Conservation Agriculture Research Updates - April 2026

This paper is included as it provides data on the progress and acreage of CA globally. The article says CA since 2008/09 has expanded globally at an annual rate of more than 10Mha per year. It has risen to 205.4 Mha in 2018-19 or 14.7% of global cropland area. The spread in Asia, Africa and Europe was suggested as due to better organized farmers and better networking. Expansion is also mainly farmer driven. The paper has several lessons elaborated from the global spread of CA responding to 5 key questions.

This study was conducted to evaluate the effects of maize residue management and tillage (CT vs NT) on soil health using the Soil Management Assessment Framework. After three years, maize yields were 15% greater under NT than CT. They conclude that understanding the importance of crop residue utilization in conjunction with no-till practices in surface irrigated agroecosystems can influence the adoption of sustainable management practices and should directly contribute to long-term soil health improvements and agroecosystem sustainability.

This paper explains some of the benefits of CA adoption in India including a yield advantage, water savings, reduction in costs,  increased net returns, reduction in global warming potential and other climatic benefits.  They estimate that global warming potential of about 25 Mt CO2 eq. i.e., about 15% of the emission from the crop sector (agricultural soil, rice cultivation and crop residue burning) is mitigated by the adoption of various CA practices and other mitigation technologies in India. But adoption is hindered. They conclude that business models need to be developed for creating custom hiring centers, manufacturing hubs and enhanced capacity development of the stakeholders to realize the full benefits from CA.

This paper reports the origins, history and recent advances in CA and report that CA is now practiced on about 200 mha globally. They mention that regenerative agriculture (RA) have no scientific definition but generally adopt CA. This paper suggests that a single definition for agricultural sustainability via a multi-stakeholder world congress would standardize certification and de-confuse the market. RA describes exactly what CA does for soil health and all farmers need to unite around a new “Combined Regenerative Agriculture” (CRA) to lobby for adequate payments for environmental services. The paper also says expansion of CA is critical for world sustainability. Many gaps and constraints exist, especially for smallholders.

This paper looks at the transition from conventional flooded transplanted rice to direct seeded rice in NW India. The main challenge in these light textured soils is weeds. This study looked at the removal of nutrients by weeds under three different rice treatments as main plots (DSR-ZT; DSR-CT; DSR-RT) and three sub-plots under the following wheat (CTW-R; ZTW-R; ZTW+R using a happy seeder). Overall, the research study concluded that weeds on an average remove 25.65 % macronutrients (N, P, K) and 51.47% of micronutrients (Zn, Cu, Fe and Mn) in DSR under rice-wheat cropping system.

This is another paper looking at mechanization and service providers but focused on empowering women farmers. The paper describes the many hurdles and drudgery women face farming their land with out-migration of male members of the household. For example, fewer rights over land make it more difficult for women to access subsidies, finance, or mechanization. The paper describes 3 ways that sustainable mechanization can empower women and respond to their predicament. The paper also provides a catalogue that highlights the potential for smallholder farmers, including women, to earn an income via mechanization hire service. The information for each machine or equipment is also included in this paper. The target audience includes extensionists, gender experts, agricultural engineers, government officials, donors, micro-finance institutions, and implementing partners.

A field experiment and meta-analysis was used by the Chinese study to look at the effects on no-tillage on wet stability of aggregates (WSA), clay dispersibility (ClayDis), mean weight diameter (MWD), and aggregate SOC distribution and mineralization in rice paddies. Four tillage practices: no-tillage, rotary tillage and moldboard plow tillage with rice straw retention (NTS, RTS and CTS respectively), and moldboard plow tillage with rice straw removal (CT). Additionally, the meta-analysis showed that no-tillage increased the macroaggregate content, WSA and MWD. They conclude that In rice paddies, the increased macroaggregate content may contribute to increasing SOC, which improves soil structural stability (SSS) under no-tillage.

This paper looks at and presents findings to better understand the challenges and find solutions to help farmers adopt better, more resilient farming practices. The information is based on participatory discussions with farmers in Michigan. They looked at policy, economic and structural barriers that inhibit adoption of conservation systems. The results were complex with barriers and opportunities, including markets, social networks, human capital, and conservation programs. Making it more difficult are many community constraints, market access and availability problems, climatic and environmental changes, and policies (governmental and corporate) that cross-pressure farmers when it comes to making conservation decisions. Better understanding these constraints will help with the adoption of CA.

This chapter in a new book entitled "Microbiome Under Changing Climate" looks at how microorganisms are affected by climate smart practices. This includes affects on GHG emissions. They provide a systematic selection of novel experimental studies to highlight the impact of climate change consequences such as elevated CO2, temperature, and drought on microbial functions in different agroecosystems. They also describe the role of microbes in CSA strategies that influence yield, carbon sequestration, GHG mitigation and climate change adaptation.

