Conservation Agriculture Research Updates - April 2026

This paper evaluates GHG emission, global warming potential (GWP), GHG intensity and net SOC variations in rice-mustard-rice cropping systems under CT and strip tillage (ST) on-station. The ST reduced methane (CH4) CH4 flux, GHG intensity and GWP than CT in rice. In mustard ST reduced GHG intensity and GWP compared to CT. There was about 33% increase in N2O emission and 24% augmentation of soil respiratory CO2 with ST compared to CT. There was a 10%  rice equivalent yield increase in ST compared to CT. They conclude that ST can minimize soil C loss, improve net ecosystem CO2 absorption, and reduce GHG intensity and GWP under the rice-mustard-rice system.

This 5-year experiment looked at the best crop establishment-cum-residue management (CERM) practices and suitable crops after rice harvest in rice-fallow systems in Eastern India. Treatments had plus or minus residue Yields of rice were higher (19-32%) in transplanted puddled rice with residue (TPR-R+) over conventional-till direct seeded rice (CTDSR) and zero-till DSR (ZTDSR) treatments. However, TPR adversely impacted the performance of all the post-rainy pulses/oilseed crops. Post-rainy season crop yields under ZTDSR/CTDSR were 15-46% higher leading to higher system productivity as compared to TPR. ZTDSR with residue retention showed higher soil aggregation. The practice of ZTDSR increased the soil dehydrogenase activity, urease activity, soil microbial biomass carbon, and fluorescein diacetate activity in the crop root zone with higher earthworm population and earthworm biomass. More earthworms were found in the rice-pulse system compared to the rice-oilseed system. ZTDSR also had the highest SOC stock. 

This paper looks at the rice-wheat system of South Asia (13.5 mha) but within the IGP where there are 10.3 mha. This intensive cropping system that is vital for food security in India has several environmental issues including depleted SOC, declining water tables, decreased soil fertility and reduced factor productivity. The paper describes various resource conserving technologies (RCT's) such as direct seeded rice (DSR), system of rice intensification (SRI), aerobic rice, brown manuring, crop residue incorporation, furrow irrigated raised bed system (FIRBS), zero tillage (ZT) and leaf colour chart (LCC) that not only improved the production and productivity but also maintained soil health. New emerging technologies like system of wheat intensification (SWI), LCC application for nitrogen management, bed transplanting in rice followed by laser levelling in wheat with zero tillage wheat, incorporation of rice residues over conventional transplanting also showed promising results.

This is chapter 9 of a new book looking at different sustainable sustainable agricultural systems. This chapter looks at CA as a possible way to increase productivity while protecting the environment in India and the Rice-Wheat areas of the IndoGangetic Plains. The chapter explains that CA has multiple agronomic, economic, and environmental benefits. However, in this region adoption of CA has many constraints and challenges including availability of skilled labor, burning of crop residue, alternate use of crop residue for feed and fuel, time taking process, and less information about conservation practices. The authors suggest the various stakeholders work together to promote CA in South Asia.

This 4-year study looked at the effect of different tillage practices and cropping systems on total organic carbon fractions and water stable aggregates in the EGP of India. there were 3 rice cropping systems, and three tillage practices -- CT, RT and RT with 30% residue retention RTR30. The Rice-lentil, RTR30 had the highest carbon stock, TOC, organic fractions and aggregated associated organic carbon. However, RT treatments had increased macro-aggregate size and its associated carbon suggesting a high potential for carbon sequestration reducing carbon loss by reducing tillage.

The hypothesis for this paper was that rotating rice with maize  using CA (strip-tilled maize followed by unpuddled transplanted rice), or seasonally alternating tillage (SAT; strip-tilled maize followed by fully-tilled, puddled rice with residues retained across rotations) would reduce costs and energy use, increase energy-use efficiency, and reduce yield-scaled CO2-eq emissions (YSE) and total global warming potential (GWP), compared to farmers’ own practices (FP) and conventional full-tillage (CT) under the same rotation in Bangladesh’s coastal region. Data suggested that both CA and SAT can result in a range of positive agronomic, economic, and environmental outcomes compared to FP or CT. But farmers had an aversion to use of all CA practices due to problems hiring labor to transplant unpuddled rice.

This paper used a meta-analysis to evaluate crop productivity (wheat, rice, maize) and GHGs for 3 major soil conservation practices: no-till, manures, and biochar. None of the manures were able to reduce GHGs emissions. Use of biochar showed a strong coupling effect between reduction of GHGs  and the increase in crop productivity. Depending on crop type, all cereal crops showed varied degrees of GHGs mitigation under biochar application, with wheat responding most strongly due to the additional yield increment. No-tillage showed a significant reduction in CH4 and N2O emissions under rainfed and irrigated conditions. 

