Effect of starter nitrogen and phosphorus fertilizer rates on yield and yield components, grain protein content of groundnut ( L.) and residual soil nitrogen content in a semiarid north Ethiopia.

Increasing costs of chemical fertilizers, environmental concerns of their application and demand for protein foods, placed an extensive interest in growing of legume crops for human nutrition, and soil fertility replenishment. This study was conducted to investigate the effects of nitrogen (N) and phosphorus (P) fertilizers on parameters of phenology, growth performance, grain yield, yield components, grain protein content of groundnut, and residual soil nitrogen content in the northern Ethiopia during the growing season of 2017. Three levels of N (0, 15 and 30 kg ha) and four levels of PO (0, 23, 46 and 69 kg ha) were set in factorial combinations of randomized complete block design with three replications.