Conservation Agriculture Research Updates - April 2026

The goal of this study was to look at the relationship of soil CO2 emissions with soil physicochemical properties from soils tilled differently in a winter wheat, summer maize rotation in China. This 4 year trial compared conventional till (CT) with no-till (NT). Cumulative soil CO2 emissions were reduced by 28.7% in maize and increased by 9.0% in wheat under NT as compared to CT. On an annual scale, the cumulative CO2 emissions were decreased by 20.5% in NT as compared to CT. NT improved the above ground biomass by 7.74% and 6.44%, and grain yields by 10.2% and 4.49% for maize and wheat, respectively. They conclude that NT can be extensively used as an eco-friendly cropland tillage practice based on its positive effects of reducing CO2 emissions and increasing crop yields.

This study investigated various Climate Smart agriculture (CSA) practices on earthworms and soil physico-chemical properties in R-W systems in IGP area of South Asia using a 10 year established experiment. There were 5 scenarios with one the farmers practice (transplanted rice- tilled wheat) used to compare with the other 4 CSA ones. The other 4 CSA ones had rice-wheat-mungbean with flood irrigation (FI) and subsurface drip (SDI) and maize-wheat-mung bean with FI and SDI. Earthworms were absent from the check scenario whereas the 4 CSA scenarios over 10 years increased EW density and biomass. The maize based CSA's had more EW's than rice based ones and Drip systems had higher numbers than flooded treatments.  They conclude that CSA-based scenarios, in particular, maize-based scenarios using SDI, improved EWs' proliferation, SOC, and nutrients storage (in soil and EWC) and showed a better choice for the IGP farmers with respect to C sequestration, soil quality, and nutrient availability.

This is another fungal community paper affected by management practices from India. It also looks at soil chemical and physical properties. It looked at various climate smart agriculture (CSA) scenarios based on CA and compared with CT in rice-wheat systems. There were 6 scenarios with CT, NT and +/- mungbean in rice-wheat and maize-wheat systems. The first 4 scenarios were flood irrigated and the last two with a subsurface drip with N as fertigation. Soil samples from 0-15cm were taken for fungal community composition. The data showed a higher Shannon diversity index of 1.47 times and a Simpson index of 1.12 times in maize-based CSA scenarios (ScIV and ScVI) compared with rice-based CSA scenarios. Soil physical, chemical, and biological properties were found better under CSA-based practices, which also increased the wheat grain yield and system yield and hence play an important role in sustaining soil quality/health.

This is paper on the rice-wheat systems of South Asia, a system where its sustainability is questioned. The paper looks at the soil physical properties and carbon pools in a 10-year CA experiment. The treatment that had triple NT in all three crops (CA5) -- rice-mungbean-wheat - with residues left on the surface resulted in higher soil aggregates than conventional tillage - puddled transplanted rice - tilled wheat. Soil infiltration rate, sorptivity, and saturated hydraulic conductivity, yields and net returns were also significantly higher in CA5 than in CT. They conclude that CA-based rice–wheat–mungbean system (CA5) would be an alternative to conventional PTR-CTW system in the Indo-Gangetic Plains of India and in similar agro-climatic situations of South Asia. 

This paper looks at Permanent Raised Beds (PRB) a form of NT on ridges and furrows for their potential to conserve soil and water resources. In this 6-year field study with a maize-wheat rotation in the North China Plains on the soil's hydraulic properties of no-tillage (NT) and traditional tillage (TT) on flat fields and no-till PRB treatments were assessed. Soil samples were taken from 0-15 and 15-30 cm depth. Total porosity and SOC under PRB were significantly improved compared to TT . Changes in the slope (b) of the soil water retention characteristic curve under the PRB treatment were indicative of an improvement in the pore size distribution, increased soil water retention, and greater infiltration rates. In addition, positive changes in lateral water infiltration from furrow irrigation were observed under PRB. They conclude that the application of PRB and the principles of conservation agriculture have potential for effective water use efficiency and for improving the quality of soil.

This long term (23 years) experiment on tillage and N fertilization in Italy looked at the microbiome in small macroaggregates (sM) and occluded microaggregates (mM) in wheat-soybean rotation. They compared two tillage treatments -- minimum tillage (shallow disk harrowing) and conventional tillage (moldboard plowing plus disking and harrowing). Soil sampling was done after 23 years.  Their results suggest that diversity and structure of microbiome is positively shaped by CA, and there are microbial taxa and network traits suitable as indicators of nutrient stocks and soil structuring under an agriculture focused on soil health.

