PLANTAS DE COBERTURA NA RENOVAÇÃO DA CANA-DE-AÇÚCAR - INFLUÊNCIA NO SOLO, ESTADO NUTRICIONAL E DESENVOLVIMENTO DA CANA

Abstract

In the renewal of sugarcane areas, excessive soil disturbance associated with the absence of vegetation cover has led to soil degradation. The use of cover crops prior to sugarcane implantation is a promising alternative to reduce this degradation, however, little is known about its effects on the soil, as well as sugarcane development and nutrition. The aim of this study was to evaluate the influence that the cultivation of pearl millet – Panissetum glaucum, crotalária – Crotalaria juncea and brachiaria – Brachiaria ruziziensis prior to sugarcane implantation has on the chemical and physical attributes of the soil in a sugarcane renewal area, as well as on the development and nutritional status of sugarcane. The cultivation of these species was efficient in improving the physical and chemical attributes of the soil up to 0.4 m depth, providing lower soil mechanical resistance to penetration, greater macroporosity, microporosity and total porosity. It also provided higher levels of Ca, Mg and potassium in the soil, especially millet, denoting its efficiency as a K recycler. As for the nutritional aspect and sugarcane development, it contributed to raise the phosphorus content, as well as of nitrogen (after millet) and sulphur, iron and manganese (after crotalária), resulting in the emission of more tillers.