The effect of Push-pull management and fertilization in central Kenya

The high population pressure in central Kenya has lead to continuous cultivation with minimal application of nutrient, resulting in nutrient depletion. A study was conducted to determine the effect of ‘Push-pull’ (intercropping maize with Desmodium and Napier grass) strategy management and nitrogen application on maize grain yield and soil fertility on smallholder farmer’s fields in three districts of central Kenya highlands. The experiment design was a split plot design with two factors (‘Push-pull’ vs monoculture and manure (5 t/ha) only vs manure and fertilizer (40 kg/ha) replicated four times.I found an increase in maize yield in ‘Push-pull’ fields compared with monocultures with only manure added (5t/ha) and the yield increased even more with modest application of fertilizer (40KgN/ha) combined with manure (5t/ha).There was strong significant difference (p<0.001) on maize grain yield between ‘Push-pull’ (5.52t/ha) and monoculture (1.93t/ha) cropping systems in the three districts of central Kenya.From management perspective, the different fertilization regimes had strongest positive effect on maize yield in well managed ‘Push-pull’ cropping systems.