Conservation Agriculture Research Updates - April 2026

This study evaluated the effect of NT compared to moldboard (MB) with rye CC versus fallow on SOC and active C, aggregates and other soil physical properties. Rye significantly increased aggregate-associated C. NT combined with RY significantly increased SOC and AC in the surface layer and volumetric water content at all soil depths. The results showed that the NT system increased plant residue, reduced soil evaporation, increased SOC content and soil water retention, and bonded soil microaggregates into macroaggregates better than the MP system. NT plus rye CCs reduces drought effects that result from climate change.

This article looked at soil aggregation and concentration, mineralization, and thermal stability of aggregate-associated C under CA with different rates of crop residue (CR) retention and nutrient management practices in a 6-year-old experiment in India. There were 3 residue levels, 0, 2 and 4 t/ha and 6 levels of N + K. The highest residue retention had highest cumulative C mineralization, but the lowest percentage and decay rate (K-c) of SOC mineralization. Their results show less temperature sensitivity of physically stabilized SOC under CR4 (4t/ha) therefore emphasizing the effectiveness of using complete CA practices like NT and residue.

This recent, available, valuable on-line paper emphasizes the critical nature of soils for agriculture and natural ecosystems that need to be protected. The paper describes how nature manages resources and management guidelines for "living soil". The paper promotes CA as a management system to achieve this protection. It explains why tillage is detrimental to soil health (SH) and how it destroys soil biological, physical, chemical, and hydrological properties. It concludes that in 2018/19, CA was practiced on more than 205 million hectares across more than 100 countries. That the impacts of climate change and tillage on food production and environmental degradation require the application of nature-based solutions as Conservation Agriculture.

This article suggests that conventional farming with intensive tillage and residue burning results in substantial degradation of soil health resulting in declining crop productivity of maize. A field experiment looked at NT with stubble residue mulch for 3 years compared to CT with residues or ridge tilled maize. The results showed that NT with residue consistently out yielded the CT and ridge tilled systems. In addition the traditional practice of stubble burning in all systems substantially reduced grain yields. Soil health improved in all NT + residue treatments compared to CT and ridge-till in terms of soil porosity, electrical conductivity, hydraulic conductivity (HC), available soil moisture, soil organic carbon, soil N, P and K content. They concluded the importance of switching to NT but with residue retention.

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 chapter 3 in Advances in Agronomy starts by explaining the problems with meeting future food demand that is further complicated by climate change. The suggest that CA is a solution for meeting these challenges that include soil health, climate change, water scarcity, pollution, farm profit and human health. The paper reviews the published data in South Asia to assess the impact of CA in meeting these challenges. The results from several studies demonstrated that CA increased SOC and improved soil health parameters, mainly in the surface soil layer and also had a positive impact on nutrient availability in the soil. The chapter also outlines the knowledge gaps in soil health assessment and recommend that more research on soil health is needed in the future.

This paper analyzed two 6-year long component omission experiments on two different soil types (sandy and clay) in terms of soil chemistry, residue decomposition and arbuscular mycorrhizal fungi (AMF) colonization of maize roots. Soil chemical properties only differed across systems in the sandy soil mulched systems under no-tillage (NT) resulting in increased soil organic carbon levels, total nitrogen, and soil available phosphorus as compared to conventional tillage with no mulch or rotation (CT). Systems with NT and rotation resulted in highest AM fungal root colonization rate of maize at the clay soil location. Total plant N uptake was almost 2-fold higher in tilled and no-tilled systems with both mulch and rotations. They used  structural equation modeling to disentangle the links between cropping systems, soil chemical and biological properties, plant nutrient uptake, and maize grain yield. They conclude that a more holistic approach to cropping system assessment that includes a higher number of abiotic and biotic determinants is needed to evaluate the drivers of yield. .

This review paper from Bangladesh looks at the inclusion of legumes in rice based cropping systems where there is increased risk due to water, energy, labour and capital scarcity, which are exaggerated due to the effects of climate change. There is also a loss of soil health, groundwater depletion, and reduced water and land productivity that threatens food security. They suggest that CA with inclusion of legumes may be a solution. They list some of the benefits of including legumes in rice-based systems. They conclude that sustainability improvements can be made by researching the inclusion of legumes in rice systems of Bangladesh.

This global meta-analysis paper of 91 studies in cropland ecosystems, evaluated the effects of no-tillage on soil aggregates and their associated SOC and TN concentrations. On average, no-tillage significantly decreased the proportions of microaggregates (MA) and silt+clay size particles (SIC) and increased the proportions of large macroaggregate (LA) and small macroaggregate compared to those in conventional tillage. The SOC concentrations and total N for all three aggregate sizes increased significantly with no tillage. They conclude that no-tillage enhances the formation of soil aggregates and the associated SOC and TN concentrations in global cropland ecosystems.

