Response of maize (Zea mays L.) to rates of nitrogen and zinc application in Minna, Southern Guinea Savanna of Nigeria

Abstract

A field experiment was conducted in 2014 and 2015 cropping seasons at the Teaching and Research Farm of the Federal University of Technology, Minna to evaluate the effects of different rates of nitrogen (N) and zinc (Zn) on the growth and yield of maize. The treatments included four levels of N: 0, 60, 90 and 120 kg ha -1 and three levels of Zn: 0, 2.5 and 5 kg ha -1 . The experimental design was a 4 × 3 factorial design fitted in a randomized complete block design with three replications. The soil was relatively low in initial N content and relatively high in soil extractable Zn of 2.30 mg kg -1 . The main effect of N on the plant height of maize was significant (p<0.05) only at 8 weeks after sowing (WAS) in 2014 and 8 and 12 WAS in 2015. In 2014, the interaction effect of N and Zn on the plant height of maize was only significant (p<0.05) at 8 WAS in both seasons, and application of nitrogen rate of 90 kg N ha -1 with 5 kg Zn ha -1 produced the highest plant height at 8 WAS. The treatments without N produced the lowest grain and stover yields. There was a significant (p<0.05) response to N fertilization on grain yield in both seasons. The main effects of Zn on both stover and grain yields were only significant in 2015. The nitrogen rate of 60 kg N ha -1 with 2.5 kg Zn ha -1 was optimum for maize production in Minna, Nigeria.