Conservation Agriculture Research Updates - April 2026

This report from CIMMYT, Mexico looked at yield and economics of wheat and maize in a 21 year old experiment comparing these two crops on conventional tilled beds to permanent beds with varying residue levels. They also added tied ridges in the furrows to see if they could offset the negative effects of removal or crop residues. Permanent bed planting (PBP+R) plus residue showed better yields compared to the CT beds. PBP plus full residue also yielded better than partial residue but partial residue with tied ridges had equal yields to PBP plus full residue. But treatments with partial residue and tied ridges results in higher net returns because of the value of residue for animal feed, although this is contingent on the market for residues. 

This article from China uses amplicon sequencing to determine how tillage practices impact microbial communities in plots that have strip till maize (ST), and maize plus residue (ST+R), and rotary tillage maize (RT). Compared to RT, ST and ST+R increased the Shannon diversity index of microbial communities. The paper presents more detailed results. The Mantel test showed that soil bacterial communities were significantly correlated with electric conductivity (EC) and available potassium, while soil fungal communities were significantly correlated with EC and soil organic carbon. They conclude that "strip tillage could improve microbial community diversity and microbial regulation of the N and S cycles in black soil, providing a microbiological perspective for conservation agriculture. 

This another report for a long-term experiment (60 years) from the Triplett Van-Doren No-Tillage and Crop Rotation Experiment established in 1962 in Wooster, Ohio, USA that was designed to evaluate the impact of no-tillage and crop rotation on corn and soybean yields. This experiment is conducted on two contrasting soils, one well-drained and one poorly drained. There were 3 tillage practices; moldboard, chisel and no-till with the residue from the previous crop left in the field and 3 rotations; continuous maize, a 2-year maize-Soybean, and a 3 year maize-forage-forage. Crop rotation was the main driver of long-term crop performance, with the most favorable responses observed when forage crops were included in the cropping system at both sites. Note the forage crops contained mixtures with legumes. The paper contains a lot of interesting data. They conclude that " By evaluating long-term trends, we found that no-tillage can be viable even in clay soils under temperate climates when perennial crops are included in the rotation system. Our results demonstrate that longterm crop yields can significantly benefit from the implementation of both practices adopted together in cropping systems."

This paper presents some of the data from  a family farm in Ohio, one of the oldest continuous NT and cover crops adapted farms in Ohio since 1971. The objective of the study was to assess the effects of no-till (NT) management over 0, 6, 20, and 35 years in a rainfed corn-soybean system, incorporating cereal rye as a cover crop, on soil organic C (SOC) sequestration and total N accumulation across different pools. The results show a significant increase under NT compared to conventional for SOC, total N, microbial biomass C, active C, passive C, particulate organic C and N. They conclude that "long-term NT consistently facilitates SOC sequestration and total N accumulation in different pools, with these benefits distributed non-linearly across distinct SOC and total N pools at the 0-15 cm depth and linearly at the 15-30 cm depth in rainfed corn-soybean systems."

This paper starts out by saying that in Sub Saharan Africa (SSA) tillage and burning of residues is mostly used that causes soil erosion. Maize is also the major crop in smallholder diets. They used the APSIM model to simulate the productivity and protein yield of a variety of intercropping systems involving three crops (maize, cowpea and pigeonpea) under full CA practice relative to conventional tillage (CV) with the same intercropping system. The baseline scenario used daily climate data from 1997-2015 in Northern Mozambique. The results are given in the paper but the Authors conclude that "although under the CA system, there were ng declines in grain yields nevertheless, protein yields and overall productivity remained consistently higher under the CA system.

This study examined CA practices in a maize-wheat system in India using a 2-year field study with 15 treatment combinations. Their results showed that No-tillage (NT) with residue retention (+R) and phosphorus dose (34.4 kg P ha⁻¹) produced the highest (8.17 t ha⁻¹) maize equivalent yield, system productivity, and net economic return. NT + R also significantly enhanced soil organic carbon, water-stable aggregates, microbial biomass, and enzymatic activities. In contrast, phosphorus application with microbial inoculants under NT without residue (-R) yielded the highest energy use efficiency. They conclude that "integrating CA-practices and optimal phosphorus management enhances system productivity, profitability, and soil sustainability."

This paper looks at the impact of no-tillage (NT) and conventional tillage (CT) on soil water and physical properties in Romania using undisturbed soil columns from a field experiment that was a continuous cropping system for 8 years with a 4-year rotation (wheat, maize, sunflower and peas). Various soil physical and water measures were taken. The various measurements can be found in the paper abstract. They conclude that the "findings demonstrate that long-term NT improves key soil hydro-physical properties, supporting its integration into sustainable farming systems to balance productivity and environmental stewardship."

