Nitrogen Use Efficiency in Maize Hybrids (Zea Mays L.) at Different Nitrogen Application Rates in Eastern Part of Kenya

Abstract

IX ABSTRACT Nitrogen deficiency in soils prevailing in dryland region is one of the major factors contributing to poor yield in maize (Zea mays L.) production. It is therefore important to consider both ecological potential of maize hybrids and their nitrogen use efficiency (NUE) to improve on yield. The objective of this study was to determine physiological plant parameters of 6 maize hybrids that contribute to NUE in dryland areas. Six maize hybrids were evaluated at Kiboko research station in eastern Kenya. A randomized complete block design experiment was used at an equivalent nitrogen (N) application rates of 0 kg Nha-1, 40 kg Nha-1, 80 kg Nha-1 and 160 kg Nha-1. Results show chlorophyll was the key physiological parameter that had a positive impact (r2 =0.77) on NUE and GY. Grain yield of 397.56 g/1000 kernels was positively correlated with protein content in the grain r2=0.71, and a negative correlated with starch content (r2= -0.75). The findings infer that increasing N for hybrid 6 from 40 kg N/ha to 80 Kg N/ha increased yield by 5.22% whereas increasing N from 80 Kg N to 160 Kg N /ha resulted to an increased in grain yield by 1.59%.