Conservation Agriculture Research Updates - April 2026

The Author highlights the accomplishments made in South Asia since the 1960s that has resulted in this region feeding 28% of the world’s population on 5% of the global land area. "This is the most densely populated region globally, with 2.3 billion people in 2023 (more than that of Europe and North America combined) and covering a land area of about 5.2 M km2. The population of SA, increasing at the rate of 1.7% per year, is expected to double by 2050. He concludes that "The balanced use of fertilizers, the adoption of system-based CA (using drip fertigation and complex crop rotations), and C farming are critical to enhancing SA’s NUE and FUE and sustainably increasing agronomic productivity."

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 starts by saying conventional agriculture is labor, energy and water inefficient and so reports of experiments to identify more sustainable, productive and efficient crop production in a maize-wheat-mungbean system started in 2009-10 and assessed in 2018-19 to 2019-20. Treatments included CA-based bed planting methods such as permanent narrow, broad and flat beds with and without retention of crops residues and 75% and 100% of the recommended dose of nitrogen (N) were compared with conventional tillage (CT) treatment. Results show that adopting the CA practice involving a permanent broad bed with residue using 100% N in this maize-wheat-greengram system was more productive and efficient for nutrients, water, and energy.

This paper from Nepal looked at CA practices plus different N rates on soil chemical and physical properties, nutrient uptake, and yields of a rice-mustard-maize cropping system in an on-farm 2-year experiment. NT+Residue was compared with CT without residue using two crop varieties (hybrid vs local) and 4 nitrogen rates. They conclude that CA plus optimal N significantly improved soil health and yields. Hybrids had higher yields than local varieties.

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 India looks at the causes of a plateau in rice-wheat yields in South Asia. They used a 2-year on-farm study to look at wheat productivity in a RW system. They introduced various system optimization practices (SOP) that include legume inclusion, NT wheat, Direct seeded rice, and bed planting. Benefits of SOP's were reduced global warming potential, reduces water use, reduced weed density, higher partial factor productivity, wheat yield and net return increases, lower energy use compared to traditional practices. They conclude that wheat production with SOP's of legume inclusion and zero tillage achieve higher productivity and profitability with less environmental footprint in the Indo-Gangetic Plains and similar agroecological regions.

This two year field study from India looked at various organic weed management practices  for different tillage and residue management strategies on weed dynamics and yields in a rice-maize cropping system. There were 4 main treatments of tillage and residue management and 5 sub-plot weed treatments in a rice-maize cropping system. Total weed density and biomass in rice and maize at 30 days after sowing (DAS) were minimum for Bed planted NT rice and NT maize plus residue. Apart from the weed free treatment, the best weed control was with residue retention treatments. They conclude CA practices (NT + residues) in R-M systems has less weed issues and improves yields. 

This chapter describes some of the negative issues of rice-based systems in South Asia in terms of feeding an expanding population when groundwater and soil resources are degrading, and climate change is negatively impacting productivity. The mention that some recent management systems like conservation and organic agriculture have shown promise to mitigate the above mentioned negative impacts. But they suggest that adoption of regenerative agriculture that has a more holistic (natural resources, climate change, animal crop interactions, social and economic etc.)  approach may be needed in the future.  It sounds very much like the move from cropping systems to farming systems to Ecosystems suggested in the latter part of the 20th century. Just getting CA management components adopted by farmers has been a major challenge and taken a lot of time. Farmers also adopt parts of the package first rather than the more complex whole package.

This paper hypothesizes that NT plus residue retention can improve energy productivity and efficiency while mitigating the carbon and water footprints, and GHG emissions in rice-wheat systems of Indo-Gangetic Plains of South Asia. Using two tillage practices, CT and NT with and without residue (R+, R-) they tested this hypothesis. The results are available in this paper. They conclude that NTR+ does support the hypothesis noted above and is a viable option to offset carbon emissions and water footprint, promotes carbon sequestration, enhances energy productivity and efficiency in the IGP of South Asia

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 paper looks at how CA affects subtropical dryland farming systems in Pakistan. In a field experiment, fallow-wheat (farmers' practice) and the conservation tillage methods minimum tillage (MT), reduced tillage (RT), and zero tillage (ZT) were compared to conventional tillage (CT) in the main plots and the cropping systems sorghum-wheat (S-W) and mungbean-wheat (M-W) to fallow-wheat (F-W) in the sub-plots. They look at SOC, total organic carbon (TOC), microbial biomass carbon (MBC), particulate organic C (POC), and mineral associated organic C (MOC). They show that regardless of cropping system, cumulative CO2 flow was lowest in ZT plots. The CENTURY model confirmed that continuous use of tillage  is a major threat  to soil fertility and production.

