Conservation Agriculture Research Updates - April 2026

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 from Brazil looks at the role of cover crops to improve soil fertility, plant nutrition and soybean yield in the Cerrado area in a dryland area. There were 8 cover crops, and fallow preceding soybeans grown in the off-season. This area had cultivated soybeans under no-till for 10 years. They measured the biomass of the cover crops, but also soil chemical and biological properties, soybean foliar nutrients, yield and quality. Data can be found in the paper and abstract. They concluded that "Cover crops improved soil fertility while increasing soybean productivity, thus being an effective strategy for the achievement of sustainable soybean production."

This 4-year study in the Lower Mississippi Delta on farm size plots compared soybean yield and soil health benefits comparing CT with NT. Both plots were under maize for 11 years prior to growing soybeans using CT and NT soil management for each plot. Results showed that NT compared to CT, in the 0-20 cm layer, increased soil bulk density (rho), total nitrogen (TN), and soil organic carbon (C) but field-saturated hydraulic conductivity (Kfs) decreased in the 10 cm below the soil surface under NT. Yields of soybeans over the 4 years were similar for CT and NT plots. But NT resulted in less expenses without affecting soybean yields.

This paper from Canada looks at application rates of Glyphosate (GBH) to terminate cover crops and how this influences soil microbial communities. They used 3 GBH application rates in maize, soybean and wheat fields grown with direct seeding (NT) with and without cover crops. Results showed that DS+CC did not significantly impact microbial richness compared to DS, but did alter specific abundance among prokaryotes and eukaryotes but that the three crops significantly influenced the composition of eukaryotic communities in 2018 and 2019, but not prokaryotic communities. They conclude that the study calls for sustainable agricultural practices that preserve microbial diversity, which is essential for maintaining ecosystem services and soil health.

This study used multiple satellite-derived indices and environmental drivers to infer the level of tillage intensity and identify the presence of cover crops in eastern South Dakota using  environmental drivers acquired from different remote sensing datasets for 2022 and 2023 to map conservation agriculture practices. They successfully detected the presence of cover crops and the tillage intensity in the study region. Their analysis shows the percent use of cover crops in maize and soybeans and adoption of CA tillage practices. This approach benefits both public and private sector organizations by enabling them to track landscapes remotely and efficiently. This, in turn, can incentivize farmers to adopt conservation practices, contributing to climate change mitigation efforts and fostering sustainable agricultural development.

In Brazil soil and water conservation has made no-tillage the leading method for preparing land. This paper looks at the adoption rates of NT and CA within Parana State farmers using data from the Brazilian Institute of Geography and Statistics' censuses from 2006-2017. Data shows a rise in the adoption of NT from 68.5% to 78.9% and CA from 14.6% to 27.7% over this time period. The highest rates were in areas where soybeans, maize and wheat are grown. The lowest in areas where pasture, sugarcane, cassava and rice are grown.

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 paper reports on a field study to assess the productivity, soil health and carbon dynamics of a soybean-wheat system under 4 tillage and residue management treatments (TRMPs); 1) CT w/o residue, 2) CT + residue in both crops, 3) NT w/o residue, and 4) NT + R in both crops. Also 5 organic-nutrient practices (ONMPs). Among the TRMPs, NT +R improved system productivity compared to CT - R. They conclude that the soybean-wheat NT + R at 6 t ha−1 year−1 + NF-based ONMPs (N5) harness higher and sustained productivity under this cropping system while improving soil-health and soil carbon-pools in sandy-loam soils of the north-Indian plains and similar soils across south-Asia.

The paper suggests that the increase in carbon sequestration under long-term NT and cover crop management is a sustainable agricultural system with an increase in SOC and soil respiration. This study looks at the addition of biochar on soil respiration in Japan. Long-term tillage practices, such as NT and moldboard plowing (MP), cover crops such as rye (RY) and fallow (FA), and biochar application such as with biochar (WB) and no biochar (NB) were applied to a split–split plot in a randomized complete block design with four replications. NT had higher respiration compared to MB. Rye had a higher respiration than fallow. Biochar significantly reduced respiration in the soybean and cover crop growing seasons but enhanced carbon sequestration. It reduced respiration by regulating the soil temperature, soil moisture and protect the SOC from decomposition. Biochar also increased SOC, decreased bulk density that improved soil porosity.

