Article,
Effects of nitrogen sources and application time on yield attributes, yield and grain protein of rain-fed NERICA-3 rice in Gambella, Ethiopia
International Journal of Agronomy and Agricultural Research (IJAAR), Vol. 2 (No. 9): p. 14-32 (October 2012)
Abstract
A field experiment was carried out under rain-fed conditions at Imla, Gambella Agricultural Research Institute in 2008 and 2009 main cropping seasons in order to compare the effects of N sources ammonium nitrate (NH4NO3), ammonium sulfate ((NH4)2SO4) and urea (CO(NH2)2) and their time of application (½ at sowing + ½ at tillering; ⅓ at sowing + ⅓ at tillering + ⅓ at panicle initiation; ½ at sowing + ½ at panicle initiation, and ½ at tillering + ½ at panicle initiation) on growth, yield attributes and yield of rice (Oryza sativa L.) variety NERICA-3 (O. sativa x O. glaberrima), in a factorial experiment laid out in a RCBD replicated thrice. Nitrogen from each source was applied at the rate of 92 kg N ha-1, and the plots received uniform dose of 46 kg P and 20 kg K ha-1 at sowing. The results revealed that effects of year on rice days to flowering, panicle length, number of grains and grain weight panicle-1, grain yield, grain protein content (P ≤ 0.01), plant height, and straw yield (P ≤ 0.05) were only significant. The responses of rice growth and yield components and grain protein to sources of N were not significant (P > 0.05). Plant height, panicle length and grain weight panicle-1 to application time were significant (P ≤ 0.05) while the other growth and yield components and grain protein were not (P > 0.05).
