Conservation Agriculture Research Updates - March 2026

The authors used a mobile, closed chamber system to determine soilborne, greenhouse gas (GHG) emissions from rainfed, farmer-managed CA- and conventional agriculture (CONV), in northern Zimbabwe in on-farm sites that varied in soil fertility and environmental conditions. Field emissions were highest under
warm-moist conditions, which are prevailing for large
parts of the growing season. See the abstract for detailed results. They conclude that "the mitigation effects of CA are highly
site-specific and that CA management practices can have unexpected negative effects on GHG fluxes. The
unimodal rainfall distribution with a long dry winter
period of 7 months and recurrent dry spells in north-
ern Zimbabwe may prevent a net carbon sequestration
under CA management that would have occurred in
the humid tropics.

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 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.

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 paper from Malawi looks at ways to overcome the problem of climate change impacts that have affected food production. They looked at improved varieties on total productivity and nutrition under maize-legume CA systems over 13 years of on-farm experiments in Malawi. the 3 main treatments were 1. CT of sole maize planted on raised beds; 2. NT of sole maize on retained ridges + residue; and 3. CA maize intercropped with either cowpea, pigeon pea or groundnut on retained beds using NT. The results showed that total system nutrition was highest on the 3rd main treatment. The yields of maize were significantly higher in the 2nd and 3rd treatments irrespective of the variety grown. They conclude that "Conservation agriculture and NT systems have more influence on productivity of smallholder farms, despite the genotypes used (hybrids or OPVs)."

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.

Low yields are often related to variable rainfall in semi-arid regions under conventional farming. This paper from the highlands of Mexico evaluates CA in 2 sites on-farm experiments and 17 farmer fields from 2013-2020 to assess yields and profits. Maize grown conventionally on the flat (CT) was compared with maize on permanent beds with residue mulch. The latter plots had monocrop maize and three rotations with either triticale, oats, or common beans. Results showed that average maize yields on beds exceeded CT maize by 70% in one location. Whereas in a second location there was no difference in maize yields between CT and CA systems. On the farmer fields, bed planting was 70% better then the CT. The most profitable rotation was maize-beans in farmer fields and the 2 on-farm trails.

This article reports uses on-farm data from France, Sweden and Romania  compared to field-experiments nearby to look at reduced tillage, organic farming and use of ley-grass periods into crop rotations to evaluate a more sustainable use of soils. No-tillage generally increased the mean SOC and total N contents of arable fields in comparison with ploughing but only in the 0-10cm layer. NT had no general affects on soil biology. In France, organic farming and ley-grass implementation into the crop rotation increased SOC and total N contents to the level of the no-tillage fields. The On-farm research gave similar results to the long-term field experiments. However, they suggest OFR is important and less costly than field experiments and also helps to exchange knowledge between scientists and farmers.

This paper from Lithuania looks at the relationship between root network development and CO2 emission as affected by different cropping and tillage strategies. They tested 5 different cropping systems with or without cover crops (CC) using different tillage practices. Results showed that with no-till (NT) C02 emission was higher than in conventional tillage (CT). Increase in CO2 emission also varied between 30 and 35% depending on the share of legume and CC inclusion. Root growth and development were significantly affected  by soil depth and cropping strategies in terms of root length and root volume changes. The inclusion of CC resulted in a decrease in root volume. Root length and root volume had a significant impact on soil CO2 emissions. They concluded that crop diversification and addition of CC helped reduce C02 emissions and improved root networks better than monocropping.

This article reports the results of evaluation of new wheat cultivars in on-farm conditions using different tillage systems. There were 7 wheat cultivars (3 bread wheat and 4 durum) and 3 tillage systems; conventional (CT), reduced (RT), and No-Till (NT) in two locations for 3 cropping seasons. Overall the CT treatment had the highest yield and NT the lowest. But maybe that was because there was no residue mulch or there were problems with the NT equipment or soil moisture at planting. NT needs a higher soil moisture at seeding that a CT soil. However, there were differences in yield between the different cultivars by tillage. Some cultivars had better yield under CT and others under NT. The experiment needs to look at cultivars by tillage with and without residue and plant the NT when the moisture is higher and not wait for the CT plots to be planted.

