Sensor based validation of nitrogen fertilizer for quality protein maize variety using a handheld normalized difference vegetative index sensor at Bako, Western Ethiopia

Regardless of the huge yield potential and area under maize production, its current productivity in Ethiopia is by far below its potential. Declining of soil fertility and poor nutrient management is among the major factors limiting the productivity of the crop. As a result, an experiment was conducted at Bako, Ethiopia in 2016 to validate the N application and determine the best rate for side dressing using handheld Normalized Difference Vegetative Index (NDVI) sensor. The experiment was laid out in randomized complete block design in factorial arrangement with three replications. Three N levels (0, 25 and 50 kg N ha-1) all applied at the time planting and four N rates (19, 38, 56 and 75 kg N ha-1) for side dressing. Significant differences were observed between the applied N fertilizer for grain yield and yield components. Higher correlation coefficients (0.78) between grain yield, NDIV and INSEY at V4 were observed. Application of 25 kg N ha-1 and 38 kg N ha-1 at planting and side dressing at 35 days after sowing correspondingly, gave higher grain yield for quality protein maize in the area. Further studies are required across various locations using different maize varieties to provide conclusive recommendations.   Key words: INSEY, maize, NDVI, nitrogen.