This article looks at the role of crop rotation on soil aggregation and associated organic carbon (OC). The used 2199 paired observations from 53 studies to elucidate the rotations role in soil aggregation and associated OC and to identify optimal climatic, edaphic and agronomic factors. Overall, rotation improved aggregate and OC contents in all aggregate classes compared to monoculture. Greater increases in soil aggregation and associated OC induced by crop rotation were associated with sub-soiling, no-till, straw retention, combined manure-inorganic fertilizers, and a lower nitrogen fertilization input rate with more rotation cycles and longer rotation length. Climate and initial soil OC were important for the benefits of rotation. They conclude rotation is important for the sustainability of agroecosystems.

This paper looks at organic agriculture using NT combined with rye cover crop in Japan. They looked at carbon footprint (CF) and energy efficiency in a soybean crop. There were 3 tillage treatments: Moldboard (MP), rotary tillage (RT) and no-till (NT). The two cover crop treatments were fallow and rye. Over 4 years, the NT had significantly lower energy input than MP or RT, but had lower yield of soybean. But using the rye CC resulted in mitigation of NT yield of soybean. NT-Rye increased SOC by 3.5%, less CO2 emissions and had the lowest CF. They recommend NT+RyeCC in organic agriculture. Note that NT without residues is often not as good as NT with residue cover. This study confirms this.

This integrated crop and livestock system  (ICLS) research evaluated the the impact of NT together with ICLS on soil health and soybean yield in Southern Brazil. Soil physical, chemical, and biological soil health indicators were measured over the short term (<5yrs) and long term (>10yrs) under ICLS with soybean in spring/summer and forage grazed by cattle in the autumn/winter. A Soil Management Assessment Framework (SMAF) was used for a soil quality index. Overall, the adoption of ICLS in association with NT (i) improved or maintained soil health, (ii) promoted soil carbon sequestration.

This paper reports on a 44-year long term field experiment looking at yield, yield stability and adaptability of continuous wheat (Ct-W), soybean (Ct-SY), and grain sorghum (Ct-GS ) plus soybean-wheat (SY-W) and soybean-sorghum (SY-GS) rotations under 3 tillage treatments - NT, RT and CT. Crop rotation consistently outyielded continuous cropping, and the advantage was enhanced when integrated with NT but yield stability decreased under NT continuous cropping. Soybean had higher yields under rotations and NT with similar yield stability. They conclude that there were advantages to crop rotation combined with NT.

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 study from Poland looked at various tillage methods and their impact on soybean yield and quality. The four tillage methods were: a) Plowed tillage plus conventional row seeding (PCR); b) Plowed tillage plus strip till planting (PSD); c) No plough tillage + strip drill planting (NSD); and d) No-tillage + strip drill (ZSD). The paper presents the data on these 4 treatments. ZSD enhanced protein levels and stabilized protein and fat yields. They conclude that future studies should explore how tillage practices affect soil health, economic sustainability, and yield stability over time, especially under changing climatic conditions.

This paper looks at land in the Lower Mississippi Delta where 70% of the land is furrow irrigated and where NT and bed planting issues hinder NT adoption. Ridge making and furrow maintenance are crucial in this area. This paper looked at the impact of adopting long-term NT compared to conventional tillage (the traditional system). NT increased soil total nitrogen, organic matter, organic sulfur, magnesium, calcium, cation exchange capacity, and stored soil water compared to CT during 4 years of soybean production following 11 years under corn. CT resulted in loss of nutrients as a result of disturbing the soil surface. CT also developed a thick plow pan at 10cm depth. I wonder if they should think of having permanent NT beds with residue retention that is practiced successfully in other parts of the World.

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 paper from China assesses the balance between productivity and environmental impacts to find ways to reduce the threat of GHG emissions and climate change. They had 8 treatments that include 2 key components: the evaluation of economic and environmental parameters encompassing carbon footprint, energy consumption, and the carbon sustainability index. The results showed the benefits of no-till treatments (NT) coupled with introduction of soybeans in a rotation compared to conventional tillage (CT). However, the CT-MW treatment had the highest yield: combining conventional tillage with minimum tillage practices. Despite the higher cost to grow soybeans, their use increased net income. They conclude that the adoption of conservation agriculture optimizes the delicate equilibrium between environmental preservation and economic prosperity. 