This paper starts by saying that although CA facilitates build-up of SOC, the sequestration potential of arable soils is affected by edaphic factors and is not well understood. The research used an on-farm approach with pairwise comparison of 21 conventional vs highly innovative ‘pioneer’ farms across a wide range of arable soil types and evaluated the leverage of site attributes and management practices such as crop diversity, reduced tillage, organic fertilization, cover cropping and inter cropping on the SOC sequestration potential. While most pioneer management practices proved beneficial for the sequestration of SOC – particularly cover cropping and crop diversity – our results clearly show that soil texture was the most significant shaping factor. Coarse-textured soils had a significantly higher potential for SOC accrual compared to medium- and fine-textured soils. The initial SOC content also had a significant effect on prevalent sequestration potentials. They conclude that carbon farming schemes need reconsideration within the state-of-the-art scientific framework of carbon saturation behavior in order to properly account for biophysical constraints when formulating soil-related climate change mitigation policies. 

This paper evaluated CA as practiced by farmers and compared farmer understanding of soil health in three East African countries. CA and non-CA fields were compared by sampling for 2-3 years. CA and non-CA fields were located close, on soils with the same texture, growing similar crops. Most of the CA fields were planted in basins. Farmers and technicians collected the data together. Farmers said that CA improved hoe-ability, crusting, smell and water infiltration. Fields under the CA treatment had a higher probability of rating better than non-CA fields. The paper discusses both benefits and drawbacks of using participatory, on-farm research. They conclude that farmer participation as citizen scientists will advance soil restoration in East Africa and increase the potential for farmer-to-farmer knowledge exchange of soil-improving practices.

This paper considers the short-term effects of wheat-maize and wheat-soybean on fractions of soil organic carbon, P and other soil quality properties in the 0-200mm and 200-400mm soil depths on CA farms. Water-soluble carbon and available phosphorus (P) (NaHCO3 Pi) were significantly higher and NaOH  Pi was lower in maize/wheat than in soybean/wheat sequences. SOC, extractable P, and NaHCO3 Pi were significantly higher in the 0–200 mm than in the 200–400 mm depth. They conclude that short-term cropping sequences do not affect SOC sequestration but a wheat crop preceded by maize could benefit from higher soil pH and labile C fractions making P more available, with the additional benefit of available K in these CA systems.

This paper presents the results of a study to look at CA performance of a cassava-legume cropping system in terms of yield, nutrition, and economics in Northern Zambia. They used a mother and baby trial setup  with 6 cropping systems that combined tillage (flat and bed planting) and legume intercrops (common beans and groundnut) compared to sole cassava. They measured root yield, legume yield, protein yield, energy and economic returns. See the paper for more details, but 3 treatments were planted on the flat under no-till and 3 treatments planted on hand hoed ridges (traditional system for cassava). Results showed cassava planted on the flat especially with legume intercrops under CA did not compromise cassava yield and significantly enhanced legume grain, protein, and energy yields. Economic analyses revealed higher net benefits and return to inputs in flat-planted intercrops, though labour costs were also higher.

This research from Brazil studied the SOC stocks to 1-meter deepth for 3 land uses; native vegetation (NV), no-till system (NTS) and plough based tillage (PBT) from 63 sites collecting 3402 soil samples from the Atlantic Forest biomes and Cerrado of Brazil. There was a significant loss of SOC stocks from the PBT compared to the NV treatment.  The SOC stocks of 16 NTS sites exhibited levels that exceeded those under NV, and SOC stock was restored from 80 to 100 % of its NV levels in 27 other NTS sites across the Brazilian biomes. The duration of NTS to restore SOC stock to that under NV ranged from 36.4 to 55.0 years for the Cerrado and Atlantic Forest biomes, respectively. 

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 study was done in the US upper Midwest over 3 years. There were 15 field pairs with one using conventional (CM) and the other soil health management (SH) (reduced tillage, cover crops and crop diversity). They assessed these plots by looking at soil organic matter pools, microbial indicators and a physical indicator. Wet aggregate stability improved in the SH plots compared to the CM ones. Results showed that most soil properties were significantly responsive to two management combinations, 1) tillage x cover crops, and 2) tillage x cover crops x crop diversity. Microbial indicators along with potentially mineralizable nitrogen (PMN) exhibited the strongest increases in the SH plots.

