The best nutritional practices aim to increase nutrient use efficiency in order to reduce production costs and environmental impacts. In order to evaluate nitrogen and potassium use efficiency in banana crops, two field experiments were carried out during four cycles of production. The experiments were cropped with Giant Cavendish banana (Musa AAA, Cavendish subgroup) in Planalto Region of State of Sao Paulo (Brazil). This region is characterized by a summer rainy season and dry winter. In the first experiment, the efficiency of the rates of N (0, 200, 400 and 800 kg ha-1) and K (0, 300, 600 and 900 kg ha-1 of K2O) were compared in banana grown in irrigated and non-irrigated plots. In the second experiment, was compared N and K fertilizer efficiency applied through fertigation and conventional solid fertilization. In both experiments, irrigation and fertigation were made by micro-sprinkler and employed ammonium nitrate and potassium chloride as a source of N and K, respectively. The fertilizer efficiency was estimated by the ratio of the mass of fruit produced per unit of applied nutrient. The results of polled harvest have shown that irrigation increased the nutrient use efficiency compared to non-irrigated, for the averaged nutrient rates, close to 36 % and 32 % for N and K, respectively. Fertigation promoted an increase of 36 % in nutrient use efficiency compared to conventional fertilization, for either nitrogen or potassium. Increases in nutrient use efficiency contributed to reduce fertilization costs.
nutrient use efficiency; nitrogen; potassium; banana
