Conservation Agriculture Research Updates - April 2026

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 10-year study from India compared 2 conventional tilled (CT) puddled transplanted rice followed by either CT wheat or NT wheat with 6 different NT Direct seeded (DSR) rice followed by NT wheat treatments. Details can be found in the abstract or full paper since two treatments also used Sesbania (brown manure) in the system and 2 used an additional mung bean crop. A summary of the results showed that the NT wheat treatments were better than the CT wheat but CT rice had a higher yield than DSR rice. The overall rice-wheat system also was better than the traditional system despite the lower rice yield. Soil fertility, SOC, soil health, GHG emissions, and profitability were better in the CA systems compared to the CT one. The recommended that more research is needed to control weeds, nutrient needs and water management to improve the DSR treatment.

This paper from China compares the Agricultural Eco-Efficiency (AEE) between conventional tillage (CT) and conservation tillage (CA = no-till plus residue mulch) 2000-2020 using various models. Their results overall show that the AEE under conservation tillage is greater than under CT with both systems exhibiting an initial decline followed by an increase over time. However, there was differences between provinces because of contrasting tillage systems an d trends over time. They conclude "The long-term evolution of AEE in individual provinces is shaped by a combination of geospatial patterns, initial conditions, and other influencing factors. These findings provide valuable insights for policy formulation, the dissemination of conservation tillage, and the advancement of sustainable agricultural."

The authors used a mobile, closed chamber system to determine soilborne, greenhouse gas (GHG) emissions from rainfed, farmer-managed CA- and conventional agriculture (CONV), in northern Zimbabwe in on-farm sites that varied in soil fertility and environmental conditions. Field emissions were highest under
warm-moist conditions, which are prevailing for large
parts of the growing season. See the abstract for detailed results. They conclude that "the mitigation effects of CA are highly
site-specific and that CA management practices can have unexpected negative effects on GHG fluxes. The
unimodal rainfall distribution with a long dry winter
period of 7 months and recurrent dry spells in north-
ern Zimbabwe may prevent a net carbon sequestration
under CA management that would have occurred in
the humid tropics.

This paper looks at smallholder farmers issues with tractor mechanization using a survey of 208 farmers, 18 focus groups and 28 key informants in 3 Districts of Zambia. Issues looked included adoption, preferences for ownership, and financing. Tractor ownership revolves around improvement in productivity but also income generation from service provision to other farmers tied to better timing and narrowing planting windows. Differences in gender affect ownership with males preferring individual ownership and females prefer group ownership. Incentives for ownership were best for risk-contingent credit especially if bundled with repair insurance. Barriers to adoption included high maintenance costs' poor access to spare parts and financial issues. They conclude that "successful interventions must be flexible, gender-responsive and tailored to the local context." 

This paper looks at the impact of no-tillage (NT) and conventional tillage (CT) on soil water and physical properties in Romania using undisturbed soil columns from a field experiment that was a continuous cropping system for 8 years with a 4-year rotation (wheat, maize, sunflower and peas). Various soil physical and water measures were taken. The various measurements can be found in the paper abstract. They conclude that the "findings demonstrate that long-term NT improves key soil hydro-physical properties, supporting its integration into sustainable farming systems to balance productivity and environmental stewardship."

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"

The Intergovernmental Panel on Climate Change projects an increase in temperature and the frequency of high-intensity rainfall events in the future in most parts of the world. NT was suggested by the UN missions Gap Report as a potential measure to mitigate the negative effects of climate change. This paper from Texas using the APEX model studies the effectiveness of NT in improving resilience of agricultural watersheds to extreme climatic conditions in comparison to conventional tillage (CT). Results showed that NT was significantly effective in reducing annual soil evaporation, surface runoff, and soil erosion and also maintaining rainfed corn yields compared to CT. During high rainfall events NT also minimized runoff and sediment erosion. The authors feel NT needs to be promoted in these climatic conditions.

This study examined CA practices in a maize-wheat system in India using a 2-year field study with 15 treatment combinations. Their results showed that No-tillage (NT) with residue retention (+R) and phosphorus dose (34.4 kg P ha⁻¹) produced the highest (8.17 t ha⁻¹) maize equivalent yield, system productivity, and net economic return. NT + R also significantly enhanced soil organic carbon, water-stable aggregates, microbial biomass, and enzymatic activities. In contrast, phosphorus application with microbial inoculants under NT without residue (-R) yielded the highest energy use efficiency. They conclude that "integrating CA-practices and optimal phosphorus management enhances system productivity, profitability, and soil sustainability."

This article looks at results from 147 peer reviewed studies from India's major agro-ecological and climatic regions to estimate soil organic carbon (SOC) changes due to Regenerative Agriculture (RA) practices.  RA practices included organic amendments (farmyard manure, green manure, compost, and biochar), no tillage, crop residue retention, and fertilizer management. Results show biochar provided the highest SOC gain. No-till and residue retention had moderate but consistent benefits over time. The most significant SOC gains occurred after 5 years. There was variation across agro-ecological regions, with semi-arid and sub-humid regions showing particularly strong responses. They conclude that RA practices effectively sequester carbon, particularly when applied over longer durations and in regionally adapted combinations.

This paper presents the results of a study to look at CA performance of a cassava-legume cropping system in terms of yield, nutrition, and economics in Northern Zambia. They used a mother and baby trial setup  with 6 cropping systems that combined tillage (flat and bed planting) and legume intercrops (common beans and groundnut) compared to sole cassava. They measured root yield, legume yield, protein yield, energy and economic returns. See the paper for more details, but 3 treatments were planted on the flat under no-till and 3 treatments planted on hand hoed ridges (traditional system for cassava). Results showed cassava planted on the flat especially with legume intercrops under CA did not compromise cassava yield and significantly enhanced legume grain, protein, and energy yields. Economic analyses revealed higher net benefits and return to inputs in flat-planted intercrops, though labour costs were also higher.

This research from Uganda looks at nitrogen fixation with pigeon peas in a maize dominant cropping pattern to investigate the effect of biochar under CA on nitrogen fixation at three sites located in different agro-ecological zones. CA involved minimum tillage with planting basins established by hand hoeing. There were 4 treatments: (1) conventional tillage with crop rotation (CT), (2) minimum tillage with crop rotation (CA), (3) CA and plus biochar, applied in both first and second year (CA+BC+BC), and (4) CA and biochar, applied once in the first year (CA+BC). Grain yield was significantly increased by biochar application in CA systems compared to conventional practices, in all seasons and sites. They conclude that "Biological N2-fixation was positively influenced by biochar application under CA systems".