This paper was selected since it was from Pakistan, that researched and adopted no-till in the 1980's but few papers are published from here. The paper collected data from 450 farm households in 24 villages in Pakistan Punjab. Three cropping patterns were found; rice-wheat, maize-wheat and cotton-wheat under an irrigation canal system. It compared Climate Smart (CSA) practices against conventional ones and also estimated the impact of water-smart practices of the CSA, technical training, and groundwater quality on agricultural production. Adopters of CSA practices had higher economic benefits, and improved resource efficiencies compared to conventional ones. They conclude that farmers can earn more profit, save inputs (such as water), and increase their production by adopting water-smart practices of CSA. These should be promoted by the Government and relevant institutions.

This study looks at tillage intensity, crop residue management and green manure (GM Sesbania) on SOC within micro- and macro-aggregates after 6 years of growing rice-wheat in India. The plot treatments included ZT and CT with and without different % of residues and with and without GM. The ZT with 100% rice residue  (ZTWR100) significantly increased soil moisture retention compared to CT w/o residue (CTWR0) and also increased the dehydrogenase (DHA), cellulase, and β-glucosidase activities and the easily extractable glomalin (EEG)- and total glomalin (TG)-related soil protein compared with the CTWR0 treatment. Crop residue retention plus GM significantly improved the proportion of total water-stable aggregates (WSA), mean weight diameter (MWD), and aggregate ratio (AR), compared with the treatments involving residue removal and no GM. 

This paper addresses issues of transplanted rice, by incorporating conservation agriculture (CA) based crop establishment practices in combination with suitable weed management options to sustain rice productivity. Their experiment had four planting techniques; farmer’s practice (Conventional Transplanting), zero-till direct seeded rice (ZT-DSR), reduced-till direct seeded rice (RT-DSR) (Rotavator single pass) and conventional-till direct seeded rice (CT-DSR) plus five weed management practices using various herbicides, plus hand weeding 20 and 40 DAS and a weedy check. Among various crop establishment methods CT-DSR recorded significantly higher N, P and K uptake by both grain and straw over the rest of the treatments except ZT-DSR during both the years. Based on the results application of pendimethalin pre-emergent followed by chlorimuron + metsulfuron at 20 DAS to the CT-DSR treatment gave the maximum N, P and K uptake by both grain and straw of rice.

This study looks at CA in the rice-wheat system of the IGP of India as having the potential to curb negative environmental and health issues in this important cropping system. They also say that adoption of CA is still only modest in this geographic area. The study focuses on the constraints to adopting zero-tillage in RW. Econometric models and machine learning algorithms were used to analyze remote sensing data and farm household data collected from two contrasting locations in the west and east of the IGP. They showed that while farmer adoption was low among smallholders (owning <2 ha of land), the on-farm effects of ZT on variable cost reduction and yield and profit enhancement for smallholders were comparable to larger farms. 

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 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 study assessed the biophysical and biogeochemical impacts and the potential contribution of cover crop practices to sustainable land use using a global dynamic vegetation model LPJmL (Lund-Potsdam-Jena managed Land) V. 5.0-tillage-cc to simulate responses of agroecosystem components to cover crop cultivation in comparison to bare-soil fallowing practices on global cropland for a period of 50 years. They found that cover crops with tillage reduced annual nitrogen leaching rates from cropland soils but also the productivity of the following main crop for the 2 analyzed decades. The largest reductions in productivity were found for rice and modestly lowered ones for maize and wheat, whereas the soybean yield revealed an almost homogenously positive response to cover crop practices replacing bare-soil fallow periods. Their results suggest that having no tillage is a suitable complementary practice to cover crops, enhancing soil carbon sequestration and the reduction in nitrogen leaching, while reducing potential trade-offs with the main-crop productivity due to their impacts on soil nitrogen and water dynamics. 

This paper from Bangladesh looked at intensively grown (3 crops per year) rice-based cropping systems and various management options. This 9-year study examined various 2 soil disturbance - strip tillage (ST) and conventional tillage (CT); two residue retention levels –15% residue by height (low residue, LR) and 30% residue (high residue, HR) and five N rates (60%, 80%, 100%, 120%, and 140% of the recommended N for a rice-wheat-mungbean system. Rice yields were comparable between the two tillage systems for up to year-6, wheat for up to year-3 but mungbean yield markedly increased in ST from year-1. Introduction of ST increased land equivalent ratio by 26% relative to CT, N use efficiency and partial factor productivity. They conclude that by practicing CA with increased residue retention under strip tillage, the crops had higher N use efficiency, grain yield, land equivalent ratio and annual gross margin in the rice-wheat-mungbean cropping system.