This article from NW Vietnam looks at how CA practices (CAPs) can be adopted to overcome the problems associated with conventional agriculture in this region that has resulted in soil degradation because of intensive tillage and intensive use of chemical fertilizers without adding organic matter. They surveyed 400 maize-farming households. Their analysis shows "that the joint adoption of CAPs is facilitated by education of the household heads, total farmland area, farmers’ access to credit, interactions with extension agents, training on CAPs, proximity to cooperatives, participation in farmers' groups, and plot-specific characteristics." Adoption of CAPs leads to better maize yields and net incomes, especially when all aspects of CA are adopted.  

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.

Crop residue is crucial in CA management to improve soil health and increase yields. This paper from India looks at a residue cleaning system (T1) to help overcome the challenges of residues left after combine harvesting and included design, development and field testing. They first tested the equipment in a soil bin before testing in a field trial consisting of a wheat-greengram-maize cropping pattern and comparing with the Happy Seeder (T2) (an earlier equipment used for sowing into crop residue). T1 and T2 had similar yields but T1 required less energy although it slightly higher carbon emissions. They concluded that T1 had lower B/C ratio compared to T2 but increasing the number of rows in the T1 treatment could enhance field capacity, potentially reducing carbon emissions and improving economic returns.

This paper from Bihar, Eastern India, looks at raised bed planting (RBP) for smallholder maize farmers. They evaluated this management system for 4 rabi (winter) seasons and compared with conventional flat planting (FP). They looked at yield, profitability, water use efficiency (WUE), and nutrient use efficiency (NUE). Maize yields were much higher under RBP than FP but also more profitable with higher net returns, better WUE and NUE. Farmers need to be motivated to adopt this system for Rabi maize. 

This paper from Southern India assesses the impact of different tillage and weed management practices on soil nutrient stratification ratio (SR), carbon sequestration rate (CSR), carbon management indices (CMI), carbon retention efficiency (CRE) and monitor the grain yield of maize after three-years in CA with a cotton-maize-Sesbania cropping system. There are 3 tillage practices; CT cotton and maize, no sesbania = farmer practice; CT cotton- NT maize-ZT Sesbania; and NT for cotton, maize, and sesbania. 4 Weed treatments were herbicide, herbicide rotation, integrated weed management, and hand-weeded control. They conclude that NT plus residue retention and herbicide use would be a viable way to imporve soil health and imptove productivity of the cotton-maize-sesbania system.

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 review article looks at the importance of plant residues with no-till and rotation (CA management). The paper mentions that rotations have spread throughout the World, but only one or two of the three principles of CA are. used in practice with no-till and crop residue more efficient at using rainfall and a more resilient agricultural system compared to conventional tillage but also no-tillage without residues. Without residues, yields are reduced. The authors show that "In areas with low rainfall, the yields were highest obtained in farms that combined NT treatments and the use of crop residues, whereas in rainfed areas with conventional (CT) systems, when residues were removed from NT systems, wheat and maize yields were drastically reduced." Also in many small-scale farms, the residue yield is low and has many competing uses. Crop residues are generally burned in the fields or fed to livestock. They conclude that NT+ R is needed for CA to be successful and adding rotation can provide even better results. 

Agriculture in Moldova in Europe is affected by climate change, market issues and costlier input costs. This paper looks at the a comparison of CA and conventional methods in regards to economic efficiency of their main field crops: wheat, barley, maize, rapeseed, and sunflowers. Their results have significant benefits for CA in terms of profits and better use of natural resources. They collected data from 25 suitable farms from 2020-2024 and the results show CA improves profits, reduces fuel use and mechanical operations resulting in lower costs, better yield stability when drought is an issue. They conclude that the adoption of CA by farmers would help farmers address climate risks and improve their efficiency in use of natural resources in this country.

This is an interesting article that looks at straw biochar's impact on soil fertility, GHG emissions, grain yield, carbon footprint (CF) and net ecosystem C budget (NECB) in an arid region in China based on a 2-year field experiment using 3 biochar quantities and comparing against no biochar. Their results showed that biochar significantly reduced soil GHG emissions, but the highest rate increased methane emissions. Biochar lowered the CF and enhanced the NECB, primarily through increased net primary production and improved soil fertility and crop yields. They conclude that "biochar improved crop yields, NECB, and soil carbon storage while reducing GWP, GHGI, and CF."

This research looked at long-term adoption of residue retention on soil-water and temperature for wheat grown under CA in both a field experiment and crop model simulation using the APSIM (Agriculture Production System Simulator) model. Two tillage practices were NT + Residue retention (NT+R) and CT with residue incorporation (CT+R). The results indicated that the model accurately simulated crop phenology, leaf area index, above ground biomass, and grain yield under both tillage treatments. Soil water content, transpiration and drainage were higher in NT+R compared to CT+R. Evaporation and soil temperature were higher in CT+R. The authors were happy with the APSIM model for identifying the effect of tillage and residue on wheat yield components. 

