Conservation Agriculture Research Updates - April 2026

This paper looks at the impact of CA on durum wheat in Tunisia as a possible way to mitigate climate change. They looked at yield and water use efficiency. They assessed this over 12 years looking at conventional (CT), minimal (MT) and no-till (NT). Note that their weather data shows a significant decrease in precipitation and increase rain-free days over these 12 years. Results showed that NT had the smallest decrease in yield and the smallest coefficient of variation and thus greater stability. They concluded that the benefits of CA are particularly pronounced in years with extreme drought events, highlighting the importance of adopting such agricultural innovations to mitigate the impacts of climate change.

This is an interesting article that looks at adding no-till potatoes after rice in the Sundarbans of West Bengal, India. The no-till potatoes is diagrammed in this paper and consists of applying a 10cm layer of compost on the soil surface, planting the potato tubers on this compost and then covering the tubers with 20 cm of paddy straw as a mulch. This area after rice is normally left fallow. This experiment was conducted over 8 years to intensify cropping systems and improve farmer incomes. The first 2 years was used to identify suitable potato germplasm. This cropping expansion improved soil health, conserved moisture and reduced labor and costs. The analysis of the estimated adoption also showed that more than 90% adoption is likely to be achieved within a decade.

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 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.

In this study, a 20-year experiment was used to investigate the long-term effects of no-tillage in CA on soil organic carbon (SOC) and nitrogen (N) mineralization, plant N uptake, grain yields, and the grain quality of durum wheat. NT was compared with CT in a wheat/legume crop rotation. After 20 years the CA plot  had 43% more absolute potentially mineralizable N (N0) in the topsoil than the CT plots, with no significant differences observed in deeper soil layers (15–30 cm and 30–45 cm). Other comparisons are made in this paper for different wheat parts. Their results highlight the benefits of long-term CA adoption to increase soil N mineralization, providing a substantial base for N uptake during the critical growth stages of durum wheat, thus leading to increased crop yield. 

This article from Mexico evaluates rainfed, monocrop maize CA cropping systems in semi-arid areas from 2 field experiments on 17 farmer fields planted from 2013-2020. The measured yield and profitability. Maize under conventional tillage was compared to maize on permanent beds with soil mulch, either monocropped or in rotation with triticale, oats, or common beans. Results varied between the two experimental sites. In one site bed planted maize was higher than conventional (CT), while in the other field yields did not significantly differ. In the 17 farmer fields bed planting yielded 70% higher maize than under CT. They conclude that "The most profitable system was permanent beds with a maize-bean rotation in field experiments and with maize monocropping in farmers’ fields."

This long term field experiment at 3 sites in India and one in Bangladesh to assess 4 scenarios: S1 - double cereal rotation with conventional practices; S2 - double cereal plus legume rotation with partial CA; S3 - double cereal plus legume rotation with full CA; and S4 - futuristic diversified cereal-legume rotations with full CA. The main objective was to study the dynamics and stabilization of SOC within these scenarios. Average results showed with passive C pools, , TOC, and Walkley-Black C followed S4>S3>S2>S1 in the 3 Indian sites but reversed S4 and S3 in Bangladesh. Stabilization of C as SOC was higher in the 3 CA scenarios compared to S1 and in rice-rice, compared to Rice-wheat. They concluded that "full CA systems with best management practices (S3) and best management practices with crop diversification (S4) are recommended for sustainable crop production in the major double cereal growing regions of South Asia.

CA is being used in this coastal area of the USA to improve soil health, reduce environmental impacts, and improve farmer profits. They commonly use cover crops, strip, minimal, and no tillage. The paper evaluates the changes in soil properties from various CA  practices. They evaluated 4 tillage systems: conventional, strip, minimal, and no-tillage; 3 winter cover crop systems; fallow, winter cash crop, and high biomass CC. They then measured 6 soil properties over 7 years. Altogether, soil carbon showed a more consistent response to conservation management than the other soil properties, which tended to show greater variability based on the time since tillage. They conclude that conservation practices need to be applied for multiple years in order to improve soil properties. 

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 looks at the effect of cropping systems on larger macrofauna. They sampled 21 fields in France that were used for conventional, conservation or organic systems, either long-established (≥ 7 years) or in transition (≤ 3 years). Tillage, pesticide treatment and organic matter input intensity were assessed in each field. Macrofauna density and diversity, earthworm ecological categories, species richness and functional traits were investigated. They report that density and diversity showed few differences in respect to cropping systems with high variation across years and groups. They conclude that more information is needed on actual cropping systems in order to better assess the impacts of cropping systems on biodiversity.

This paper looks at ways to address the negative soil, environmental, and productivity issues of the major rice-wheat systems of the IndoGangetic Plains of South Asia that are grown on 13.5 mha and are crucial to food security. They evaluated 8 years of research that looked at farmer practices compared to 6 based on CA principles. They look at yield, economic returns, soil quality factors including chemical, physical and biological components and GHG emissions. They conclude that "CA practices and diversified crop rotations can address issues like falling crop productivity, reduced economic returns, soil degradation, and increasing environmental impacts in northwestern India’s traditional rice-wheat system. However, widespread adoption requires government policies, including C credit payments and guaranteed markets with supportive pricing."