This is an interesting paper from Bangladesh on their rice-wheat systems and the benefits that could be obtained by adopting CA based on recent research on-farm over two year on this topic. The conventional system (CS) was plowing followed by three manual weedings without residue from the previous crop. This was compared with CA where  Pre-plant herbicide + single tillage + pre-emergence herbicide + post-emergence herbicide; under rice–wheat and rice–wheat–mungbean systems. The CA was the more cost effective establishment system compared to CS one. Productivity increased in all three crops and by 43% when mungbean was included in the system. 

This is an interesting paper looking at different residue cutting disc coulters for no-tillage in black cotton soils in India. They used different forward speeds of residues of rice, maize and wheat. They collected data on penetration depth, top width, soil disturbance and residue cutting. The least soil disturbance was observed for star wheel disc coulter under maize residue followed by notched, curved teeth, plain and cutter bar blade disc coulter. The change in forward speed did not produce significant effect on residue cutting.

This paper was selected because few papers look at wheat date of planting yet no-till wheat in South Asia came about because it enabled earlier planting and better yields. This paper used a large number of on-farm surveys in the rice-wheat system of the IGP to show that wheat sowing date has in fact a central role on higher yields superseding all other management, soil and varietal factors. They estimate that that wheat yield potential will increase by 69% by adjusting earlier planting dates without affecting rice yield, irrigation requirements or profitability. What I didn't see in the abstract was the best way to plant wheat earlier is to adopt no-till wheat!!

This study was conducted at an experimental farm of ICAR-CSSRI, Karnal on crop diversification and sustainable intensification options using agro-ecological approaches such as Conservation Agriculture (CA) and diversified cropping systems to ensure food and nutritional security while sustaining natural resources. CA-based system management using diversified crop rotations; increased the system yield, net return, protein yield, while using less irrigation water compared to conventional tillage (CT) rice–wheat system. Maize-mustard-mungbean on permanent beds (PBs) recorded the highest productivity, profitability, and saved 82% irrigation water.  In western IGP, maize-wheat-mungbean on PBs was found most productive, profitable and nutritionally rich and efficient system compared to other systems.

This paper reports on a field experiment in the middle IndoGangetic Plains of India to determine if CA can arrest soil fertility decline and improve production in this area. They tested 4 common farming practices that had different tillage, seeding, residue management, and crops. After 7 years, 3 systems lowered Bulk Density and compaction, and higher soil macro-aggregates compared to the conventional check.Avoiding tillage in wheat and including a food legume in rotation increased annual rice equivalent yields by 30.5-34.4%. NT and retention of crop residues had potential to improve soil health and monetary gains.

This is an interesting article from China on the use of smartphones to promote CA. They developed an integrated model to explain the scientific question of how smartphone use influences farmers' adoption of CA — a rice-green manure rotation system (RGRS). The sampled 934 respondents. They showed that smartphones directly contribute to farmer adoption of CA practices. They conclude that knowledge related to environmental degradation and environmental services of RGRS can be imported into smartphone Apps commonly used by farmers to increase information exposure, raise environmental awareness and regulate farmer behavior. 

This farmer field trial in West Bengal, India looked at short-term impact of contrasting tillage (ZT and CT) and cropping systems (rice–wheat and rice–maize) on total organic carbon (TOC) and its fractions, after 4-years of conservation agriculture (CA) in old and recent alluvial soils. Soils samples were taken from 3 soil depths. Results showed that TOC and fractions under rice–maize (RM) cropping system were significantly greater (15–35%) than for rice–wheat (RW) as a result of higher residue biomass addition. Zero-tillage (ZT) improved the C fractions by 10–20% over conventional tillage (CT) in all aspects. TOC and its fractions were observed to be greater under the ZT system in the topmost soil depths (0–5 and 5–10 cm), but the same system failed to improve these at 10–20 cm. They conclude that  ZT under the RM system increases the turnover rates of C in both soil types but the amount of clay influences the stabilization/storage of C.

This study looks at the impact of long-term CA production systems under rice-based cropping systems on pest status. In this study, direct and indirect effects of tillage (zero, reduced and conventional tillage), residue retention and cropping sequences on abundance and damage by pests were investigated. After 4–5 years of experimentation, populations of oriental armyworm in wheat, mealybug and bandicoot rat in rice were found to increase abnormally in CA-based production systems. Conventionally tilled plots had a significant negative effect while residue load in zero-tilled plots had a significant positive effect on larval population build-up of armyworm. Based on the present study, pest management strategies in CA need to be revisited with respect to tillage, residue retention on soil surface, grassy weeds in the field and cropping sequences to deliver the full benefits of CA in MIGP to achieve the sustainable development goals under the climate change scenarios.

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 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