This report from Spain in a semi-arid agro-ecosystem looked at different nutrient sources under minimum tillage. Organic amendments were compared with mineral fertilizes over a 5-year crop rotation using wheat. Wheat yield and biomass, and several soil properties were measured (pH, soil nutrients, soil organic matter  potentially mineralizable nitrogen, total microbial activity and heavy metals) throughout the 10-year study. Wheat yield was better under organic compared to mineral fertilizer. The application of organic amendments under MT resulted in a promising management agro-ecosystem compared to the mineral fertilized because crop nutrients came from organic wastes, no herbicides were applied while the yields were higher.

This study looks at the issue of weed control in CA systems that has labor and costs of production problems. This study looked at a CA based rice (direct seeded)-wheat-mungbean cropping pattern over two years of study. The goals were to study the types and distribution of weeds in non-puddled rice and following strip-tilled wheat fields, and to find the most economic way to manage the weeds in both crops. The latter goal included using herbicides. The most most effective treatments involved two herbicides with one applied pre- and one post emergent in wheat and two other herbicides in direct seeded rice also applied pre- and post-emergent.

This paper starts by saying Green Revolution (GR) agriculture is faltering and needs to be replaced to meet the needs of the Sustainable Development Goals (SDGs). It describes the role of CA in accomplishing this goal. They explain that CA can raise productivity, reduce inputs, regenerate degraded land, reduce erosion, and improve the flow of ecosystem services and so contribute to several SDGs. It highlights that CA is spreading globally at an annual rate of about 10 mHa per year. In 2015-16 it was estimated to cover 180 Mha with 48% in the Global South. It further discusses what is needed for CA to contribute to SDGs to contribute to lasting  quality of human life and nature.

This paper from India looked at the long term effect of various CA practices on infiltration of water using modeling. Treatments included a check (CT), Permanent narrow beds (PNB) and wide beds (PBB) with and without residue (+R) and NT. The initial and cumulative infiltration rates were highest in the PBB+R treatment and lowest in CT. Bed planting with residue was better than BP without residue that was better than NT without residue. After checking the model performance, it was found that simple empirical Kostiakov (1932) infiltration model represented the infiltration rate and time relationship in a better way and characterized the best fit with the experimentally observed field infiltration data.

This study had four scenarios Sc1. farmers practice transplanted rice (TPR) followed by conventional tilled broadcasted wheat (CT- wheat) with residue removal Sc2. TPR followed by zero tillage (ZT) wheat and mung bean with partial residue retention. Sc3. direct seeded rice (DSR) followed by ZT- wheat and mung bean with full residue retention and Sc4.  ZT-maize followed by ZT-wheat and mung bean.They were used to study the humic acid (HA) content and stability of soil carbon with these scenarios. Sc4 recorded significantly higher HA content at 0–15 and 15–30 cm soil depth. They conclude that CA is efficient in enriching organic carbon but also a more stable complex of HA.

This paper suggests that to till or not to till is still a confusing question for many farmers. The objective of this paper is to clearly distinguish between the different principles of CA, and determine the net effects of NT on improving and sustaining agro-ecosystems based on 49 recent meta-analyses. The study concludes that no-tillage by itself leads to yield declines, whereas residue retention is the main driver for yield increases. The same result was found for water erosion control and carbon sequestration with residue retention once again a key driver for improvement. They conclude that to till, or not to till, is not the question: residue retention seems more critical. This supports some other data that no-till by itself is not optimal but with residue retention it becomes beneficial.

This study estimated the the spatial-temporal variations of maize yields from 13-year on-farm trials from 4 countries in Southern Africa. Agronomic data from long-term CA trials is used with gridded biophysical and socioeconomic variables. Comparisons were made between CA and CT practices with above and below average precipitation. The variable importance analysis showed that the altitude, precipitation, temperature, and soil physical and nutrients conditions variables explained most of the variation in maize grain yield. Maps were generated to identify the locations where CA had a yield advantage over CP during seasons with below and above-average precipitation. The paper concludes that multi-source remotely sensed data, coupled with advanced and efficient machine learning algorithms provides accurate, cost-effective, and timely platforms for predicting the optimal locations for upscaling sustainable agricultural technologies. 

This is another paper looking at the shift from CT to CA and the issue of weeds and in this paper the weed seed bank. Two on-farm CA experiments were sampled at two sites in Bangladesh for the effects of strip planting (SP) and bed planting (BP), plus no-tillage (NT) in one site with increased retention of the residue of previous crops (20% vs. 50%). The conventional tillage (CT) and 20% residue was the control treatment. The weed seedbank in 0–15 cm soil was quantified by assessing the emergence of weeds from soils collected from the field after irrigation i rice and after wheat. The fewest number of weed species (especially broadleaf weeds), and the lowest weed density and biomass was in SP, followed by CT, BP, and NT, with 50% crop residue mulch. Relative to CT, the SP, BP, and NT produced relatively more perennials weeds. They conclude that continuous CA, for 3 or more years, in two rice-based crop rotations, decreased the size of the weed seedbank, but increased the relative proliferation of specific perennial weeds. 

