Development and Dissemination of 4R Nutrient Stewardship Knowledge to Support Crop Production Intensification in Western Kenya

There is an urgent need for the sustainable intensification of crop productivity in smallholder farming systems, given the current low productivity levels which frequently fall short of meeting the food needs. The 4R Nutrient Stewardship principles provide a framework that help farmers have sustainable increases in their crop yields and profits. Results from a project over the past four years illustrate that this is feasible. In the past five years, IPNI has employed field and ICT-based approaches to disseminate 4R Nutrient Stewardship knowledge and practices in a pilot site in western Kenya, targeted at supporting crop production intensification among smallholder farmers. The project used on-farm demonstration sites to demonstrate the impact of various 4R techniques, including site- and crop-specific fertilizer recommendations, on crop productivity and profits. The project also developed various 4R knowledge products for farmers, extension agents and fertilizer dealers, while using various media and ICT platforms to communicate 4R information to farmers.

Analysis of yield data from nutrient omission sites demonstrated that improved crop yields can only be sustained through balanced nutrition. Mean maize grain yield in the nitrogen, phosphorus, and potassium (NPK) treatment was always >4 t/ha, and was consistently higher than all other treatments in all cropping seasons. Omission of any one of the macronutrients resulted in a steady decline in yields over time, whereas under full macronutrient application, yields remained relatively stable. Balanced nutrition with NPK was also observed to result in lower variability in yields compared to the other treatments.

The success of the dissemination strategy developed by the project offers a simplified step by step platform that can be used in successfully disseminating 4R nutrient management knowledge in other parts of the region, with the key objective of helping smallholder farmers sustainably increase yields and profits in their farms. However, for farmers to fully benefit from the 4R components, there is need for further interventions at the policy level aimed at improving the current extension agent: farmer ratio, reducing the farm gate prices of fertilizers to enable farmers afford fertilizers at the right quantities, and improved access to markets to allow farmers enjoy benefits of increased production, among other interventions.