This paper looked at 8 integrated crop management (ICM) practices for 6 years in a direct seeded rice-NT wheat rotation. There were 4 treatments with traditional practices and 4 with CA practices; residue retained and not retained treatments; raised bed and flat treatments. The CA-based treatments outperformed the CT practices for yield, soil quality index, and reduced carbon footprints. They conclude that the CA-based ICM practices proved to be environmentally safer and cleaner and can sustain the food and soil security of the extensive rice-wheat rotation under South Asian ecologies.

There are doubts about the sustainability of the rice-wheat cropping system of South Asia. This paper looked at the yield, productivity, and profitability of wheat using CA. The experiment had 6 cropping systems with rice, soybean or maize followed by wheat and an additional summer mung in all systems. 4 of the 6 treatments had raised beds and 3 had the residues removed. In addition there were irrigation treatments and fertilizer additions. The highest wheat yields were in the three treatments that had NT wheat and Mung. The highest irrigation water productivity (IWP), wheat grain macronutrient uptake, net return, and benefit–cost ratio were recorded under full CA, bed planted soybean-wheat-mung using NT. The conclude that this latter system is a potential option to enhance yield attributes, productivity, and profitability, as well as the sustainability of natural resources in the region while decreasing environmental footprints.

This paper from Pakistan reviews using existing literature the impact of CA on SOC, GHG fluxes, soil health and crop yield. The found that CA management significantly increased soil properties including physical (bulk density, water retention, and aggregate stability), chemical (pH, nutrient availability, and C:N ratio) and biological (microbial and enzymatic) activity. They conclude that "These improvements are critical for maintaining soil health and boosting agroecosystem resilience to climate change. The findings underscore CA as an effective strategy for preserving SOC, improving soil quality, reducing agriculture's environmental footprint and enhancing climate change adaptation in agricultural systems."

Nepal agriculture is challenged by environmental degradation, labor shortages, and increasing feminization of farming as a result of male outmigration. CA offers a solution but adoption needs to increase. This paper examines issues related to adoption CA as more women become empowered in agriculture. The surveyed 383 farmers across 3 Districts and found that 73% of respondents were willing to adopt CA because of climate concerns, economic incentives and market access. They believe that CA enhances sustainability, resilience, and income are also more likely to engage, while market dissatisfaction presents a challenge. Getting subsidies is associated with adoption of CA. Barriers for women include household responsibilities, lack of education and training, and limited financial access. They conclude that targeted policies, institutional support, and market-based incentives are essential for increasing adoption by women farmers. 

This paper from India evaluated contrasting tillage and residue management in the rice wheat systems of the Indo-Gangetic Plains to identify sustainable and energy efficient systems. Treatments include various triple cropping patters that include a legume, but also no-till wheat and rice that were compared with conventional  puddled rice and tillage wheat. NT systems had significantly lower operational energy for irrigation (∼40%), sowing (∼26%), and land preparation (100%) compared to a conventional-tillage (CT) system and also resulted in higher system yields, net energy returns, energy ratios, energy productivity and energy intensity. The authors conclude that the conventional system should be replaced with these more efficient and higher yielding NT + legume systems. 

This report used a multilocation and multiyear trials to compare direct seeded (drilled and broadcast) with puddled transplanted (PTR) Aus (spring) rice using three rice varieties and 3 landscape positions (high, high-medium and lowland) in 3 different Districts in Bangladesh. Measurements included yield, profit, energy use efficiency and and productivity, Global warming Potential (GWP), and emissions. They conclude that DSR is more environmentally sound and economically viable and a climate-smart system and more suitable for highland and medium highland landscape positions. The paper did not mention issues of weed control in the abstract. This is probably a major issue when adopting DS rice.

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.