The Intergovernmental Panel on Climate Change projects an increase in temperature and the frequency of high-intensity rainfall events in the future in most parts of the world. NT was suggested by the UN missions Gap Report as a potential measure to mitigate the negative effects of climate change. This paper from Texas using the APEX model studies the effectiveness of NT in improving resilience of agricultural watersheds to extreme climatic conditions in comparison to conventional tillage (CT). Results showed that NT was significantly effective in reducing annual soil evaporation, surface runoff, and soil erosion and also maintaining rainfed corn yields compared to CT. During high rainfall events NT also minimized runoff and sediment erosion. The authors feel NT needs to be promoted in these climatic conditions.

This research from Uganda looks at nitrogen fixation with pigeon peas in a maize dominant cropping pattern to investigate the effect of biochar under CA on nitrogen fixation at three sites located in different agro-ecological zones. CA involved minimum tillage with planting basins established by hand hoeing. There were 4 treatments: (1) conventional tillage with crop rotation (CT), (2) minimum tillage with crop rotation (CA), (3) CA and plus biochar, applied in both first and second year (CA+BC+BC), and (4) CA and biochar, applied once in the first year (CA+BC). Grain yield was significantly increased by biochar application in CA systems compared to conventional practices, in all seasons and sites. They conclude that "Biological N2-fixation was positively influenced by biochar application under CA systems". 

This paper from Rwanda looks at the low yields of maize, a critical staple crop in this country. The study evaluates the agronomic and economic results of CA compared to conventional systems (CT) by interviewing 222 farms in dry areas of Eastern Rwanda. They found that CA farmers incurred higher total production costs, particularly for fertilizers, seeds, weeding, and irrigation, while CT farmers had significantly higher land preparation costs. But CA achieved 40% higher net profit, 20% higher maize yields, and higher P use efficiency compared to CT. They identified irrigation frequency, seed rate, and nitrogen and phosphorus fertilizer application as key determinants of maize yield using CA compared to CT. 

This paper from Ohio State University's Triplett-Van Doren long-term tillage and crop rotation experiment (one of the oldest NT experiments in the World) looked at the temporal dynamics of soil N and C pools in a maize growing season, in a 55 year old tillage and crop rotation experiment. Tillage treatments were no-till (NT) + residue, Chisel-till (CT) + 30% residue and moldboard till (MT) - residue incorporated. There were 3 rotations: continuous maize, maize-soybean (2-year rotation), and maize-forage-forage (3 year rotation). Their results suggest that crop diversification with perennials enhances soil C and N; NT has stronger effects in clay loam than silt-loam soils; and although C and N pools vary seasonally, long-term management effects persist throughout the growing season.

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.

The authors mention that there are 3.5mha of CA in India but little data on the effects of CA on soil nutrient dynamics like N, P, and S. They have a nine year study on these nutrients in a maize-wheat cropping pattern that compares CA with conventional methods. Results show that CA and N addition significantly enhanced various soil chemical properties and microbial biomass compared to CM for N, P and S and concluded that "These findings contribute crucial knowledge for sustainable development by offering valuable perspectives on N, P and S management strategies."

This study from Brazil looked at the effect on conservation tillage in a subtropical area of China in order to evaluate its suitability for maize in such areas. There were 3 tillage treatments; no-tillage (NT), earthworm bio-tillage (EBT), and traditional rotary tillage (RT). Also 3 residue treatments; none (O), straw (S), and composted cow manure (M). Maize yield and soil samples (0–10 cm) were collected after four growing seasons to determine the maize production, soil properties and microbial communities. Both no-tillage and earthworm bio-tillage increased soil pH, organic carbon, nitrogen and phosphorus contents, especially with cow manure additions, and increased the general bacteria and gram-positive bacteria under none input. No-tillage significantly increased microbial biomass carbon, especially with none and straw inputs.

This paper from NW Cambodia compares use of conventional tillage (CT) with CA in maize cultivation looking at soil health, agronomic, and economic differences. The experiment was set up in 2020 comparing CT and CA with one cover crop (CAS) and CA with a mix of three cover crops (CAM). Soil health was assessed using a Biofunctool. Soil health (SH) was positively increased under CA. However, in the 1st year CA. had lower plant density and suggested that there was a need to improve NT sowing methods. This problem resulted in no significant differences in maize yield between the 3 treatments. Gross value added under CA was 12.7% less than CT in 2021, it surpassed CT by 43% in the second year.