This paper looks at the problems of conventional tillage (CT) in semi-arid regions of Morocco that include exposing soil that is already fragile to degradation. The objective of this study is to assess the role of CA to address the soil physical properties compared to CT and reverse soil degradation. Results show that most of the physical properties were improved with CA in both locations. SOM also increased under CA. They recommend that CA be encouraged in this semi-arid area.

This is the second paper selected by this author that looks at degradation of soil hydro-physical (SHPs) properties following poor land management. The study looked at influence of land-use conversion from native forest land to subsequent agricultural practices on SHPs in India's N-W Himalayan area. The infiltration rate and soil hydraulic conductivity of surface soil were investigated for a sal forest, conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT). The forest land use showed the highest value followed by ZT, RT, and CT. They conclude that while conversion of native forest land to conventional agriculture degrades SHPs, these may be progressively recovered in the Himalayan region by adopting conservation agriculture strategies.

This is another article looking at CA combined with agroforestry (CAWT) in smallholder farming in Kenya. CAWT is an agroforestry system that integrates legume trees and shrubs into cropping fields under minimum soil disturbance and tillage. The paper looks at key soil quality indicators (SQI) under CAWT. The research assesses the effects of CAWT components; tillage (CT or NT), leguminous trees/shrubs (Calliandra calothyrsus, Gliricidia sepium and Cajanus cajan), and their inter-row spacing (1.5 m, 3.0 m or 4.5 m) on SQI in the dry-land agroecosystems of eastern Kenya. They conclude that a shift towards CAWT showed evidence of improving soil quality, nutrient availability and increasing soil nutrient thresholds that can potentially support maize production.

This study looks at the potential impact of drought predictions on a faba bean crop, and evaluates the adoption of conservation tillage practices to reduce this effect in dryland areas of Spain. It sampled a long-term trial that was started in 2008 and looked at soil water storage (SWS), crop productivity and mineral nutrition, plant ecophysiology and biomass quality, as well as the colonization of roots by arbuscular mycorrhizal fungi (AMF) and symbiotic Rhizobium bacteria. It sampled the non-tillage (NT), reduced tillage (RT) and traditional tillage (TT)- and rainfall reduction treatments. The percentage of biomass yield reduction by rainfall exclusion was 30% for NT, 50% for RT and 20% for TT. They conclude that, despite no effect on soil water storage, in the conservation tillage systems the increase in the mycorrhizal colonization in roots, particularly under NT, could be beneficial for plants to face drought stress. However, in a scenario of reduced rainfall it will be necessary to invest more resources in weed control under RT.

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.

No-tillage (NTR) with residual plastic mulch is being adopted in arid regions of China to reduce plastic residue, soil disturbance, and improve water use efficiency (WUE). They compared conventional tillage (CTN) and NTN with new plastic mulch with those of 1,2 and 3 years of NTR on soil physical, soil water, maize root and shoot growth, yield, and economic benefits. They showed that the longer duration of NTN and NTR, the higher the bulk density and lower soil porosity compared to CTN in the 0-30 cm depth. Read the paper for more results. They conclude that NTR for 2 years can be recommended and help reduce the problem of plastic residue while increasing economic benefits.

This article emphasizes the importance of soil health for achieving agricultural resilience, food security and mitigating climate risks. It explains that ultimately it is farmer voluntary decision making that determines what steps are taken to improve SH. This research draws upon qualitative interviews with 91 farmers across three key agricultural states in the Midwest (Illinois, Indiana, and Michigan). They develop a more detailed understanding of farmers' views on SH, and why and how they manage to achieve it. Most farmers view SH favorably with only a few not familiar with what it means. Overall, farmers' perceptions of SH largely aligned with the scientific community's understanding of soils being a dynamic system, though farmers most dominantly defined SH by its biological component. They conclude that achieving better SH in agricultural production in the future will require engaging farmers in SH management by tailoring outreach and communication strategies to align with the perspectives and language farmers themselves use to conceptualize SH.

This paper looks at the long-term effects of CT and NT tillage on chemical and physical mechanisms for SOC stabilization and accumulation in soils in after 23-years of continuous NT in southern Brazil. Data was collected from soils sampled from 0-100 cm depth and used soils from native vegetation (NV) as a check. When NV was converted to agriculture SOC stocks decreased by -33%. A comparison of NT and CT showed that NT resulted in higher SOC stock in the 0-5 and 5-10 cm soil layers and higher SOC in the entire topsoil (0-20cm). Below that both tillage systems had similar SOC levels. Adoption of NT increased the proportion of large macroaggregates in the 0–5 cm soil layer, resulting in a greater mean weight diameter (MWD) than under CT. They conclude that the pathway for SOC accumulation in the topsoil of NT is influenced less by selective preservation but driven by the maintenance of labile organic compounds, a process achieved by the low turnover of large macroaggregates in the NT system. 