This paper from India evaluated CA including residue retention for wheat production to overcome the issues of lower yields, unsustainable practices, and high energy demands of rice-wheat systems on CA fields that that had been maintained for 21 years. The 5 tillage treatments were NT plus (R+) and minus residue (R-), permanent bed planting PBP without residue (-R), rotary tillage (RT) without residue and conventional tillage CT, -R. The CT treatment required higher energy inputs than the other 4 treatments. The lowest grain energy output was RT-R and CT-R. CT-R also had the highest GHG emissions. They conclude that NT+R was the most promising treatment with better sustainability, lower global warming potential and high energy efficiency.

This paper from Brazil looks at SOC storage, crop yield, and soil resilience from a long-term (26 year) experiment in Paraná State that was established in 1989. This LT experiment looks at a gradient of soil disturbance combined with contrasting fertilizer regimes. 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. The paper concludes that combining CA principles ultimately defined the potential for SOC sequestration.

This paper studies the effects of no-till (NT) and residue over the long- and short-term (24 and 3 years) in a semi-arid area of Mexico in a maize-oat-triticale system established in 1995. There were 6 treatments: plow+harrow (PH), harrow (H), multi-plow (MP), No-till (NT), NT with 33% residue, and NT with 66% residue. Soil quality was increased with NT + R by increasing SOM but also total carbon and enhanced microbial abundance. Tillage treatments, however led to lower SOM and lower yields. Differences were also visible soon after the experiment was initiated.

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.

 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.

This article is concerned with the impact of climate change (CC) will have on the productivity of the rice-wheat system in the Indo-Gangetic Plains of South Asia and India that is the breadbasket of these countries. This long term research looks at the potential of long term conservation agriculture (CA) management to address this CC issue. The paper describes 6 different production scenarios with one the traditional system and 5 others that have various improvements on the traditional system including just NT wheat, both NT rice and wheat, addition of a mung bean legume, NT maize and wheat, and one with sub-surface drip for irrigation (SSDI). They conclude that overall, soil organic carbon was higher in all CA scenarios compared to the traditional scenario. "By substantially enhancing soil health and crop productivity, as well as boosting resilience, CA emerges as a promising solution for meeting the increasing food demand in Northwest India and beyond and cropping seasons between and across regions."

This paper from South Africa looks at the production performance, soil greenhouse gas emissions, and soil carbon sequestration of different crop rotations. They measured nitrous oxide and methane fluxes over one year and analyzed 20 years of historical data on soil carbon sequestration, yields, fertilizer use, and wheat protein content. Results showed that rotations that contained legumes and livestock produced more wheat and canola yields and higher wheat protein. All systems showed an increase in SOC over the 20 year period. They concluded that "Legumes and livestock incorporation in crop rotations interact with nitrogen management. Most N2O emissions occurred after precipitation in the otherwise dry summer, making reduction difficult as minimal management activities occur over this fallow period.

This paper from India evaluated a 12-year old CA based pigeon pea-wheat cropping pattern on permanent broad beds with residue (CA-PBB), permanent flat bed with residue (CA-PNB) and conventional (CT). The results showed that the 2 CA treatments enhanced total SOC compared to CT. The CA flat bed showing the highest SOC at 0-5cm and 5-15cm depths. They conclude that residue input increases cumulative mineralization and SOC decay rate vis-à-vis helps to sequester carbon in the recalcitrant fraction, leading to higher stable carbon in soil.

This paper from Germany looks at crop rotation and cover crops on SOC and N content on yields. This 10 year dataset  from 6 locations in Germany was used to calibrate the DSSAT model. They then used a 4-year crop rotation with and without legume cover crops at the research sites with a no CC as a check. Results showed that business as usual (BAU) and no CC treatments had lower (SON) and SOC than with CC's included in the rotation. Legume CC's also did better than non-legume CC's although the latter had less N leaching. winter wheat and oilseed rape crops yields were better with cover crop rotations. Crop rotation with CCs significantly increased water productivity of cereal crops, but did not produce higher yield of winter and spring barley or silage maize compared with BAU unless only legume CCs were used in certain areas that are vulnerable to N losses. 

This study looks at the impacts of no-till individually and with other CA practices on nitrous oxide (N20) emissions and yields using a review of 1270 observations from 86 peer-reviewed articles. Results sho that yields increased by 9.1% while reducing N20 emissions by 6.8% compared to conventional tillage (CT). The results also showed that reduction of N20 emissions and yields were even greater when using other CA practices like residue retention and rotations; reductions in N20 of 15% and increase in yields of more than 30%. The mitigation of N20 emissions was higher in dry versus humid climates. They conclude that "Smallholder farms in Central Asia, South Asia, and sub-Saharan Africa appear particularly suitable for the adoption of conservation agriculture, whereas, in humid climates, high nitrogen (N) input management and silt-clay loam soil should be applied with caution. 

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 article reviews looks at conventional tillage (CT) and no-tillage (NT) systems on wheat yield since this has a direct effect on farmer adoption. They used a collected international database that showed NT is adaptable at all locations. Crop rotation was also important as was residue retention. The data was collected over the past 40 years and demonstrates the importance of NT in increasing the yield of wheat.