Conservation Agriculture Research Updates - March 2026

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 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 article explores the interaction of genotype (16 cold tolerant) and tillage (3) for chickpeas in dryland areas of Iran over three cropping seasons. Tillage treatments were moldboard with residue removed (CT); minimal tillage (MT) with a chisel plow with residue; and no-till (NT) with residue retained. Results were positive for no-till + residue with increases in SOC, potassium, phosphorus, nitrogen and soil moisture compared to the start of the experiment. There were differences in performance between the different genotypes with some better with no-till and others with MT and others with CT. Chickpea genotypes cultivated under the NT system demonstrated superior performance (41%) in comparison to those grown using conventional tillage (CT) practices during the third year.

Excessive tillage of soils in semi-arid Mexico has resulted in severe soil degradation, physical and chemical. The aim of this research was to evaluate how CA can reverse this issue over the long term (25 years) in a maize-triticale rotation under irrigation comparing conventional tillage against CA. They measured various soil physical properties and grain and forage yields. In 18 of the 19 soil quality indicators were higher for CA compared to CT. The highest estimated sustainability was 85% for CA, compared to 59% for CT. CA had greater structural stability with higher porosity values and lower bulk density, important factors for soil structure and crop yields.

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 experiment from dryland cotton areas of India looked at the impacts of tillage and weed management on soil quality index and system yield in a cotton-maize system. Treatments included various combinations of conventional tillage (CT) and no-till (NT) in cotton and maize with and without the legume Sesbania rostrata.Weed treatments (sub-plots) included use herbicide (H), herbicide rotation (HR), integrated weed management (IWM), and one hand weeding (HW). The experiment was run for 3 years. They measured 40 soil variables for soil chemical and physical properties. The soil quality index and yield increased by 23% and 52%, respectively for the NT with cotton + Sesbania rostrata residues–NT with maize + cotton residues–NT with Sesbania rostrata + maize stubbles compared to the farmer practice that used CT and no Sesbania. They conclude that NT for Cotton, Maize and Sesbania with residue retention and IWM had better soil quality and yield.

This paper did an extensive literature review to look at the biodiversity of pulse systems and ecosystem services using different management systems in terms of food/feed provision and soil health.  Most studies examined soil quality, especially chemical quality, followed by grain yield. Very few studies surveyed biodiversity, most of which used arable flora as an indicator. Their results and conclusions showed significant positive impacts with organic farming on biodiversity, no tillage on soil health and yield, and rotations on yield.

This paper from South Africa explored soil fauna, physico-chemical properties, soil health, and multi-functionality management in 4 different land uses: Conventional (CT), livestock integrated (LA), conservation agriculture (CA) and natural grassland. Results showed that CT favored some nutrients, but soil of both LA and CA had physical and chemical properties indicative of good soil quality like low compaction, low C:N ratio and stable aggregates. Soil fauna abundance was more responsive to management than diversity. Ct where tillage is used had the lowest soil fauna and soil quality due to its disruption compared to no-tillage. They conclude that implementation of sustainable soil management practices that improve soil physical and chemical status will be beneficial for productivity but also for the promotion of important soil fauna, better soil quality and ecosystem multi functionality.

This article looks at how nature manages resources and describes management of a living soil and its productivity using nature's laws to guide crop management. It contends that although tillage was considered necessary for agriculture it is now considered as the cause of soil degradation and violates the laws of nature. Soil tillage over time destroys soil biological, chemical, physical and hydrological properties resulting in soil degradation and lower yields. CA systems that include much reduced or no-tillage with surface mulch and crop rotation on the other hand emulate nature.  and offer farmers, both large and small, productivity, economic and environmental benefits. Te authors conclude that application of CA based management will be needed to reduce the impact of climate change on future food security.

This global review compiles data on the impact of cereal residues on soil health, residue management, residue removing issues, and differences in SH between incorporation or retention on the surface using 113 peer reviewed articles. The review found that both residue retention and incorporation affected soil physical, chemical and biological properties important for soil health.

This paper is from Austria and the objective is to evaluate the soil physical, chemical, and biological effects of 3 different tillage regimes -- conventional (CT), mulch tillage (MT) and No-till (NT) over the long term (1994-2021) sampled in 2002 and 2021. They assessed soil health indicators in the 0-20 cm soil depth (CT soil layer) and below 20 cm. A  “Soil Management Assessment Framework” (SMAF) procedure was applied to assess and compare soil quality using the Soil Quality Index (SQI). MT and NT enhanced soil quality, predominately soil organic carbon (SOC) and soil physical indicators (e.g. water holding capacity, coarse pores). SOC in the 0-20 cm depth increased significantly in NT compared to CT.

This review looks at the challenges of meeting food demands in South Asia complicated by climate change. They contend that CA can help resolve challenges of soil health, climate change, water scarcity, pollution, profitability and human health. This review uses published literature to look at how CA affects SOC and therefore soil health, carbon sequestration and GHG emissions. The results from several studies show CA increased SOC and improved soil health mainly in the surface layer. CA also made a positive impact on nutrient availability. The present gaps in knowledge of soil health assessment and research to fill the gaps are also included in this chapter.