This paper looks at biological soil quality in the IGP of India in rice-based cropping looking at tillage and residue management. The objectives of this study were to determine the effect of seasonal variation on enzyme activity and assessing biological soil quality (BSQ) under conservation agriculture (CA)-based rice-mustard cropping. They collected soil samples in the 9th year from two soil depths and looked at biological attributes. They found that the CA-based NT systems with rice-mungbean-mustard with residues had the best biological attributes and recommend this system in India

This study in Bangladesh looked at two rotations; lentil-mung bean-rice and wheat-mung-rice with strip planting or bed planting, along with residue return, on SOC pools after 1.5 years, compared with intensive conventional tillage (CT) and limited residue return. CT had higher CO2 emission compared with strip planting or bed planting as did high residue return. In the legume-dominated rotation, neither practice sequestered SOC. They conclude that strip planting with high levels of crop residue return can be an effective and quick strategy in either slowing the loss of SOC or improving C sequestration.

This paper addresses the serious problem of rainfall erosivity and water erosion in Brazil. In the last 50 years, the Brazilian Cerrado had 53% of its original vegetation converted to agriculture and pastureland. The objective of the present research was to compile, systematize, and statistically analyze the existing erosion plot data in the Brazilian Cerrado, correlating the observed results with different environmental and management factors, and with the corresponding soil loss tolerances. The research results provide useful elements for the development of sound conservation policies in the Cerrado and in other similar savannas of the world.

This 3-year study was undertaken in northern Italy. Bulk density (BD), penetration resistance (PR), soil hydraulic saturated conductivity, and sorptivity were used to evaluate soil quality obtained by combining three tillage intensities (conventional tillage – CT; minimum tillage – MT; no tillage – NT) with three winter soil coverings (bare soil – BS; tillage radish cover crop – TR; winter wheat cover crop – WW). Reduced tillage coupled with WW improved soil physical properties even below the tilled layer, as evidenced by root-growth-limiting condition reductions. They conclude that, despite the increase in BD and PR due to reduced tillage, the strategy improved soil functioning and particularly soil hydraulic conductivity. In the short term, the WW cover crop moderately increased physical soil parameters, whereas TR had negligible effects. This study demonstrates that, to quantify CA, several soil physical parameters should be monitored.

This study from China looked at long-term straw mulching under a no-till system  on soil physicochemical and biological properties at different soil depths (0-30 cm in 10cm increments) in a no-till rice-wheat system. Straw was removed (CK) or mulched (SM) in this 12-year study. Organic carbon, nutrients, and bacterial abundance were reduced by depth, but pH increased. SM significantly increased total N, inorganic N, available P, available potassium, and soil water content at 0-5 cm, total organic C content at 0-10 cm, and dissolved organic C and N contents at 0-20 cm compared to CK. The study also reports data on the effect of SM vs CK on various bacterial groups. Overall, they conclude that the SM treatment is highly recommended under a no-till system because of its benefits to soil fertility and bacterial abundance.

This paper looks at adoption of agricultural technology rather than specifically CA, but their findings are relevant for CA as well. The contend that adoption of many seemingly beneficial technologies remain low. This study looks at various reasons that explain adoption from 367 regression models from published literature. They find that farmer education, household size, land size, access to credit, land tenure, access to extension services, and organization membership positively correlate with the adoption of many agricultural technologies. Improved varieties and chemical inputs are adopted more readily on larger farms, which casts doubt on the scale-neutrality of these technologies. Credit can positively influence adoption, but researchers should measure whether farmers are credit constrained, rather than simply whether or not they have access to credit. They conclude that efforts to promote agricultural technologies in the developing world must be adapted to suit local agricultural and cultural contexts. 

This is an interesting chapter 2 in a book entitled Advances in Organic Farming, that looks at recent findings, advantages, drawbacks, and opportunities for introduction of CA into Organic Farming. Advantages include less erosion and degradation due to improved soil structure, increase in soil carbon stock, diversity of macro- and micro-organisms, and reduction in nutrient loss through run-off and leaching. But since CA and OF have contrasting strategies there are difficulties that need to be overcome. These include weed control, soil compaction, slow mineralization rate, restricted choice of crops, unavailable equipment, low incentives and funding, and links to organic markets. 

This is an interesting article that looks at custom hiring centers (CHC) for mechanization in Nepal and South Asia (India and China). The paper reports that there has been minimal reliable reporting or evidence on the success of their efforts. Yet, there is very good reason to believe that with refined backstopping and informed selection, CHCs can be successfully used to provide mechanization access for underserved geographical areas and their communities. The paper ends with recommendations, observations and considerations for policy and agricultural development professionals and the existing CHC's management committees (MCs) around establishing and/or the improving CHCs and their management.