Nutrient content and accumulation in sugarcane under mineral fertilization and high doses of vinasse

Abstract

Vinasse, a waste from ethanol production, has been widely used as a means of fertigation in sugarcane. However, high dose limits application at and its effects on nutrient absorption and accumulation by the crop are not known. The aim of this study was to evaluate and compare, during the initial development of sugarcane, the effect of mineral fertilization and high doses of vinasse on the macronutrient and sodium contents of the top visible dewlap (TVD) leaf and their respective accumulations in the aerial part of the crop. The experiment was carried out in 100-dm3 pots filled with Argisol. The treatments consisted of five doses of vinasse (0, 150, 300, 600 and 1200 m3 ha-1) and an additional treatment with no vinasse and mineral fertilizer (500 kg ha-1 of the NPK 14-24-18 formulation). The levels of nitrogen, phosphorus, potassium, calcium, magnesium and sodium were evaluated in the TVD leaf at 120 days after planting and their accumulation in the aerial part of the plant at 210 days. Data were subjected to analysis of variance and compared using regression analysis and orthogonal contrasts. The vinasse doses applied did not adequately nourish the crop in macronutrients. Mineral fertilization provided higher N and P levels. The highest doses of vinasse provided higher levels of K, Ca and Mg and larger accumulations of N, P, K and Na, but were detrimental to the accumulation of Ca. The descending order of accumulation of macronutrients and sodium with mineral fertilization was P> Ca> N> K> Mg> Na. For the application of vinasse, the descending order was K> P> Ca> N> Na> Mg. In the absence of mineral fertilization and vinasse, the descending order was P> Ca> K> N> Mg> Na.