Fertilizer application levels in potato crops and the diagnosis and recommendation integrated system (Dris)

Abstract

The rates of nitrogen, phosphorus, and potassium fertilizers used in the cultivation of potatoes are often considered excessive, as they can cause imbalance among the essential elements present in the soil. Using leaf nutrient analysis, this study aimed to evaluate the productivity of potato tubers subjected to different rates of nitrogen (N), phosphorus (P), and potassium (K) to establish the diagnosis and recommendation integrated system indices. Three experiments were conducted, one for each nutrient (N, P, and K), with Agata and Atlantic cultivars in Unaí (Minas Gerais state) and the Agata cultivar in Mucugê (Bahia state). The nutrient rates were 0, 30, 70, 120, and 280 kg ha−1 of N; 0, 150, 300, 600, and 900 kg ha−1 of P2O5; and 0, 70, 110, 220, and 450 kg ha−1 of K2O. Agata and Atlantic had adequate nutritional balance under K application. Agata had a more adequate nutritional balance under P application in Mucugê, whereas K fertilization was more decisive for the nutritional balance in Unaí. The differences in the results can be explained by the different soil textures and nutrients in the soil between the regions. The results show the need to consider the soil conditions and the nutrient uptake/translocation capacity of cultivars before establishing rates to increase production revenue and avoid the waste of fertilizers.