Conservation Agriculture Research Updates - March 2026

This paper presents results from a study done in the sub-humid and semi-arid location of Kenya, focusing on the effects of CA- and/or ISFM-based practices on maize yield on farmer fields.  Maize grain yield increase compared to the control was highest under ISFM in the low fertility fields in both locations and all seasons. The higher SWC observed under NTR and NTRM was related to no tillage with residue retention while under CTM it was related to improved soil organic matter through manure addition. The high NUE under CA was attributed to the placement of urea in the planting holes while maintaining residue on the soil surface. The low NUE under NTRM was linked to fertilizer N immobilization. Lastly, from the biomass yield, our study showed that monocrop maize under NTR requires a kick-starting by an ISFM-based practice in the low fertility fields of the semi-arid region.

The effects of contrasted cropping systems have been studied on upland rice yield and N uptake in rainfed conditions: conventional tillage (CT) and CA with a mulch of maize or a legume (Stylosanthes or velvet bean). This study used the "Decision Support Systems for Agrotechnology Transfer" (DSSAT) crop growth model to quantify the soil N balance according to the season and the cropping system in rainfed, upland rice in the hillsides of the Malagasy highlands. The model gave interesting results but the challenge is now to evaluate the model in less contrasted experimental conditions in order to validate its use for N uptake and yield prediction in support to the optimization and design of new cropping systems.