This paper looked at 8 integrated crop management (ICM) practices for 6 years in a direct seeded rice-NT wheat rotation. There were 4 treatments with traditional practices and 4 with CA practices; residue retained and not retained treatments; raised bed and flat treatments. The CA-based treatments outperformed the CT practices for yield, soil quality index, and reduced carbon footprints. They conclude that the CA-based ICM practices proved to be environmentally safer and cleaner and can sustain the food and soil security of the extensive rice-wheat rotation under South Asian ecologies.

The paper stats by explaining the negative impacts of conventional management on degradation of soils and loss of soil health. The research looks at ways of reversing soil degradation using CA in a long term experiment (after 8 years) with 4 cropping systems, and three tillage systems; CT, RT and NT. Soil samples were collected from 3 soil depths; 0-10, 10-20 and 20-30 cm depths and data collected on soil chemical, physical, and biological properties in a Vertisol in Central India. @0 soil properties were used to calculate soil quality indices (SQI). The paper lists the results of this research. They conclude that the soil quality index was significantly highest in NT, followed by RT and CT at all soil depths. CA based practices favoured carbon storage, lowered carbon emission, foot print and soil quality compared to conventional farming. 

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.

This is a review article that discusses the importance of conservation agriculture as a long term approach for sustainable food security and a way to reverse issues of depletion of natural resources caused by long-term us of traditional tillage. The paper discusses the benefits of CA for improving the soil physical, chemical and biological properties and reversing SOM decline. They suggest that one sustainable cropping method that may reverse soil erosion, increase crop output, and improve the socioeconomic status of small landholder farmers is conservation agriculture (CA). The paper highlights the benefits and limitations of CA and various challenges in the adoption of CA.

This paper from New Zealand looked at various tillage options with and without irrigation on SOC, fungal biomass and their relation to to soil aggregate sizes in a 14-year experiment. They hypothesized that long-term irrigation and intensive tillage would negatively affect soil aggregation. The experiment was started in 2003 and data taken in 2017. Two tillage treatments were intensive tillage (IT) to 20-25cm compared with no-till (direct drill - DD) and irrigation was sprinkler and none (rainfed). Soil samples (0-5 cm layer) were analyzed for pore size distribution, specific surface area and microbial biomass. Sieving was also used to separate macro- (LM) and micro-aggregates (SM), particle sized silt + clay and fine particles. Both DD and rainfed management increased total SOC content of the bulk soil. The LM and its SOC increased in DD compared to IT. A higher fungal:bacteria (F:B) ratio was generally accompanied by a greater LM fraction and mean weight aggregate diameter, highlighting the importance of fungi in the formation of LM. They concluded that detrimental effects on soil aggregation by tillage and irrigation was not conclusive and a longer study period is needed to confirm.

This editorial article discusses the crucial issue of future Global food security and the need increase production by 70% to feed the 9.7 billion people estimated to fed in 2050. An FAO publication estimated that 768 million people were hungry in 2021. The author also mentions that the issue is made more difficult by the coronavirus pandemic, regional conflicts, and global environmental changes affected by climate change. The paper discusses various needs to attain food security goals including management of soil resources by sustainable means, supply and integrated management of soil nutrients such as nitrogen and phosphorus for sustained crop yield, and promotion of conservation agriculture practices to protect the environment while increasing food production. Climate change such as severe drought and increased flooding poses a serious challenge to soil manage-ment, and farmers must adapt to these changing environmental conditions by adopting climate- smart soil management practices.

This study summarizes the results of physical and mechanical soil parameters obtained over the initial 10 years of different conservation management treatments (plowing versus reduced tillage with and without compost application) in an organic field trial conducted in central Germany that looked at the effects of soil conservation measures on soil's physical quality. Differences were mainly found in the topsoil with total porosity, and air capacity lower and bulk density higher in reduced tillage treatments compared to plowed ones. However, the mechanical stability was higher in reduced tillage systems with compost additions. They conclude that the reduced-tillage treatments did not exceed the critical physical values of the soil, nor affect the functionality of the soil (saturated hydraulic conductivity), thereby demonstrating its feasibility as a sustainable technique for organic farming. They also suggested that future studies should include measures to ameliorate compaction zones in reduced-tillage treatments by applying sub-soiling especially under dry soil conditions when reduced or no-tillage is first adopted. .

This study looked at three tillage practices and four maize based cropping systems on physical hydraulic properties in a sandy loam soil in NW India from a long-term 10-year experiment. The three tillage treatments were conventional (CT),  no-till (NT) and permanent raised beds (PB). The hydraulic properties were derived from infiltration rates. Results showed that the bulk density (BD) of the soil under conservation agriculture (CA) practices (PB and ZT) were significantly lower than that in CT practices. The BD in the maize-chickpea-sesbania cropping system was the lowest of all the cropping systems. The soil aggregate mean weight diameter (MWD) and hydraulic conductivity under PB and ZT were higher than in the CT treatments. Among the cropping system choices, M-W-mungbean was more effective in improving the soil's hydro-physical properties in the study area.