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International Journal of Agronomy
Volume 2017, Article ID 1545280, 10 pages
Research Article

Effects of Nitrogen Rates and Time of Application on Yield of Maize: Rainfall Variability Influenced Time of N Application

Bako Agricultural Research Center, P.O. Box 03, West Shoa, Ethiopia

Correspondence should be addressed to Zerihun Abebe; moc.liamg@eeritaab

Received 14 February 2017; Revised 4 May 2017; Accepted 15 May 2017; Published 18 June 2017

Academic Editor: Manuel Tejada

Copyright © 2017 Zerihun Abebe and Hailu Feyisa. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Despite the fact that maize productivity is relatively better than other major cereal crops, its current productivity is still far below its potential productivity. N rate and time of application are among the major abiotic factors limiting the productivity of the crop. Because of such gaps, the experiment was conducted at Bako Agricultural Research Center in 2013 and 2014 cropping seasons to determine optimum N rate and time of application. Four levels of N rates (46, 69, 92, and 115 N kg ha−1) and four levels (, , , and ) of different time of N application were arranged in factorial combinations. Moreover, previously recommended N and the control were arranged in a randomized complete block design with three replications. In 2013, the highest significant biomass yield (21.2 tha−1) was obtained at 115 N kg ha−1 and followed by 69 N kg ha−1 at and and 92 N kg ha−1 at . In contrast, the highest grain yield in 2013 was obtained at 92 N kg ha−1 at followed by 115 N kg ha−1 at either or and 69 N kg ha−1 at either or application time. Interestingly, a significant yield increase by 37% was obtained when 92 N kg ha−1 at the time of was applied compared to previous recommended 110 N kg ha−1 rate and time of application. In 2014, however, the highest yield was recorded when 92 N kg ha−1 at was used. Application of 46 N kg ha−1 at showed statistically similar yield performance when compared with previous N recommendation. The lowest yield was recorded from the control plot in both years. In 2013, the maximum net profit and acceptable marginal rate of return (MMR) were obtained when 92 N kg ha−1 at was used for maize production during erratic and heavy rainfall distribution, particularly at a time of N application. However, the maximum net benefit (30743 ETB ha−1) and acceptable MRR could be obtained when 92 N kg ha−1 at was used if the rainfall amount and distribution are relatively uniform. In conclusion, application of 92 N kg ha−1 at (10–15 DAP and 35–40 DAP) is the best N rate and time of application in good rainy seasons and hence recommended for the end users. However, in the case of erratic and heavy rainy seasons, application of 92 N kg ha−1 at three times application regimes (1/3 N at 10–15 days after planting (DAP), 1/3 N at 35–40 DAP and 55–60 DAP) should be used to get maximum profit and acceptable MRR.