Nitrogen fertilizer management for quality protein Maize using normalized difference vegetative index Sensor at bako, wetsern Ethiopia

Abstract

Crop production is a complex system that integrates physical, chemical and biological processes and is managed under increasing economic and ecological constraints. Maize is one of a high valued crop in Ethiopia, especially in western regions of the country where it is the dominant crop and is produced in a number of agro-ecologies in the region. Despite tremendous yield potential, its productivity is constrained by blanket application of inorganic nitrogen (N) fertilizers. This experiment was conducted during 2016 cropping season at Bako, western Ethiopia with the objectives of validating and determine the optimum nitrogen fertilizer rate for side dressing supported by normalized difference vegetative index (NDVI) sensor for quality protein maize for efficient management of N to optimize grain productivity of quality protein maize. The trials were laid out in a factorial randomized complete block design with three rates of nitrogen fertilizer (0, 25 and 50 kg N ha-1 ) applied at planting and four rates of estimated N (19, 38, 56 and 75 kg N ha-1 ) applied as side dressing. The mean yield components of quality protein maize variety were significantly affected by application of nitrogen rates. Significantly higher mean grain yield of quality protein maize was obtained between 63 kg ha-1 N (25 kg ha-1 at planting with 38 kg ha-1 side dressing) up to 100 kg ha-1 N. Significant differences were also observed on measured NDVI and In-season estimation of yield (INSEY) at node initiation (V4) growth stage of maize. Grain yield shows a higher correlation coefficients (0.78**) with NDIV and INSEY at V4 growth stage of maize. The NDVI reading and calculated INSEY at node elongation growth stage have strong correlation with grain yield (0.79** and 0.75**). Overall, application of 25 kg N ha-1 fertilizer rates at planting with 38 kg N ha-1 side dressing had better net benefit of ETB 53590 ha-1 . Therefore, application of 25 kg N ha-1 at planting with 38 kg N ha-1 for side dressing is recommended for quality protein maize variety in Bako area and similar agro-ecologies.