Shiferaw Nesgea, Heluf Gebrekidan, J. J. Sharma, Tareke Berhe
Gambella Regional Agricultural Research Institute, P.O.Box 62, Gambella, Ethiopia
Colleges of Agriculture and Environmental Sciences, Haramaya University, P. O. Box 138, Dire Dawa, Ehiopia.
Department of Plant Sciences, Haramaya University, P. O. Box 138, Dire Dawa, Ethiopia
SASAKAWA Africa Association`s, Regional Rice Program, Addis Ababa, Ethiopia
Key words: Application time, NERICA-3 rice, nitrogen sources, partial budget, yield, yield attributes.
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). Only grain and straw yield significantly (P ≤ 0.01) influenced by interaction of N sources and application time whereas the other yield and growth components and grain protein not (P > 0.05). Effects of sources of N, interactions of year by sources of N, year by application time and year by sources of N by application time were insignificant(P > 0.05) on the rice growth, yield components and grain protein. Significantly increased rice grain yield (6.33 t ha-1) obtained with NH4NO3 applied ½ at sowing + ½ at tillering. The, results were subjected to economic analysis using the partial budget procedure to determine sources of N and application time that would give acceptable returns to farmers. Economic analysis showed that CO(NH2)2 applied ½ at sowing + ½ at panicle initiation and ½ at tillering + ½ at panicle initiation are superior and stable within a price variability range of 15%. Hence, it may be recommended for production of NERICA-3 rice under the climatic conditions prevailing in the study area.
Get the original articles in Source: Volume 2, Number 9, September 2012 – IJAAR
Published By: International Network for Natural Sciences