Conservation Agriculture Research Updates - March 2026

This paper from Eastern India looks at various ways of establishment of crops in a rice-pulse system and their effect on cellulolytic bacteria. . It has 7 different establishment systems that include the traditional puddling and transplanting for rice but also direct seeding with inter-cropped Sesbania, wet direct sowing, ZT direct sowing and use of drum seeder plus biochar. Their findings show that long-term ZT in the rice-pulse system could be a unique source for efficient cellulose decomposing bacteria and further the efficient bacterial strains isolated from this system can be used as efficient bioinoculants for in situ as well as ex-situ decomposition of rice straw particularly in conservation agriculture

This paper uses a long-term continuous maize experiment to understand water and nitrate-N functions under no-tillage with mulching in dryland farming in China. It reports data for a complete year for spring maize plus the fallow period after 15 years of continuous maize. Treatments included conventional tillage (CT), no-tillage (NT), no-tillage with biochar (NB), no-tillage with straw mulching (NS), no-tillage with plastic film mulching (NP), and no-tillage with straw-plastic film mulching (NSP). Average soil profile water content (SWC) and the soil water storage (SWS) of the mulching treatments  were higher than the non-mulching at each stage. The study did show that mulching is required with NT and just NT may have lower yields. The plastic mulch was the best treatments in their research.

This study examined the impact of different tillage systems on soil organic matter dynamics in wheat based systems on an Inceptisol soil in India over nine years. It compared NT with CT with 4 residue practices none, wheat, soybean and wheat + soybean residue. The results indicated that SOC content increased by ∼48, 42 and 36%, respectively, in WR + SR, SR and WR plots compared with the NR plots in the 0-5 cm soil layer. The SOC content within macroaggregates were ∼30 and 25% higher in the ZT plots than CT in the 0-5 and 5-15 cm soil depths, respectively. The results suggest that ZT management could be adopted for C stabilization within aggregates.

This study identified a site under a long-term NT production system where a known compaction force of 0 Mg axle load (control, C-0), two (C-2) and four (C-4) passages of 2.5 Mg water wagon axle load was applied to cover the entire plot for 20 consecutive years to assess changes in soil hydraulic properties at a site in the Central Ohio, USA. The field was under NT-based corn–soybean rotation since 1997. A wooded lot was chosen as a baseline for comparison. They concluded that further monitoring of the impacts of compaction on soil hydraulic properties particularly on some other properties (e.g., water infiltration and air permeability) across the years is needed.

This study explored the effects of CA on earthworms in a semi-arid climate of the eastern Cape, South Africa. It looked at the effects of tillage, residue and rotations on earthworm abundance. Earthworm species diversity and density were highest under no-till than under CT. Residue retention improved earthworm density regardless of tillage management. Rotations that had fallow periods recorded lower earthworm numbers as compared to continuous cropping systems where wheat was grown in winter. The study concluded that maize;wheat;soybean (MWS) rotation with residue retention results in the highest earthworm abundance and species richness.

Chapter 17 in a 2021 book, "Improving Cereal Productivity Through Climate Smart Practices". An article looking at laser land leveling combined with CA to produce more crop per drop of water. But the chapter also looks at other factors besides NT that are required and obtained by adopting CA. It concludes that to achieve the higher productivity and profitability, adoption of a multipronged strategy of using improved varieties, balanced fertilization, appropriate irrigation, and weed management practices are a must.

This study compared three types of fallow management (ploughing (CT), reduced tillage (RT), and no-till with glyphosate (NT)) on four fields after 17 years of no-plough, which ended with 7 years of CA. Weed density and species richness before weeding was greatest in RT, intermediate in CT and lowest in NT. They conclude that potential benefits of occasional ploughing will depend on the density and composition of the newly upwelled weed seedbank, which will need to be assessed before implementing tillage. From a multicriteria perspective, the long-term benefits associated with CA could largely exceed short-term yield increases associated with occasional tillage. 

This 5-year study looked at rice-wheat in NW India. The goal was to identify management options for further improving productivity and profitability and reducing environmental externalities by drawing on the principles of diversification, precision management, and conservation agriculture. There were four systems. 1. Business as usual transplanted rice followed by tilled wheat; 2. TP rice fb ZT wheat and ZT mungbean; 3. ZT for all 3 crops including ZTDS rice; ZT for a maize-wheat-mungbean system. Results showed that compared to business as usual, the other 3 systems were more productive. These latter 3 systems were more productive and profitable while using less water, energy, labor and lower global warming potential. They conclude these SI entry points need to be placed in the context of the major drivers of change in the region, including market conditions, risks, and declining labor availability, and matching with the needs and interests of different types of farmers.