This paper looks at how weed density, community diversity, and structure are impacted by different combinations of CA principles (NT, Mulch (M) and Rotation (R) carried out in three seasons and two soil types (clayish and sandy) for maize in Zimbabwe. At the sandy location precipitation did not affect grain yield, but positively affected weed density, diversity, evenness, and richness. By contrast, at the clay location, precipitation positively affected grain yield, but did not modify weed density and evenness, and reduced weed community diversity and richness and also weed density affected grain yield. .

This study compared  CA and Conventional (CONV) plowed fields to characterize water functioning in soils in SW France. Hydraulic conductivity (KS), bulk density and available water capacity (AWC) of the soils were measured to a depth of 50 cm on multiple dates to assess their temporal dynamics. KS was higher under CA. There was less temporal variability for infiltration under CA. Under CONV infiltration was higher after plowing but decreased rapidly after that. AWC was higher under CA on the surface (5cm) but the difference with CONV was small through the soil profile. However, the rooting depth was higher under CA allowing better use of the soil profile water.

This paper explores the impact of Climate Smart agricultural practices (CSAP) on farms in Haryana, India. They looked at ZT, residue retention and crop diversification and measured soil chemical and physical properties from 0-20cm, and GHG's comparing CSAP to conventional (CP) grown with wheat. Of the 70 farmers, 22 followed CSAP's and 48  CP's. Results showed that soil pH was lower (7.76) for CSAP farms compared to conventional practices (7.99). Soil carbon in CSAP was also higher as were total organic carbon stock and total carbon compared to CP. CA registered similar to 31% higher soil quality index over CP and wheat yields were higher. GHG emissions were similar to 63% higher in CP compared CSAP. CSAP not only improves soil carbon pools, but also improves the overall quality of the soil.

This article looks at the impact of conservation tillage in maize in the Karst rocky region of SW China where desertification is a serious environmental problem. This 2-year study compared no-till + straw cover against traditional tillage (TT) in maize on soil properties and yield. The NT treatment increased soil moisture by 3% while reducing bulk density by 7% and total N by 5% in the top 30cm compared to TT. Nt treatments also increased maize yield by11% compared to TT. They conclude that NT + residue retention is  better for long-term environmental sustainability in the arid region.

This 4-year study looked at the effect of different tillage practices and cropping systems on total organic carbon fractions and water stable aggregates in the EGP of India. there were 3 rice cropping systems, and three tillage practices -- CT, RT and RT with 30% residue retention RTR30. The Rice-lentil, RTR30 had the highest carbon stock, TOC, organic fractions and aggregated associated organic carbon. However, RT treatments had increased macro-aggregate size and its associated carbon suggesting a high potential for carbon sequestration reducing carbon loss by reducing tillage.

This paper used a meta-analysis of 89 articles to identify changes in soil aggregation and aggregate-associated soil organic carbon (SOC) at the global level. They looked at climatic conditions, experimental duration, cropping intensity, soil texture, and initial SOC/pH) in the changes in those 2 variables. Compared to conventional tillage (CT) No-tillage (NT) increased water stable large (LM) and small (SM) macro-aggregates and mean weight diameter (MWD) but decreased micro-aggregates and silt plus clay-size particles (SC). NT significantly enhanced SOC concentrations in LM (17%), SM (14%), MIC (10%), and SC (7%) compared to CT. The random forest (RF) model demonstrated that climatic conditions, experimental duration, and soil texture were the predominant factors controlling the changes in aggregation and aggregate-associated SOC under NT. The conclude that NT helps improve soil structure and SOC sequestration, ultimately controlling soil degradation in croplands.

This paper looks at residue management that is difficult to manage in modern agriculture without burning and can lead to late planting. This paper looks at zero-till residue management on soil health parameters in a maize-chickpea pattern in the black vertisols of India. After 4 years the soil bulk density was reduced by 3.0–10.2% and volumetric moisture content was improved by 10.2–19.3% at 0–10 cm soil depth in ZT with residue over conventional tillage (CT). Organic carbon and labile carbon,  P and K, total fungal and actinomycetes were also increased compared to CT at 0-10 cm soil depths.

