Soil Moisture Retention Through Crop Rotation and Organic Fertilizer Application as a Climate Adaptation Mechanism in Rainfed Agriculture of Ethiopia

When the rains stop in Ethiopia, smallholder farmers have almost no fallback. Irrigation is either unavailable or unaffordable, leaving crops exposed to dry spells at the most critical moments of growth. A new study by CIMMYT and Ambo University researchers, published in the Journal of Environmental Management, tested whether two simple agronomic practices, crop rotation and organic fertilizer application, could help soils hold onto moisture longer after rainfall ends. Over two consecutive seasons at a field site in West Shewa, Ethiopia, the team measured soil water content every two days following the last rainfall, tracking how different management choices affected the soil’s ability to buffer crops against drought stress.

The results were clear. Poultry manure conserved 20–30% more soil moisture than chemical fertilizer alone during dry periods, while legume-based crop rotations, particularly legume–legume sequences, retained significantly more water than cereal-only schemes. Maize planted after soybean showed the highest soil water content of any rotation tested. The findings point to practical, low-cost adaptation strategies that work within the realities of smallholder farming: no new infrastructure, no expensive inputs, just smarter choices about what to grow and how to feed the soil.