Author(s): Getahun Dereje, Bogale Walelign, Assefa Giddisa, Hailemariam Solomon, Afwork Hagos, Alemu Dabi, Regassa Dibaba and Dereje Alemu
Declining soil fertility is one of the major problems causing yield reduction of rice in Benishangul Gumuz Regional state. Therefore, field experiments were carried out at Bambasi District Assosa Zone, to evaluate and determine the effects of N and P fertilizer rate application on growth, yield and yield components of upland rice. The fertilizer treatments considered in the study was consist of four levels of N (0, 46, 92 and 138 kg N ha-1) and four levels of P (0, 23, 46, and 69 kg P2O5 ha-1). The experiment was laid out in a randomized complete block design (RCBD) with three replications at Sonka FTC and on three farmers fields consisting of a total of 16 treatments (mother trial). The results of the study revealed that most of yield and yield components of rice were significantly (P<0.05) affected by the main effect of N on mother and baby trails. Except grain per panicle, straw and grain yield; other parameters are not affected by the main effect of P fertilizer rate application. The highest grain yield (3244 kg ha-1) was recorded from 92 kg N ha-1 combined with 46 kg P2O5 ha-1 and the lowest grain yield (1415.6 kg ha-1) was recorded from the control treatment. Partial budget analysis also indicated that the highest net return (28548 Birr ha-1) was obtained from the application of 92 kg N ha-1 combined with 46 kg P2O5 ha-1 fertilizer rate. Thus, from the result of this study, it can be concluded that the application of 92 kg N ha-1 combined with 46 kg P2O5 ha-1 was found to be superior both agronomically and economically for rice NERICA-4 variety under main cropping season in the study area.
