Smallholder crop-livestock farms in sub-Saharan Africa are confronted with limited access to plant nutrients, particularly synthetic fertilizers. The low use of synthetic fertilizers is attributed to financial constraints, which are exacerbated by current global events like the Ukraine war and volatile energy prices, and jeopardize food security and nutrition in Low-and-Middle Income Countries (LMIC). As a consequence, organic alternatives for plant nutrients, specifically livestock manures, are critically needed to enhance crop yields and improve soil fertility. However, inadequate manure management poses risks, including nutrient losses, environmental pollution, and health issues. By combining laboratory research with participatory field studies, this project will generate practical, evidence-based solutions for safe and sustainable manure management, improving agricultural productivity and environmental outcomes across East Africa.