Aplicação de doses elevadas de vinhaça em um argissolo cultivado com cana-de-açúcar

Abstract

The stillage is a sub product of sugar and alcohol industry, has high importance to plant mineral nutrition mostly because of organic matter and minerals that are present, however, the lack of appropriate management of the dose can reflect problems to soil sugarcane development. The goal of this study is evaluate the effect of high stillage doses on sugarcane initial development, change in chemical attributes and soil salinization. The experiment occurred in a greenhouse, the sugarcane was cultivated in vase filled with Ultisol during 210 days of cultivation. The treatments were: mineral nutrition (MN), 0 (D0), 150 (D150), 300 (D300), 600 (D600) and 1200 (D1200) m3 ha-1 of stillage. The mineral nutrition treatment received the formula NPK 14-24-18 and D0 received only water. The plots were organized randomly in the greenhouse containing 6 treatments and 30 repetitions. The stillage’s effect was studied relating the dosages and the time of cultivating. Were analyzed biometric parameters, plant nutrition, chemical soil attributes and salinization. It was noted that the highest doses, D600 e D1200, were responsible for the increase in leaf area index, fresh biomass and dry biomass of the stem, the root and the top plus leaves. In the mineral nutrition of sugarcane, the potassium (K) contents was higher than recommended to the growing stage analyzed, the calcium (Ca), magnesium (Mg) and sodium (Na) were lower, thus inferring that the plant presented preference for absorbing K instead Ca, Mg and Na. On the soil, was observed increase the amount of organic matter, pH, Ca, K and Na, mostly at the doses D600 and D1200. The K and Na change their concentration on soil according to the time measured, the cations has presented more availability on soil solution around 120 days. The stillage application increased the electrical conductivity and percentage of exchangeable sodium. The application of 600 e 1200 m3 ha-1 stillage doses modify the sugarcane growing and soil fertility.