This paper looks at low soil disturbance system on deep soil functioning. They compared the soil bacterial communities and physicochemical parameters across 3-m deep soil profiles in a Mollisol of Northeast China at the end of the dormant season after 10 years of farming under conventional tillage without stover mulching (CT), no-tillage without stover mulching (NTNS), and no-tillage with stover mulching (NTSM). The two low disturbance treatments promoted more soil bacterial species richness and diversity compared to CT. No-tillage alone homogenized the composition of the bacterial community through soil depth profiles, but straw mulching enhanced the uniqueness of community composition at each layer. Compared to CT, NT with residue increased soil water content and root associated organic carbon and decreased pH. More mineral N in the 0-150cm zone in NT systems than CT where N was lower in the profile. They conclude that low-disturbance practices can regenerate whole-soil bacterial diversity and potential function, and promote water retention and nitrogen holding capacity within the root zone.

This long-term study looks at the impact of various tillage and cover crop systems on soil structure and hydraulic properties. Water retention and conductivity curves for the 0-5cm and 20-25cm soils were made. Dynamic water storage and retention were evaluated using numerical simulations in HYDRUS-2D software. Soils under no-till (NT) and cover cropping (CC) systems showed improved soil structure in terms of pore size distribution (PSD) compared with CT and no-cover-crop (NO) and hydraulic conductivity ( K) under these systems led to an increased infiltration rate and water retention. NT and CC plots had lower water content at field capacity and lower plant-available water compared with ST and NO plots. However, NT and CC plots had higher water storage (albeit marginal in magnitude) and water availability following irrigation.

The objective of this study was to determine spatio-temporal dynamics of soil hydraulic properties and pore characteristics on a silt loam long-term tillage field experiment, in NE Spain, during two cropping years. Undisturbed soil samples were used to determine soil water retention, and soil hydraulic conductivity curves in two different tillage systems (intensive tillage, IT vs no-tillage, NT), two crop sequences (short fallow-maize, FM vs legume-maize, LM) and two positions (within the crop row W-row vs between the crop rows B-row). This study shows that LM increases specific hydraulic conductivity of soil macroporosity by increasing the number of effective macropores and the effective porosity. Further, long-term NT formed a stable number of effective macropores and coarse mesopores, and showed a greater pore continuity in coarse and fine mesopores, resulting in improved soil water flux.

This paper reports on the rice-maize system in Bangladesh, an expanding system in this country. Traditionally, this systems cultivates puddled transplanted rice followed by tilled maize. This is labor intensive, reduces soil health and is less profitable. As such, a field study looked at conservation agriculture (CA) based tillage and crop establishment (TCE) techniques and residue management practices on the physical, chemical, and biological properties of soil along with crop productivity and the profitability of rice-maize systems in the sandy loam soil of Northwest Bangladesh. The authors concluded that CA could be an appropriate practice for sustaining soil fertility and crop yield under R-M systems in light-textured soils or other similar soils in Bangladesh. 

This field experiment had three treatments 1) no-till or rotary tillage under the maize-wheat-soybean-wheat system (NT-MWSW, RT-MWSW); 2) no-till or rotary tillage under the maize-wheat system (NT-MW, RT-MW), and 3) no-till or rotary tillage under the soybean-wheat system (NT-SW, RT-SW)] in the North China Plain (NCP) to assess their effects on aggregation and SOC. Results showed that macroaggregates (> 0.25 mm) were the main contributors to the soil carbon (C) pool. NT increased not only the proportion of macroaggregates but also aggregate stability. Significant positive effects from soybeans were observed under NT. The conversion rate of straw C input under NT-SW was higher than that in other treatments. The total potential mineralization of macroaggregates under NT legume-based crop rotations was higher than that of MW.

This paper reports the results from a 9-year field study on a wheat-maize-soybean rotation in Italy where NT combined with grassy and legume cover crops (CC) were studied in terms of yield, C and N input from the main and cover crops, soil aggregation, and C and N sequestration rates in comparison with conventional tillage (CT). They showed that yield of winter wheat, maize, and soybean were never reduced under both NT treatments, neither during the transition phase, nor afterwards. Rye and hairy vetch provided the same amount of biomass and C input, although vetch doubled N input compared with rye. Both NT plus rye or vetch promoted C and N sequestration mainly due to increase in macroaggregate associated C and N. They conclude that since there was no difference between cover crops in terms of biomass input, and C and N sequestration potential, that cover crop biomass production (rather than biomass quality) and retention onto the soil as residue were the main drivers of soil C and N sequestration. 

