Effect of the Rate of N-fertilizer Application on Growth and Yield of Wheat (Triticum aestivum L.) at Gamo-gofa Zone, Southern Ethiopia

Abstract

There is little knowledge among farmers on the rate of N-fertilizer application at Gamo-gofa. Therefore, there is a need to determine rate of N-fertilizer application on growth and yield of wheat. Accordingly, an experiment were conducted to evaluate the effect of the rate of N-fertilizer application on yield and yield components of wheat on two locations at Gamo-gofa, Southern Ethiopia in 2014 and 2015 cropping season. A factorial combination of the rate (0, 23, 46, 69 and 92 k.gha^-1) of N-fertilizer application was arranged in split plot. Rate of N-fertilizer had significantly affected days to heading, plant height, number of tiller, panicle, grain, straw and total biomass yields. Also year and location had significantly affected maturity and spike length. Fertilizer applied 92 kg ha^-1 minimize the date of heading by eight days compared with control. Wheat planted in 2014 was delayed the date of maturity by twenty days compared with planted in 2015. Fertilizer applied 23 kg ha^-1 had contributed for 10.5 cm increments in height than control and N applied 46 kg ha^-1. Fertilizer applied with the rate of 92 kg ha^-1 was contributed 5.0 cm increment in spike length than control. Fertilizer applied 92 kg ha^-1 had 28.6 % more tillers than control, but 58.8 % less tillers than fertilizer applied 69 kg ha^-1. Fertilizer applied 69 kg ha^-1 contributed to 33.6 % increment in biomass than fertilizer applied 23 kg ha^-1. Fertilizer applied 23 kg ha^-1 had 37.3 % less straw than fertilizer applied at the rate of 69 kg ha^-1. Fertilized applied at fifteen  days after planting with rate of 23 kg ha^-1had  25.5  % more grain yield than control. Wheat planted in 2015 had 35.7 % less harvest index than which, planted in 2015. Thus, N fertilizer applied at the rate of 69 kg ha^-1 is economically beneficial compared to the other treatments.

Keywords: Rate of fertilizer, Fertilizer, Nitrogen