Growth and Yield Responses of Maize (Zea Mays L.) to Different Nitrogen Rates under Rain-Fed Condition in Dilla Area, Southern Ethiopia

Abstract

Efficient use of N fertilizer for maize (Zea mays L.) production is important for maximizing economic return and minimizing NO₃ leaching and/or environmental pollution. A field experiment was conducted at the research site of Dilla University (Ethiopia) during the 2014 cropping season, to determine the effect of different levels of N on growth and yield attributes of maize. A well-adapted maize variety, Pioneer, was tested at four different N rates: 0, 23, 46 and 69 kg N ha^-1. The number of leaves plant^-1, plant height, cob length, total biomass and grain yield were significantly (p < 0.05) influenced by varying N levels. Among N levels, the highest mean grain yield (8.62 t ha^-1) was obtained by an application of 69 kg N ha^-1. There were 13.9%, 22.4% and 30.8% increases in grain yield from the application of 23, 46 and 69 kg N ha^-1, respectively, over the control. Maximum plant height (2.97 m), and total biomass (16.72 t ha^-1) were obtained by an application of 69 kg N ha^-1, whereas maximum cob length (36.3 cm) and yield component (3.39 t ha^-1) were recorded from 46 kg N ha^-1. Based on the results, it was concluded that application of N at 69 kg ha^-1 can be recommended for achieving optimum grain yield under sub-humid environment of Dilla area.

Keywords: Growth, Grain yield, Maize, Nitrogen