Enhancing the Capacity for Dissemination of Site-specific Maize Production Intensification Technologies under Variable Farm, Climatic and Soil Fertility Conditions in Kenya and Zimbabwe

Maize is the most important food crop in Kenya and many other countries in Africa. However, its productivity has remained low mainly due to climatic conditions and soil constraints. Conservation agriculture (CA) based on reduced tillage, surface retention of crop residues, and crop rotation can help in the amelioration of these constraints. An experiment was initiated in 2014 to evaluate the long-term effects of balanced nutrient management in maize production systems under CA and conventional tillage (CT).

A fertilized maize crop was planted during the long rainy season and then was rotated with an un-fertilized bean crop during the short rainy season. The bean crop is expected to benefit from the residual fertilizer from the maize planted in the previous season. The fertilizer treatments were nitrogen and potassium (NK), nitrogen and phosphorus (NP), PK, NPK, and NPK+calcium (Ca)+magnesium (Mg) +zinc (Zn) +boron (B) +sulfur (S). The project is implemented in collaboration with the International Maize and Wheat Improvement Center (CIMMYT), Kenya Agricultural and Livestock Research Organization (KALRO), and the University of Nairobi.

Key findings from the long-term balanced nutrient trials over the past year indicate that CA increased maize grain yields relative to CT by 36%. Additionally, balanced nutrition (NPK+Ca/Mg/Zn/B/S) had the highest grain yield across both CA and CT. The results highlight the importance of balanced nutrient management and CA for sustainable maize production intensification in Kenya. Similarly, CA increased the unfertilized bean yields relative to CT by 38%.

In terms of capacity building, an M.Sc. student from the University of Nairobi conducting research on the project was able to complete his thesis titled “Nutrient management options for enhancing productivity of maize and bean under conservation and conventional tillage systems.”