This paper highlights the importance of soil health and reviews the literature on the role of CA in improving soil health. They suggest that conventional agricultural practices cause deterioration in soil quality, increasing its compaction, water erosion, and salinization and decreasing soil organic matter, nutrient content, and soil biodiversity, which negatively influence the productivity and long-term sustainability of the soil. They conclude that CA can reduce the negative impacts of conventional agricultural practices on soil health while conserving the production and provision of soil ecosystem services.

This study used 6 plots using CA installed in 1984 in Uruguay to quantify changes in soil quality contribute to current runoff and soil erosion in a cropping system under soil conservation practices - NT, residue retention and cover crops. Plots were grouped in three treatments with contrasting historic index of agricultural intensification (IAI). The IAI was developed combining the duration of land use under agricultural production and the number and intensity of tillage activity resulting in the treatments: tillage with crop-pasture rotation (TIL_CP), no-tillage under several rotations (NT_Mix) and tillage with continuous cropping (TIL_CROP) with an increasing IAI of 3.5, 7.1 and 11.8, respectively. Rainfall events, runoff water and total, fixed and volatile solids were studied from 2017 to 2019. Soil physical and chemical parameters were measured. The lowest soil losses were observed in TIL_CP. They conclude that CA minimized soil erosion losses in all plots and years, and erosion was much lower than the maximum tolerable threshold of 7,000 kg/ha for this particular soil.

The aim of this paper is to look at the effects of fallow in the off season and grass/grass and grass/legume crop successions on soil aggregation in NT systems. The study was done on fields with different land uses for more than10 years in SE Brazil. Three NT maize land uses yielded 3 groups: NT- with  fallow in the off season; NT with legumes in off season; and NT with maize in the off season. Forest land (F) was used as a check for soil aggregation and CT a a low conservation system. They found that the absence of soil surface cover throughout the year in an NT system was as harmful to soil aggregation as a CT system. The NT-grass system resulted in higher organic C and aggregate stability than the NT-legume system. They also found that that fallow in the off-season promotes a NT system with low soil conservation.

This study aimed to assess after 26 years the long-term effect of conventional tillage (CT) and no-tillage (NT) combined with winter cover crops, black oat and oilseed radish, and fallow on C accumulation and stabilization in a  clayey Oxisol in Southern Brazil. Soil samples were collected from 3 depths. NT had a higher percentage of macroaggregates and C stock in this size-class, and also higher C stock in bulk soil, free-POM and occluded-POM fractions than CT in 0-0.05 m depth due to higher input of biomass and minimum soil mobilization in NT. Oat and radish had higher C stock in macroaggregates than fallow in 0.05-0.10 m depth. They conclude that after 26 years of NT improved C accumulation and stabilization, mainly in the superficial layer. Also winter cover crops favored the formation and stability of macroaggregates.

This paper reports on a field experiment in the middle IndoGangetic Plains of India to determine if CA can arrest soil fertility decline and improve production in this area. They tested 4 common farming practices that had different tillage, seeding, residue management, and crops. After 7 years, 3 systems lowered Bulk Density and compaction, and higher soil macro-aggregates compared to the conventional check.Avoiding tillage in wheat and including a food legume in rotation increased annual rice equivalent yields by 30.5-34.4%. NT and retention of crop residues had potential to improve soil health and monetary gains.

This study looks at tillage intensity, crop residue management and green manure (GM Sesbania) on SOC within micro- and macro-aggregates after 6 years of growing rice-wheat in India. The plot treatments included ZT and CT with and without different % of residues and with and without GM. The ZT with 100% rice residue  (ZTWR100) significantly increased soil moisture retention compared to CT w/o residue (CTWR0) and also increased the dehydrogenase (DHA), cellulase, and β-glucosidase activities and the easily extractable glomalin (EEG)- and total glomalin (TG)-related soil protein compared with the CTWR0 treatment. Crop residue retention plus GM significantly improved the proportion of total water-stable aggregates (WSA), mean weight diameter (MWD), and aggregate ratio (AR), compared with the treatments involving residue removal and no GM.