Influence of Phosphorous and Nitrogen Fertilizer Rate on Grain Yield of Rice at Kamashi Zone of Benshal-gul Gumuz Region, Ethiopia

Abstract

The scientific information available with regards to the response of upland rice to N and P fertilizers for its optimum production on nitosols of Kamashi zone is very limited. Therefore, a field experiment was conducted on nitosols of Kamashi, western Ethiopia to study the yield and yield components response of rice and to establish the optimum N and P fertilizer levels required for improved grain yield of upland rice. Field experiments were conducted at Kamashi locations, for two years at this location, to investigate the response of rice N and P fertilization. Four levels of N (0, 46, 92, 138 kg ha-1) and four levels of P (0, 10, 20 and 30 kg ha-1) were studied in factorial combinations in a randomized complete block design with triplicates. The results revealed substantial responses of rice to the main factors of N and P fertilization on grain yield, No. of panicle/m2, No. of tiller/plant, No of tiller/m2, and plant height. Rice grain yield, No. of panicle/m2, No. of tiller/plant, No of tiller/m2, and plant height increased significantly with increasing level of P and N (P < 0.001). The effects of N by P interaction were non-significant (P ≤ 0.05) among the different yield and yield components studied except panicle length (p < 0.05) and straw yield (P < 0.01). Mean grain yield was significantly (P < 0.001) enhanced by 16.2% with the application of 10 kg P ha-1, 23.6% with application 20 kg P ha-1 and 34.6 with the application of 30 kg P ha-1 over zero-P (Table 2). High N at 138 kg ha-1 significantly (P < 0.001) increased the yield of rice by 47.2%, while 92 kg N ha-1 increased it by 36.2%, and 46 kg N ha-1 increased the yield by 32.5% compared to 0 kg N ha-1. There was no significant difference in grain yield between 46, 92 and 138 kg N ha-1. The magnitude of increase in grain yield over the control due to application of 46 N and 10 P ha-1 were 32.5% and 16.2% higher over the control respectively. The partial budget analysis also indicated economic benefit for finger millet when it is fertilized with 46 N and 10 P kg ha-1.