EFFECTS OF BLENDED NPS FERTILIZER SUPPLEMENTED WITH NITROGEN ON YIELD AND YIELD COMPONENTS OF MAIZE (ZEA MAYS L.) AT DILLA, SOUTHERN ETHIOPIA

Abstract

Maize is one of the most important cereal crops in Ethiopia. However, the yield of the crop is low mainly due to low soil fertility problems. Therefore, this study was conducted to identify the effect of blended NPS fertilizer supplemented with inorganic N and to estimate the economically feasible fertilizer rate for higher yield of maize. The experiment consisted of four levels of NPS fertilizer (0, 50, 100 and 150 kg ha-1) each supplemented with four levels of N (0, 32, 64 and 96 kg N ha-1) and control. Randomized Complete Block Design in factorial arrangement with three replication was used. The results showed that the plant height, leaf area, leaf area index ,days to physiological maturity ,no of grain per cob, no of grain per row, no of ear per plant and grain yield were significantly affected by main effect of blended NPS and Nitrogen. The tallest (205.5cm) plant height was obtained from 150 kg blended NPS ha-1treated. The interaction of blended NPS with nitrogen rate had significant effect on all parameters, except. Plant height, leaf are, leaf area index, days to physiological maturity, no of grain per cob, no of grain per row , no of ear per plant and grain yield .The highest thousand kernel weight (345.3 kg ha-1), highest no of row per cob (14.0) and highest harvest index (51.4%) were obtained from application of 150 kg NPS ha-1 with 96 kg of N ha-1. The results of the economic analysis showed the maximum net return (1445.0%) was under the application of 100 kg NPS ha-1 + 96 kgN ha-1. In conclusion, the results of the study showed that application of 100 kg blended NPS ha- 1 supplemented with 96 kg N ha-1 enhanced yield of maize with acceptable economic benefit. However, the experiment was carried out only in one location for one cropping season, further studies at different locations for several years or seasons should be conducted in the study area and economically feasible levels of blended NPS and N fertilization should be analyzed.