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 review from Romania highlights the importance of soil health for sustainable agriculture and identifies practices that result in improved soil health that includes, physical, chemical and biological properties. The explored rotation, cover crops, no-till, CA, and use of organic amendments to achieve SH properties that includes better soil structure, increased organic matter and biological diversity. Increasing soil organic carbon (SOC) is vital. Their results show that CA is a better option to restore soil health than conventional systems although they mention that this topic is still controversial among scientists and farmers. 

The authors mention that there are 3.5mha of CA in India but little data on the effects of CA on soil nutrient dynamics like N, P, and S. They have a nine year study on these nutrients in a maize-wheat cropping pattern that compares CA with conventional methods. Results show that CA and N addition significantly enhanced various soil chemical properties and microbial biomass compared to CM for N, P and S and concluded that "These findings contribute crucial knowledge for sustainable development by offering valuable perspectives on N, P and S management strategies."

This paper from Southern India assesses the impact of different tillage and weed management practices on soil nutrient stratification ratio (SR), carbon sequestration rate (CSR), carbon management indices (CMI), carbon retention efficiency (CRE) and monitor the grain yield of maize after three-years in CA with a cotton-maize-Sesbania cropping system. There are 3 tillage practices; CT cotton and maize, no sesbania = farmer practice; CT cotton- NT maize-ZT Sesbania; and NT for cotton, maize, and sesbania. 4 Weed treatments were herbicide, herbicide rotation, integrated weed management, and hand-weeded control. They conclude that NT plus residue retention and herbicide use would be a viable way to imporve soil health and imptove productivity of the cotton-maize-sesbania system.

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 15 year long-term experiment from Haryana State in India using a rice-wheat system was designed to measure the impact of 15 years of tillage and residue management on the soil quality index (SQI) and yields. There were treatments: 1. CT without residue (-R); CT with +R incorporated; Reduced tillage (RT) with -R; RT +R incorporated; NT -R; and NT +R left on surface. Soil measurements included various physical, chemical, and biological properties. Results showed that NT+R had the lowest bulk density and soil penetration resistance at the surface soil leading to better water infiltration. Also improved SOC, and microbial activities. Wheat yields were higher for NT + R, but lower for rice yields. This was related to using direct seeded rice and probably having more weeds than in the transplanted conventional rice. 

This paper from India looked at the effect of CA and N management on soil N, P, and S release and the enzymes involved. The results showed that CA significantly enhanced the mineral N, Olsen P and CaCl2-S release and the soil enzymes involved compared to CT + R plots. They conclude that CA alongside optimum nitrogen management enhances the soil enzymatic activities and nutrient mineralization that results in higher crop output while maintaining soil health.

This study collected soil samples from paired farms that had used CA or conventional tillage (CT) and looked at tillage effects on physio-chemical properties including SOC by soil depth. SOC was higher in CA soils. But higher SOC was measured at depths of 0-10 cm compared to 10-30 cm under CA. In fact, soil depth had significant effects on most soil properties compared to tillage. The paper concludes that CA improved total SOC and its associated fractions, a finding relevant towards understanding effects of land management on carbon storage. However, challenges of competing residue use as feed, mulch, and fuel continued to impede mulching under CA systems.

This paper from Romania assesses changes in soil properties from a long-term field experiment established in 2009 with various tillage practices and then adapted in 2019-2022 for addition of residues. Results showed that compared to CT, conservation tillage (CA) with partial straw retention (MT) and NT with straw mulching increased SOC, total N, and available K in the 0-30cm soil depth. MT and NT only increased total P and K in the 0-10cm soil depth. The paper also looked at micro nutrients (Zn, Cu, Fe, Mn) but found little differences between tillage and residue systems. But they concluded that CA might be best for maintaining soil quality and high yields.

This paper from Hungary assessed the status of soil in an 18-year-old tillage experiment. looking at physical, chemical and biological properties in 3 tillage systems; No-till (NT), Shallow till (SC), and Ploughing (P). Their results show differences in bulk density (NT>SC) in 0-10cm depth, (NT>P in depths from 10-40 cm. NT had highest SOC in 0-10cm. Soil microbial respiration and abundance and biomass of earthworms was highest in NT. The conclude NT would be a good approach for sustainable soil tillage.

This paper evaluated the effect of CA management - no-till rice straw mulching on soil health parameters including SOC in the inter-rows of two citrus orchards in Spain. Various soil physical, chemical, and biological  were studied in the top soil layer (0-20cm) over 3 years. Their results showed that rice straw mulch resulted in reduced soil temperature that then resulted in higher crop root growth and increased soil macrofauna development and higher soil enzyme activities. The rice mulch also increased soil macroporosity and SOC levels showing that it enhances soil health in citrus orchards in Spain. However, compacted soils, the beneficial effects of straw mulching on soil health were still limited after three years of treatment.

This article from China looks at the long-term affect of tillage and nitrogen addition on yield and soil quality in rainfed maize. Their results show NT plus increased N resulted in higher yield especially in wet years. Over the 18 year period yield enhancement attributed to nitrogen varied from 8.2 to 24.5% with the highest yield under NT. They also found improvements in organic carbon, N availability and P was higher in NT treatments.