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 explored farmer perspectives on adoption of CA in Nepal using a survey with key informant interviews and onsite observations. The paper highlights the economic, environmental, and social pillars of CA’s sustainability. They mention the importance of economic viability for farmers but also positive factors such as increased agriculture-related income, favorable prices, and sustainable productivity that shape farmers’ perceptions. Farmers view environmental sustainability by prioritizing and enhancing the local and global environment, viewing their farming methods as climate-smart and actively working towards reducing greenhouse gas emissions. They conclude that strategic communication is needed to effectively convey the benefits of CA to rural communities.

This study explores the experiences and perspectives of smallholder farmers from 6 locations in the Eastern Gangetic Plains where promotional activities since 2013 were part of a "Sustainable and Resilient farming system intensification". There were 3 locations in India, two in Bangladesh and one in Nepal. After coding of data from semi-structured interviews with 44 experimenting farmers and 38 interested non-users, ten common themes emerged that explain why farmers stagnate in their adoption process for CA. Seven of the ten themes were non-specific to CASI and would constraint promotion and uptake of any agri-system change. 4 factors are used in this study to address agricultural change for smallholder farmers; targeting, training, targeted incentives, and time. They conclude that there is a need for a stronger focus on enabling environments rather than technological performance evaluations generically, if promotional efforts are to be successful and emerging sustainable intensification technologies are to be adopted by smallholder farmers.

This paper states that the future of the rice-wheat system, a major food security system for South Asia is at stake because of "Traditional practices like conventional tillage (CT) residue burning, and indiscriminate use of groundwater with flood irrigation". As such this paper studies the role of CA, mungbean integration, water, N, and energy use efficiency in the RW system. The results showed that bundling CA with subsurface drip irrigation (SDI) saved substantial water in both rice and wheat compared to traditional farmer practice. Based on the 3-year mean, CA with SDI (mean of Sc5–Sc8) recorded −2.5% rice yield, whereas wheat yield was +25% compared to farmers practice and rice and wheat yield under CA with flood irrigation were increased by +7 and + 11%, compared to their respective CT practices. Mungbean integration added 26% to productivity. They concluded that CA with SDI for precise water and N management proved to be a profitable solution to address the problems of groundwater, residue burning, sustainable intensification, and input (water and energy) use with the potential for replication in large areas.

This paper from Nepal looks at the issue of crop field fragmentation  that farmers use to ensure irrigation and rainwater in rice and wheat growing areas. This requires lots of labor and reduces the area for planting crops. The paper looks at the possible use of laser land leveling (LLL) to overcome these problems. Obviously, smallholder farmers cannot own a laser leveler so the paper looks at using service providers to allow these smallholders to benefit from this technology. They found that farmers were willing to pay for LLL services. The paper goes on to discuss LLL in relation to farmers with higher land acreages and farmers with low irrigation access.

This book chapter notes that wheat is a major food crop of the World and India. It is a major crop in the rice-wheat systems of the IndoGangetic Plains of South Asia. The chapter discusses the breeding of wheat-adapted genotypes for CA since this management system offers solutions for future food security. They suggest that capacity to germinate when seeded deep, better emergence through residue load, longer and stronger coleoptile, stronger root system architecture, early vigor, and multiple disease resistance are important in CA-adapted genotypes. They conclude that modern breeding tools like genomic-assisted breeding will play an important role in developing genotypes better adapted to CA environments. With advanced genomic tools and the availability of large genomic information, it is expected that newer QTLs will be identified and the molecular mechanism controlling CA responsive traits will be explained.

This paper looked at the potential of CA in a Pakistan dryland area to reduce C02 emissions and alter SOC fractions in plots that had been under NT for 4 years. 4 tillage treatments included CT (moldboard), minimum, Chisel 35cm (MT), reduced, Chisel 45cm (RT) and NT. There were 3 cropping patters; sorghum-wheat, mungbean-wheat and fallow-wheat. All the wheat, mung , and sorghum residues were returned to the NT plots. In the other treatments the residues were incorporated into the soil by harrowing after plowing. Results showed that CT plots had lower SOC than NT or RT plots. The F-W and M-W had higher microbial carbon and organic carbon than S-W. Cumulative C02 flow was lowest in NT plots in all cropping patterns and suggest NT and RT are potential systems for carbon sequestration  in dryland soils.