Alteration of the organic matter fractions in soil cultivated with sugarcane in the Cerrado-Amazon transition zone

The use of agroindustrial wastes, such as vinasse, may alter the soil chemical and physical characteristics. This study aimed to evaluate the total organic carbon and total nitrogen in a soil and the distribution of carbon and nitrogen in the sand and clay granulometric fractions, in three management systems (with and without vinasse application and with burning for harvest, in comparison with primary/native forest coverage), regarding fertilization and harvesting of sugarcane, in the Midwest region of Brazil. The use of organic wastes in the sugarcane production system may promote, even in a short time frame, conservation and improvement of the soil quality by the addition and maintenance of organic carbon. The use of vinasse favors the increase of the total organic carbon and total nitrogen in the soil, in the clay fraction, at all evaluated depths. The system with burning results in lower total carbon levels in the sand fraction, in comparison with the clay fraction, and, even with the sugarcane harvest employing burning, the most recalcitrant organic matter is associated with the clay fraction.