Mixed groups of scientists including soil scientists, agronomists, agricultural economists and other environmental scientists, facilitated by experienced senior researchers, were presented with multiple subsets each of three states, and asked to rank the states in each subset with respect to expected yield improvement under CA in South Africa. The results revealed two contrasting groups of conceptual assumptions. One group broadly expected larger absolute yield improvements from conservation agriculture in settings where water is most likely to be limiting and the carbon status of the soil is poor. By contrast, the other group expected larger improvements where water was less likely to be limiting. Modelling the ranking process, could be of more general interest for the elicitation of expert opinion about complex soil, crop and environmental systems.

This study compared SOC and SON mineralization rates in the long-term experiment of La Cage (France) under conventional (CON), low input (LI), conservation agriculture (CA) or organic (ORG) management. Disturbed soil samples from the 0−27 cm soil layer of all treatments were laboratory incubated for four months, while undisturbed CON and CA soil cores were incubated to account for tillage effects. They conclude that the increased SOC stocks observed in CA and ORG treatments suggest that increased biomass returns to soil or changes in microbial physiology may be the main drivers of SOC storage.

This study explores the social inclusiveness of zero-tillage (ZT) wheat adoption in Bihar, India. ZT is a proven technology for enhancing wheat productivity while boosting profitability and reducing greenhouse gas emissions in the densely populated Indo-Gangetic Plains. With an average landholding size of 0.39 ha, most farmers in Bihar depend on custom-hiring services to access the technology. They use a panel dataset from 961 wheat-growing households that spans a six-year period to analyze ZT adoption dynamics over time while accounting for the role of social networks and access to service provision. They find that as awareness of the technology increased the service economy expanded. Land fragmentation replaced total landholding size as a significant adoption determinant, which also affected the quality of ZT services received. Hence, farmers with small but contiguous landholdings appear to have gained a significant degree of access over time. We conclude that early-stage assessments may be misleading, and that private sector-based service provision can contribute to socially inclusive development outcomes as markets mature.

This study used a long-term continuous cotton experiment in southeastern USA to  analyze yield data from 1986 to 2018 from 32 management systems to identify how management duration controls the synergistic effect of applied mineral N rates (0, 34, 67, and 101 kg ha−1), cover crops (no cover [NC], hairy vetch [HV], crimson clover [CC], and winter wheat [WW]), and tillage practices (no tillage [NT] and conventional tillage [CT]) on cotton yield and yield stability.Their results suggest that after the initial phase, NT delivers the most consistent yield benefits while enhancing yield stability against unfavorable environmental conditions. Long-term integration of legume cover crops (particularly HV) to NT systems was effective in maintaining high yield and increasing yield stability while lowering N rates.

This study aimed to distinguish actual roles of tillage reduction and residue retention in erosion control based on published data from field experiments of China. Their results showed that residue retention caused significant decline of both water and sediment loss, whereas tillage reduction only led to insignificant change of runoff and soil loss. No tillage plus residue retention was also beneficial in terms of erosion control, very likely due to the application of residue retention. Overall, this study highlights the necessity of understanding the influences of tillage reduction, residue retention and the combination of the two managements in order to better evaluate and manage CA with respect to water erosion control.

Official data on the adoption of CA occurred in Brazil in the 2006 and 2017 agricultural census that provided primary data that made possible an analysis of the dynamics of the adoption of NT practice within the development of CA systems in this country. Expansion of the NT practice throughout the country was strongly associated with the expansion of soybean-based cropping systems involving crops such as maize, wheat or cotton. NT practice improved soil moisture conditions and generated additional growing period that permitted the incorporation of soybean crop into CA cropping systems where it was not possible before. The paper concludes that the use of NT as a lone practice is no guarantee for sustainability, and technology transfer and adoption efforts are also required to reinforce the application by farmers of the other two ecological principles of CA; permanent soil mulch cover and crop diversification through rotations and/or associations.

The paper uses empirical assessments of the performance stability of ZT wheat after rice in the Eastern Gangetic Plains of India in farmers fields. It used panel datasets from 961 farm households in two favorable and two less favorable growing seasons looking at yields and production costs. ZT resulted in yield gains in 3 out of the 4 years and better in less favorable years. More important was significant cost savings in all 4 years. They conclude that ZT wheat provides tangible and consistent benefits to farmers and policy makers should strongly support its adoption at scale.

