Conservation Agriculture Research Updates - April 2026

This research from NW India analyzed data from a 17-year long term experiment that concentrated on crop establishment, tillage and residue management in a rice-wheat system. This cropping system and region of India is impacted by residue burning and GHG emissions. The experiment had 5 scenarios from the traditional system of puddled transplanted rice followed by tillage before planting wheat with all residues removed (Traditional) to NT direct seeded rice (NTDSR), NT wheat (NTW) and 1/3rd residue retention (RR) of both rice and wheat. Among the scenarios the NTDSR-NTW-RR one achieved the highest carbon management index across both the soil layers, indicating a reduced need for carbon management due to higher TOC  compared to the traditional system. They conclude that "reduced or no tillage combined with residue retention in RWS holds substantial potential for increasing carbon sequestration, reducing net GHG emissions, and lowering carbon footprints. Additionally, this practice offers an alternative to crop residue burning, a significant contributor to air pollution in the western IGP."

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 mentions that maize, wheat and rice account for 90% of the total cereal production globally. They suggest that a new approach to cereal production is needed to overcome food insecurity, climate changes and unsustainable land use. They propose that integrated crop management (ICM) is an avenue to explore. This article reviews 108 studies from literature over the last 23 years.The review the data from Asia, China, USA, and Africa. Their data shows that ICM increased yields in rice, wheat and maize but despite this potential, widespread adoption faces technical, climate-related and economic issues.  They suggest that overcoming these issues requires targeted training, improved extension, and supportive policies.

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 paper looks at the rice-wheat system in Eastern India where smallholder farmers are using excessive water and nitrogen with soil degradation. They used field studies and a crop simulation model to assess resilience, viability, and sustainability of this cropping system under CA with different irrigation methods and nitrogen rates. They had 4 treatments from the puddled transplanted rice (PTR) and zero-tilled wheat (ZTW) with flood irrigation to direct seeded rice (DSR) fb ZTW with sub-surface drip irrigation and 75% and 100% recommended N and a N control plot. The DNDC model accurately predicted soil mineral N. DSR-ZTW with drip irrigation  enhanced sustainability and productivity compared to PTR-ZTW and reduced methane emissions by 70-80%. This system also provided the highest system yield, lowered water losses and improved N use efficiency, and reduced GHG emissions. 

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 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 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 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 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 Japan reviewed 68 papers to look at 13 field management categories in terms of importance for mitigation of climate change.The management categories were evaluated in terms of yield, area-scaled greenhouse gas emissions (GHG), and yield-scaled GHG emissions against base management practices. Yield increases varied from -6 to +12%. Only non-puddling increased yield and reduce both types of GHG emissions. Water management, (alternate wetting and drying or single and multiple drainage and notillage), reduced both GHG emissions, but reduced yield slightly. The paper concludes and recommends nonpuddling, water management and no-till as climate mitigation options, but suggests other categories like soil fertility be included.

This article is a three field study that looks at CA as a cost-effective alternative  to conventional tillage (CT) in rice-wheat systems in Karnal, Haryana, India using a flooded (FL) and sub-surface drip (SDI) irrigation. Results show that in rice, in ZT direct seeded rice with residue (+R) and SDI recorded 73% less weeds than the CT-puddled transplanted rice after 3 years. However, the ZTDSR without residue (R-) with flooding had the highest weed density and weed dry matter 37% less rice yield after 3 years. The paper lists the various weeds present. The same was found in wheat with the lowest WD and WDM in the ZT + SDI in year 3. The CA system improved yields over CTRW systems in weed free (WF) conditions, regardless of residue and irrigation management and should be recommended for RW systems.

Burning of crop residue by farmers so they can easily prepare land for the next crop is common in India that creates a health issue by polluting the air. It also contributes to C02 and black carbon emissions that then affects climate change negatively. This paper points out that the introduction of the Happy Seeder from Australia allows farmers to sow the next crop without removing the previous crop residue and so is an effective alternative to burning. However, the supply of this seeder is limited and this delays planting of wheat after rice that results in lower wheat yields. This paper looks at how this predicament can be resolved in India through Government policies. 