This study, initiated in Canada in 1992, evaluated the effect of 25 years of N and P fertilizer application and tillage (Moldboard vs No-till) on density, biomass and composition of weeds before and after herbicide application in maize (2016) and Soybean (2017). It also evaluated the same treatments 6 years later in maize (2022). comparing  weeds found in 2004 all weed variables increased and there were more grassy weeds in both tillage treatments. No fertilization effect was observed on any weed variables, including composition, except for increased biomass when left to grow all season after crop planting. No till had higher density and biomass of both annuals and perennials before herbicide application but only reduced yield in soybean.

This study looks at the willingness of Canadian farmers in Quebec to accept compensation (WTA) fr adopting a direct seeding, mulch based cropping system (another name for CA?) (DMC). Their results show that their famers would demand 161 C$/ha to convert to DMC although they are only willing to convert 25% of their farm to DMC. I wonder if compensation payments to encourage farmers to adopt DMC is a good idea, but the paper discusses to reasons for reluctance or choice to do so. They end that more research is needed.

This South Dakota study assessed the impact of tillage CT and NT); crop rotation: 2-year corn-soybean, 3-year corn-soybean-oat and 4-year corn-soybean-oat-wheat; cover crops (cover crop [CC] and no cover crop [NC]); and drainage (tile drainage [TD] and without drainage [ND]) on soil organic matter (SOM), bulk density, wet aggregate stability (WAS), and field-saturated hydraulic conductivity (Kfs). Soil samples were collected over 2 years from five depths and analyzed for SOM, bulk density, and WAS. NT increased soil bulk density, soil organic matter, and wet aggregate stability (WAS) for the 0- to 10-cm depth but decreased Kfs within the soil profile compared to CT. CC and tile drainage(TD) had minimal impact on SOM, bulk density, WAS, and Kfs.

This paper looks at the role of interseeded cover crops (CC) to improve water storage, reduce runoff, increase infiltration and decrease evaporation. The paper reports the effect of interseeding CC in 4 NT rotations by USDA. All rotations included, maize, soybean and wheat. They also used different cover crops. Estimated evapotranspiration was lower for CC compared to NC systems in 2018, while greater estimated infiltration was observed for CC compared to NC systems in 2019.4-year averaged maize yields and WUE were higher in CC than NC. The returns from better yields offset the costs of establishing CCs. They conclude interseeded CCs in humid area of US is beneficial.

The increase in use of CA practices (NT, residue, cover crops) in North America has in some cases resulted in an increase in damage by slugs. This paper tested the use weather and natural enemies on slug activity in 41maize and soybean fields in Virginia. They found that a positive effect of cover crops on slug activity-density was reduced by tillage and that slug activity-density declined with increasing ground beetle activity-density. Slug activity-density also declined with decreasing rainfall and increasing average temperature. They conclude that practices that promote recruitment of ground beetles in crop fields can improve natural suppression of slugs in corn and soybean that are being increasingly cultivated using conservation agriculture practices.

The authors suggest that NT is a sustainable agricultural practice providing yield and environmental benefits. But they suggest economic concerns are a barrier to adoption. As such this paper evaluates the long-term economic benefits of NT adoption using a LT field experiment that ran from 1996-2019 in Maryland, USA. Their results suggest there are no long-term differences between NT and CT using maize, soybean, and wheat. But partial budgeting analysis suggests net returns from NT are greater than CT in all 3 crops. Mainly a result of lower operation costs. They also suggest that the profitability of NT increases over a longer time of adoption. The paper does not mention what happens with the previous crop residue, an important factor for NT since data suggests NT with a permanent residue mulch yields better than NT without residues.

This paper looks at growing maize intercropped with ruzigrass (Urochloa sp.) on soil physical properties over three years including maize and soybean yield under no-tillage and rainfed conditions. There were three intercropping systems; ruzigras sown  before maize; sown at the same time; and sown 15 days after maize. Soybeans were grown every summer. Soil physical properties included bulk density at 10-20cm, and macroporosity and were better when ruzigrass is sown before maize. Soybean yields were not affected two of the three years nor by soil physical properties. Maize yielded 17% more when ruzigrass was planted 15 days after maize than before maize.