Agronomic and Economic Performance of Potato (Solanum tuberosum L.) in Response to Nitrogen and Phosphorous supply at Bekoji, Southeastern Ethiopia

An experiment was conducted at Bekoji in southeastern Ethiopia during the 2021 and 2022 cropping seasons to evaluate different N and P fertilizer rates on agronomic performance, tuber yield, and economic profitability of potato tuber production. The treatments used consisted of four levels of nitrogen (0, 46, 92, and 138 kg ha-1) and phosphorus (0, 46, 69, and 92 kg ha-1) combined with factorial arrangements and laid out in a randomized complete block design with three replications. The results revealed that almost all parameters were significantly affected by the main effect of nitrogen and phosphorus fertilizer rates, still their interaction did not affect yield except potato plant height. As a result, in both seasons, the highest total tuber yield was obtained at the combined application of 138 kg N with 92 kg P2O5 ha-1. However, the partial budget analysis indicated that the combined application of 92 kg N and 92 kg P2O5 ha-1 gave the highest net benefit with an acceptable marginal rate of return (MRR) of 644.68%, which might be taken as a profitable rate for the test area. Therefore, based on economic performance, it can be concluded that the fertilizer application at the rate of 92 kg N ha−1 in combination with 92 kg P2O5 ha−1 fertilizer rates is more economical and hence, recommended for potato production in the study area.