This paper suggests that CA adoption is crucial for enhancing SOC and mitigating climate change for future food security. The research assesses the effectiveness of various factors controlling SOC sequestration derived from literature reviews and 469 data points spanning 42 years.Results showed that CA significantly increased  SOC by almost 30% compared to CT. The highest SOC result was no-till, plus chemical fertilizer (CF), and straw return (S). Interestingly, CF + S or CF + manure led to greater SOC sequestration compared to the application of CF alone. Also, the annual SOC change rate (ASCR) of CA is closely linked to the experimental duration of its application, demonstrating an overall exponential decline followed by stabilization after several years. Overall. this paper contributes to the understanding of how CA sequesters carbon in soil.

This study looked at the components of CA individually and in combinations with a control on soil carbon and nitrogen dynamics for a direct rice seeded-green gram system. Reduced tillage alone and in combination with rotation resulted in 10% and 6% lower CO2-C release than the plots with residue retained. The paper has results on the role of rotation and crop residue on various enzymes. They conclude that rotation and residue retention are effective for better C and N cycling in this system. Tillage on the other hand needs a longer time to show beneficial results than the 4 years of this study. The increase in soil enzyme activities improved microbial activity, which can further enhance nutrient availability for plants. and help improve soil health.

This study from NW India using on-farm research explored how different duration's of CA (2, 4, 8, and 12 years) compared to conventional tillage (CT) on SOC, soil aggregation, and system productivity. Results showed that adopting 8-12 years of CA led significant increases in SOC in the topsoil (5cm) and 5-15cmand improved percentages of macroaggregates. But 8-12 years of CA resulted in20-25% reduction in soil inorganic carbon compared to CT. They conclude that enhancing SOC with long-term CA can improve climate-resilient wheat yields in NW India

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 addresses the issue of managing the large amount of biomass straw after combining rice in India. The easiest and most common farmer way is to burn the straw so land preparation is easier, but this comes with negative environmental problems especially air pollution from the smoke. CA can be a good option since the surface straw can help improve soil health, but low temperatures and nitrogen levels slows decomposition rates, immobilizes nitrogen and hinders land preparation, although CA uses no-tillage. This paper applies fungal inoculants to enhance bacterial degraders. The paper also looks at the genomic insights for choosing appropriate decomposers. The paper talks about incorporation of straw, whereas in CA, the idea is to maintain the straw as a surface mulch and minimize soil disturbance through tillage. Just enough to sow the seed into the mulch with equipment designed to plant efficiently into the residue.

This study is undertaken at the Ifugao Rice Terraces in the Philippines, an Agricultural Heritage system. They surveyed farmers in this region on the socio-demographic, environmental, and economic factors influencing the adoption and persistence of Environmental Conservation Agriculture (ECA). They found the shift to high-yielding rice in ECA led to a decline in the use of Tinawon rice, an important component of this Heritage site. They suggest it is important to balance modern practices with continued use of the traditional system to preserve biodiversity, soil health, and cultural identity. Climate change presents both challenges and opportunities for adaptation, making it essential to integrate traditional knowledge with modern techniques to build resilience. 

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 looks at microbial potential in low input-based CA to improve productivity. They looked at an array of microbial groups; bacteria and fungi, in 3 cropping systems; a rice-maize-cowpea, rice-wheat-mungbean, and rice-cauliflower-winter rice with 3 tillage practices CT, reduced tillage (RT), and NT with different levels of residue and fertilizer. The early stage of CA adoption showed a sharp decline in microbial population compared to the initial population except for the fungal components.The abstract has other results. They conclude that although the transition stage of CA shows a decline in microbial population, long term adoption of CA gradually restored the higher microbial numbers and biomass in soil.

Development of equipment to allow farmers to plant crops using NT and residues is important and so I am presenting this paper from PAU in the Indian Punjab as an example of local development to allow farmers to grow crops after rice without burning the residues. The paper reports on a four-wheel tractor seeder (PSS) that can sow wheat with success in a combine harvested rice crop. They evaluated the PSS seeder under varying straw load, forward speed, rotor speed, fuel consumption, field capacity, seed emergence and grain yield. They compared these factors for the PSS against the Happy Seeder (HS) and Super seeder (SS), two previously developed equipment used for NT wheat into rice residue. They concluded that "the PSS showed promise for in‐situ management of rice straw as it eliminates most of the operational problems encountered by the existing seeders (HS and SS)."