Nutrient Management for Grain Legume Crop Production in Africa

IPNI-2012-GBL-49

29 Apr 2016

2015 Annual Interpretive Summary


The study was initiated in Muguga, Central Kenya in 2012 as part of the Global Maize network of trials to identify site-specific nutrient management practices that for sustainable intensification of maize production. The overall objective is to evaluate opportunities for Agroecological Intensification (AEI) as a means to improve maize yields at a faster rate than farmer practice, while minimizing adverse environmental effects. Mugaga is in a high potential maize production zone (av. Annual rainfall = 1,700 mm). The experimental treatments included: (i) current fertilizer recommendation (120 kg N/ha + 40 kg P/ha); (ii) AEI (120 kg N/ha + 40 kg P/ha + 40 kg K/ha + 16 kg S/ha + 35 kg Ca/ha + 15 kg Mg/ha + 5 kg Zn/ha + 5 kg B/ha; and (iii) 50% AEI consisting of half the fertilizer rate of the AEI treatment. The 50% AEI treatment was included as an option relevant for smallholder farmers who currently use very low rates of fertilizer. The trial has been implanted for three consecutive maize production seasons.

Maize yields achieved with fertilizer across all treatments were >6 t/ha, which is more that 600% higher than the current average maize yields in smallholder farming systems in sub-humid zones in central Kenya, indicating a large yield gap between current and attainable yields. The 2015 trial results showed that balanced nutrient management (N + P + K + S +Zn + B) resulted in an increase in average maize yields by about 5%, which was less than the 10 to 15% increase achieved in the previous three seasons. The results from the project have contributed to the by the Kenya Agricultural and Livestock Research Institute to revise fertilizer recommendations for maize production in Central Kenya.