This is a unique paper looking at slugs as a possible issue by comparing populations from CT and CA in Italy. Predators such as ground beetles are an integrated way to control slugs and their numbers are also measured. Slugs were were common in CT than CA with more beetles in the CA, mulched plots. Soil management such as minimum- or no-tillage and the presence of cover crops/mulch are important elements influencing both slug and ground beetle presence, possibly playing a key role in the maintenance of natural enemy populations.

This study uses Collembola numbers as a good indicator of improved soil properties following a change in land management. They looked at these springtail populations in systems with a history of CA and crop-livestock use in South Brazil. The samples were also evaluated for soil chemical, physical and microbiological properties. CA and CLI management varied in the association of different Collembola's -- epigeic in CA and hemiedaphic and edaphic ones in CLI but these differences were related to different soil conditions. They conclude that Collembola community structure and species diversity were modified by the soil management systems and suggest that the Collembola community may indicate changes across land management systems in conservation agriculture.

This study compares CT with NT with stubble burning and stubble retention and N fertilization on soil carbon and fractions and N. After 50 years, the tillage regime, addition of N and stubble management were all important in influencing carbon pools in the 0.1m depth with N and the tillage regime the most important. But stubble management was important with retention increasing total nitrogen content, stabilizing the C fraction, and increasing the microbial biomass. They conclude the importance of stubble retention and N fertilization in conservation agriculture clearly shows improvement in soil health and maintenance of soil C levels.

This study looks at the influence of SOM, soil temperature and moisture, crop stage, weather and residue management on the emissions of C02 in Spain for CA and CT rainfed systems. The study concludes that total C02 emission values of the different plots of the study for soils under the conventional system (tillage) emitted 67% more than soils under the conservation agriculture system during the 2010/11 campaign and 25% for the last campaign where the most appreciable differences are observed.

This paper looks at ways to minimize the negative affects of continuous puddled rice transplanting by looking at alternative ways to establish rice and their effects on soil health, crop productivity, resource saving and global warming mitigation potential. Innovations in machinery especially for smallholder farms have supported the adoption of the new establishment techniques. They conclude that no single rice establishment technology is superior to others in all circumstances, rather a range of effective technologies that can be applied to different agro-climates, demography and farm typologies.

This study used On-Farm adaptive trials to find out the effect of different crop establishment and weed management practices on yield stability and weed dynamics over the years in Haryana, India. Results showed that DSR with residue (DSRR) coupled with two different herbicides resulted in rice grain yield (5.38 t ha-1 and 5.33 t ha-1, respectively) statistically at par with transplanted rice (TPR)with the two herbicides. The study highlights that, under north-western Indo-Gangetic plains, if the weeds are managed properly, DSRR can be adopted without significant yield reduction during initial years and has comparable yields to TPR. DSRR also saves labor and reduces water use and improves soil fertility in the long-term.

This paper explores the effectiveness of high-resolution topography in characterizing no-tillage (NT) versus conventional tillage (T) surface morphology in order to better understand the hydro-geomorphic processes associated with these crop systems in a clay loam soil in Italy. Surfaces in the NT plots were rougher, had more pronounced slopes and curvatures, sediments with a widespread connection to the plot boundaries, had more irregular flow paths, and had a higher water storage potential due to surface concavities. The NT surface morphology significantly reduces surface runoff, sediment transport, and the off-site movement of agricultural chemicals.

This interesting paper used multi-spectral cameras to measure how long-term CA practices relate to vegetation index. They used a long-term rainfed 2-year rotation with durum wheat and maize including two unfertilized soil treatments were repeated in the same plots every year in Italy. The soil management affects the vegetation indexes’ accuracy, which is related to the nitrogen nutrition status. No-tillage management, which is characterized by a higher content of soil organic matter and nitrogen availability into the soil, allows obtaining a higher accuracy than the conventional tillage. So, the users of multispectral cameras for precision agriculture applications must take into account the soil management, organic matter, and nitrogen content.

This meta-analysis looks at the effect of minimum tillage (NT & RT) plus residue retention on SOC stock in the 0-30 cm soil depth and how these effects varied with soil (sampling depth and texture), climate, cropping intensity and treatment duration. They found that regardless of climate, cropping intensity or residue retention, minimum tillage alone increased overall mean SOC stock -- NT by 11% and RT by 6%. Effects were greater in the 0-15 cm depth than deeper. Residue retention enhanced the resistance to SOC turnover and duration was critical for increasing SOC. They conclude that minimum tillage coupled with residue retention in a double-cropping system is the most promising management system for increasing SOC stocks in the 0–30 cm soil in croplands.