein yields and overall productivity remained consistently higher under the CA system.

This review assesses the effect of CA management on soil biological, chemical and physical properties. Results show that CA improves soil structure, enhances soil organic carbon sequestration, promotes microbial activity, increases water-use efficiency, and reduces erosion and nutrient losses. The paper also reports on environmental, economic, and social benefits of CA that include biodiversity conservation, reduced greenhouse gas emissions, improved yields, and increased food system resilience. They also look at the the socioeconomic conditions, institutional frameworks, and policy interventions that shape CA adoption and impact and the CA research gaps and future of CA directions.

This research from NW India analyzed data from a 17-year long term experiment that concentrated on crop establishment, tillage and residue management in a rice-wheat system. This cropping system and region of India is impacted by residue burning and GHG emissions. The experiment had 5 scenarios from the traditional system of puddled transplanted rice followed by tillage before planting wheat with all residues removed (Traditional) to NT direct seeded rice (NTDSR), NT wheat (NTW) and 1/3rd residue retention (RR) of both rice and wheat. Among the scenarios the NTDSR-NTW-RR one achieved the highest carbon management index across both the soil layers, indicating a reduced need for carbon management due to higher TOC  compared to the traditional system. They conclude that "reduced or no tillage combined with residue retention in RWS holds substantial potential for increasing carbon sequestration, reducing net GHG emissions, and lowering carbon footprints. Additionally, this practice offers an alternative to crop residue burning, a significant contributor to air pollution in the western IGP."

Manual methods of farming are common in Africa and also in Zimbabwe where this paper was written. It measures the fuel consumption needed to use a two-wheel tractor to relieve the drudgery of manual farming in this country. This is important for calculating the cost of mechanizing agriculture and GHG emissions. This study measured fuel consumption for 2-wheel tractors in direct seeding for sorghum and pearl millet crops in sandy soils at varying speeds of operation. The information in this paper can be used by farmers and other operators of 2WTs for planning the fuel quantity and budgetary requirements.

Burning of crop residue by farmers so they can easily prepare land for the next crop is common in India that creates a health issue by polluting the air. It also contributes to C02 and black carbon emissions that then affects climate change negatively. This paper points out that the introduction of the Happy Seeder from Australia allows farmers to sow the next crop without removing the previous crop residue and so is an effective alternative to burning. However, the supply of this seeder is limited and this delays planting of wheat after rice that results in lower wheat yields. This paper looks at how this predicament can be resolved in India through Government policies. 

This paper describes a way to map accurately the area and fields in Belgium that practice CA management. They point out that monitoring of CA adoption is usually dependent on farmer declarations or field inspections that are not very accurate. In this paper 247 fields using CA in 2020-2021 were used to develop a classification model for predicting CA by combining remote sensing and census data. The census data provided the data for annual crops and cereals in the rotation. The paper explains what remote sensing was used to measure the extent of soil cover, soil disturbance, to construct a classification model distinguishing fields under conservation from those under conventional practices. Their results showed 15.5 % (2875 fields) out of 18,516 cropland fields can be classified as conservation agriculture. These fields tend to adopt non-inversion tillage and have diverse crop rotations.

This interesting paper reviews through 150 peer-reviewed studies published from 2013-2024 the impacts of rotation and cover crops, the former an important pillar of CA and the latter a valuable addition to CA for weed control and providing surface mulch when it is possible to include. They identified papers that identified impacts by monitoring and modeling. Results show that rotation can increase yields, enhance soil moisture retention, fertility and mitigate pest, weed, and disease pressures while improving environmental sustainability. The paper also reviews modeling frameworks to simulate rotation practices. The paper discusses agricultural effects, environmental and soil health impacts, modeling and monitoring approaches, and limitations and future research directions. They conclude that "these insights provide actionable guidance for farmers, extension agents, and policymakers to design more resilient and sustainable cropping systems tailored to local environmental and economic conditions."

This paper from Brazil looks at the role of cover crops to improve soil fertility, plant nutrition and soybean yield in the Cerrado area in a dryland area. There were 8 cover crops, and fallow preceding soybeans grown in the off-season. This area had cultivated soybeans under no-till for 10 years. They measured the biomass of the cover crops, but also soil chemical and biological properties, soybean foliar nutrients, yield and quality. Data can be found in the paper and abstract. They concluded that "Cover crops improved soil fertility while increasing soybean productivity, thus being an effective strategy for the achievement of sustainable soybean production."

