Conservation Agriculture Research Updates - October 2025

This review documents the current knowledge of ecosystem services for key management practices based on experiences from agricultural lands in sub-Sahara Africa (SSA). Here, practicing conservation agriculture (CA) and Integrated Soil fertility management (ISFM) have overall positive benefits on increasing infiltration (>44), reducing runoff (>30%) and soil erosion (>33%) and increases soil biodiversity. This summary of key considerations for evaluating practices from multiple perspectives including provisioning, regulating, supporting and cultural ecosystem services is important to inform future soil health policy and research initiatives in SSA.

This study in China looked at temporal dynamics of SOC under NT with residue retention (RR) in a wheat-maize system. Their data shows that SOC can significantly increase to a depth of 30 cm with NT and RR. On average, NT increased SOC by 8.1–34.5% compared with CT, and RR increased SOC by 3.5–14.4% compared with R0 at 0–10 cm. Positive effects of NT and RR on SOC were both confirmed, but fluctuations and variations induced by interactions of practices and seasonal climatic conditions were also significant in the North China Plain

This paper looked at the effect of tillage, crop establishment and residue management on total and different pools of  SOC in a sandy-loam soil from a 6 year study in NW India. Treatments looked at CT against ZT with direct seeded and Transplanted rice followed by wheat with and without residues. The study showed that adoption of ZTDSR followed by ZTW + R was the better crop production strategy for increasing C-sequestration, improving and sustaining the soil quality and crop productivity in the RW system. This practice also provides an opportunity to retain crop residues as an alternative to burning, which causes severe air pollution in the RW system in the IGP of South Asia.

This study looked at changes in soil organic and inorganic (SOC and SIC) carbon under CA in Eastern India. The treatments included various combinations of CT and ZT rice and wheat with and without residue and on permanent beds (PB) with residue. The highest SOC at both 0-15 and 15-30 cm was with the ZT plus residue for both crops. The benefits of ZT and residue retention were greatest for very labile SOC, which showed a significant  increase (50%) under ZT-ZT+R compared with CT-CT. They conclude the adoption of CA should be recommended in calcareous soils, for C sequestration, and also as a reclamation technique. 

This study evaluated the level of tillage and quantity of soil cover for CA to work under irrigated conditions in the highlands of Mexico. Treatments included conventional tillage (CT), two types of reduced tillage, and permanent beds (PB) without tillage and 4 levels of soil cover in a maize, fodder oats rotation. Both crops yielded most under PBs without tillage and had the highest net returns. . 

Soil degradation by soil organic carbon loss is a major concern in SSA. This study assesses the long-term (13 years) changes in SOC, aggregate associated C, particulate organic C (POC) and infiltration in sub-tropical, monocropping maize at 3 soil depths in South Africa. Tillage treatments were No-till (NT) and rotational tillage (RT) both with permanent residue cover and CT with residue removed. Nitrogen treatments were 0, 100 and 200 kg/ha. On average Total SOC did not differ between tillage treatments, but varied with depth where it was stratified in the 0-10 cm depth in NT and RT. POC varied and decreased significantly in the 0-10 cm depth with increased tillage intensity. They conclude that reduced soil disturbance improves physical protection of SOC, soil structure and infiltration but TSOC takes time to improve.

This paper looks at the effect of CA and CT with cover crops (CC) on carbon sequestration in northeast Italy. They looked at SOC stock over a 6 year period within a 0-50cm soil profile. The results suggested that CA changed the SOC distribution rather than the total amount of SOC. Over a 6-year period, no benefit in SOC sequestration was observed with CA and CC. They hypothesize that a longer study period would be required to better understand the potential benefits of CA and CC on SOC sequestration. 

This paper used the ARMOSA process-based crop model to simulate the contribution of different CA components to soil organic carbon stocks sequestration at 0-30 cm depth compared to conventional in three different regions (Central Asia, N and S Europe). Simulations looked at current and future climate conditions.  Five cropping systems were used. The paper concludes the simultaneous adoption of all the three CA principles becomes more and more relevant in order to accomplish soil C sequestration as an urgent action to combat climate change and to ensure food security.

Data presented is from the 6th season of an on-station trial with CT and NT and 4 crop rotations that included maize, wheat and soybeans. The residues were left on the surface in NT and incorporated in the CT after every cropping season. Soil physical properties were measured. The study concluded that the crop rotations, MWM and the MWS under the no-till coupled with the residue retention improved the soil porosity and the soil water content levels the most. 

This study compared N2O emissions and crop yield of soybean under NT and CT using rye and hairy vetch residues from cover crops for 3 years in Italy. N2O emissions in NT were 40-55% lower compared to CT. NT also increased SOC content and earthworm abundance. Within NT systems rye had lower N2O emissions compared to hairy vetch as a consequence of the high C/N ratio of rye residues.

This study looked at conventional (CT) and No-till (NT) in wheat/maize following puddled  or non-puddled TP rice or direct seeded rice. Also residue removal or retention. They looked at soil aggregation, carbon pools, nutrient availability and yield. After 6 years in top 20 cm soil, NT treatments had had more total organic carbon than CT treatments. NT treatments also had more stable soil aggregates. Retention of residues increased TOC,  and soil available nutrients, especially P, K and Zinc over residue removal. The conclude that NT with residue retention should be recommended for improving soil quality and production sustainability.

This study in the Northern China Plain looked at 11 years of of six agricultural practices on soil organic carbon storage, crop yield and yield stability in a maize-wheat system. The three tillage systems were conventional (CT), No-till (NT) and sub-soiling (ST) with straw returned or removed. The highest SOC was in NT and ST with residue. Highest yields were with ST with and without straw return. NT, ST and straw return both increased crop yield stability. Maize and wheat yields were positively correlated with SOC storage.