This article from Mexico evaluates rainfed, monocrop maize CA cropping systems in semi-arid areas from 2 field experiments on 17 farmer fields planted from 2013-2020. The measured yield and profitability. Maize under conventional tillage was compared to maize on permanent beds with soil mulch, either monocropped or in rotation with triticale, oats, or common beans. Results varied between the two experimental sites. In one site bed planted maize was higher than conventional (CT), while in the other field yields did not significantly differ. In the 17 farmer fields bed planting yielded 70% higher maize than under CT. They conclude that "The most profitable system was permanent beds with a maize-bean rotation in field experiments and with maize monocropping in farmers’ fields."

This paper from China looked at a 6-year field experiment that compared CA with CT on SOC fractions in a sandy soil. Compared to CT, CA increased particulate OC (POC) in the 0-30 cm soil depth and mineral-associated OC (MAOC) in the 0-20 cm depth. Tillage and soil depth had significant influences on the bacterial, fungal and protistan community compositions and structures. They conclude that the results strengthen their understanding of microbial functions in the accrual of SOC fractions, which contributes to the development of conservation agriculture on the Northeast China Plain.

The traditional rice-wheat-mung cropping system in North Bihar, India has experienced declining yields and water constraints. This paper looks at alternative tillage and crop establishment (TCE) practices to remedy this problem. Five different TCE practices were evaluated in on-farm experiments. The best yields were found with Zero-tilled direct seeded rice (ZTDSR) followed by Happy Seeder ZT wheat (HSZTW) and HS gram (HSG). This treatment also provided the highest net returns with this CA based system out-performing traditional systems.

This paper from Malawi where maize is the main staple food evaluated over 7 seasons four maize genotypes under different CA and conventional practices across on-farm communities. Results showed significant G×E and E×M interactions with hybrids such as DKC 80–53 and PAN 53 higher yielding than the other hybrid and the OPV in most of the environments. However, the OPV ZM523 variety had greater yields in environments with above-average rainfall and shorter in-season dry spells. CA practices out yielded conventional ones. Interestingly intercropping maize with pigeonpea or cowpea didn't perform as well as growing these two legumes after the maize. The recommend that smallholder farmers should adopt hybrid maize and CA-based management, although OPV's could be considered for variable climate areas.

This desktop research project reviewed the literature  on CA practices and their affects on soil health and productivity in the Midwest of USA. They looked at on-farm application of CA practices; compiled data on diverse farming systems using conventional and CA practices; and identified knowledge gaps where corn-soybean was the dominant cropping system. Major knowledge gaps were identified that need to be included in future research on farming practices that improve soil health.

This economics paper says that adoption of CA increases production while reducing GHG emissions but adoption in the developing World is low. They suggest it takes multiple years of continuous adoption for farmers to realize positive results. The paper uses an on-farm experiment in N. Ghana to identify how incentives and peer information affects adoption. They found no overall effect of peer information but found evidence that long-term adoption increased adoption especially if benefits included higher yields.

This paper investigates the effects on no-till (NT) and shallow conservation tillage (RT) in combination with cover crop mixtures in rotations with at least three different crops in on-farm experiments in Germany. Experiments were done in 18 farms and 2 experiment stations over 6 years. Yields of cereals, oilseed rape, maize, soybean and peas were slightly lower under no-tillage than under conservation tillage. Cover cropping did not affect crop yields. Tillage and cover cropping had no influence on weed control in the subsequent main crop. They conclude that CA with minimum tillage had slight advantages compared to the no-till system under their farming conditions.

This interesting paper looks at combining CA and Organic management systems in Belgium as a way to increase soil biodiversity and ecosystem services. They suggest this is a way to mitigate shortcomings in each individual system. They mention that  it is challenging, since it leaves no curative option (neither synthetic pesticides nor soil plowing) for pest control (phytophagous, pathogens, and weeds). As such this paper concentrates on restoring predatory communities, spiders and carabids. They used pitfall traps to sample these two communities in paired adjacent cereal fields conducted under organic-conservation (OC) and conventional (CV) agriculture. Their results show that OC systems are promising systems to support these natural enemy communities. They conclude studies are needed to assess whether combining organic and conservation agricultural enables sufficient pest control levels to achieve high levels of food production and farmers income.