This article from China looks at the impact of adoption of CA on income. They surveyed 922 households in 5 provinces in 2023. The income effects vary by the adoption status of different CA practices. Farmer time allocation affects CA technologies adoption. Farm work is the main mediating variable, while off-farm work plays a moderating role between the yield effect and income. They write "The complex technology adoption chain inhibits farmers from increasing production and income, while the farmers' jobs in the non-agricultural sector have reduced this impact to a certain extent." They suggest that policies need to enhance technical training for farmers, improve markets, and provide more mechanized services in order to increase adoption.

This is another article in this February newsletter from South America that provides very long term data on CA from a research experiment that considered 5 treatments representing agricultural systems relevant to Paraguay and assessed after 32 years. Treatments in a wheat-soybean system included conventional tillage (CT), reduced tillage (RT), and no-tillage (NT1). In addition, two diversified no-tillage rotations with increasing adoption in the region were included: NT2, composed of black oat–soybean, wheat–soybean, and black oat–soybean; and NT3, consisting of wheat–soybean, vetch–maize, and black oat–soybean. These crop sequences were implemented continuously in three-year cycles over the 32-year study period. The study focused on nutrient stocks, however, consistent relationships between pH and nutrients were observed while pH remained below the minimum threshold recommended for the regional commercial crops . They conclude that "diversified no till farming conserves fertility in low input contexts, but the benefits are limited due to soil acidity. Finally, integrating periodic soil diagnosis with amendments, particularly liming, offers a practical pathway to sustaining production in Paraguay."

This is another article from the Central Valley of California that assesses 20 years of conservation agriculture management that looks at soil physical, chemical and structural properties comparing reduced tillage with cover crops with conventional tillage without cover crops. In brief, the CA management achieved dynamic equilibrium characterized by fundamental shifts in carbon stabilization pathways. Water stable aggregates also exhibited 136% greater stability with CA than with CT. This paper discusses the implications of these differences. They conclude "This mechanism shift represents a new soil system equilibrium that maintains enhanced functionality and continued carbon sequestration potential in Mediterranean agricultural systems."

This paper from North America synthesized data from 30 meta-analyses to comprehensively assess the impacts of the no-till (NT), reduced till (RT,) and mixed NT+RT on crop yields and GHG emissions. Results showed that the yields of wheat, maize, rice, fibers, cotton, and cereals were not significantly affected by NT, while the yields of soybean, oilseeds, and legumes were enhanced by NT. NT did not influence soil CO2 emissions, and none of the tillage treatments influenced soil CH4 emissions. However, NT increased soil N2O emissions whereas RT and NT+RT had no significant effect on soil N2O emissions. They suggested that the varied impacts of tillage can be attributed to soil properties and practices like crop residue management, irrigation type, and nitrogen rates. 

This paper discusses the pros and cons of the term Regenerative Agriculture in Europe. They looked at 849 actors web sites and interviewed 131 farmers who use this system from 5 European countries. They mapped actor types, locations, sizes, and promoted themes (e.g. biodiversity) and practices (e.g. no-tillage). Their results suggest that RA originated as a grassroots approach to farming that was co-opted by non-farming actors around 2020. Since 2021 the number of RA farmers has declined as the focus shifted from farming to marketing driven by multinational companies. Interaction with Policy makers was limited and most of the actors were urban-based NGO's. Among nearly 5000 cited practices, cover cropping and crop diversification dominated. They concluded that "the burden of proof for regenerative agriculture to be sustainable lies in its ability to regenerate the environment—until then, its impact remains uncertain."

This review from Zimbabwe reviews the Pfumvudza/Intwasa initiative that has been promoting conservation agriculture (CA) practices among smallholder farmers in this country. In terms of policy this project provides guidelines for implementation, resource allocation, and support systems. The review examines the role of government policies and institutional frameworks in sustaining CA practices in Zimbabwe using a literature review analyzing peer-reviewed articles, policy documents, and government reports published between 2000 and 2024. Results both strengths and limitations. The authors mention that policies promote conservation agriculture, inclusive participation, and resource distribution, but challenges such as inadequate institutional coordination, limited extension services, and funding constraints limit the success of this program. The report recommends "policy harmonization, targeted investments in extension services, and the promotion of equitable resource distribution. Additionally, leveraging technology for monitoring, enhancing market access for smallholders, and fostering public-private partnerships will support the scalability and sustainability of this project"