Yield Related Traits and Yield of Quality Protein Maize (Zea mays L.) affected by Nitrogen Levels to achieve maximum yield in the Central Rift Valley of Ethiopia

Abstract

Maize is one of highly valued crop in the national diet of Ethiopians especially in southern and south eastern regions of the country; it is produced across various agro-ecologies of the country. However, its productivity is constrained by blanket application of mineral nutrients, in particular nitrogen (N). In this study, we aimed to test site-specific nutrient management particularly nitrogen to maximize yield, increase net benefit and reduce environmental pollution. Drastic increase in N fertilizer cost, environmental pollution and increased public scrutiny have encouraged development and implementation of improved N management practices. In this context, on-farm and on-station experiments were carried out during 2014 main cropping season in the central rift valley of Ethiopia. The experiment were layout using randomized complete block design (RCBD) with three replication having six treatments of nitrogen fertilizer, phosphorous fertilizer were applied uniformly to all treatments. Plant height, number of grains per ear, leaf area, leaf area index, grain yield, above ground biomass stover yield,1000 kernels weight  harvest index,  were significantly (P<0.05) affected by N fertilizer rate. However, seed nitrogen content was not affected by rate of N-fertilizer. Generally, 75kg ha^-1 N fertilizer have improved most of the yield related traits and yield of maize while 100kg ha ^-1 treatment  have improved only some of yield traits at both location . Hence, this is one  cropping season experiment has to be conducted through a different  seasons and locations of uniform agro-ecology, soil type and crop in order to made concrete conclusions and seat out site specific recommendations.

Keywords: maximum yield, nitrogen, quality protein maize, yield related trait.