Impact of Sugarcane Reform System in Sandy Soils on Organic Carbon and Soil Chemical Attributes

The demand for biofuels has led the Brazilian sugar-energy sector to advance in areas with sandy soils poor in organic matter and fertility. The objective of this study was to analyze the effects of different sugarcane culture reform systems on the fraction organic and chemical attributes of a sandy Ultisol. Three treatments of sugarcane reform systems (Conventional, Conventional + Soybean and Conventional + Crotalaria cover) were selected for the study. We collected 40 samples in the 0–10 cm layer to determine the organic carbon by the Walkley–Black methodology and chemical attributes pH; H + Al; Al 3+ ; levels of Ca 2+ , Mg 2+ , K + ; CEC; BS%; P P; ∆pH and ZPC. The sugarcane reforming systems did not affect Al 3+ , H + Al, Mg 2+ and BS%, but did affect pH, CEC, Ca 2+ , K + and P. There was no correlation between OC and Al 3+ , Ca 2+ , Mg 2+ and BS%, but there was between OC and ∆pH and ZPC. The results indicated that the conventional management + coverage of Crotalaria presented the highest amount of OC, the highest values of Ca 2+ , K + , CEC and productivity of sugarcane stalks/ha, and the lowest pH. Al 3+ , H + Al, Mg 2+ and BS% were not affected by the studied management. As for the available P, the conventional tillage and conventional tillage + soybean management presented equal and higher levels than the conventional tillage + Crotalaria cover systems but presented stalk productivity/ha lower than the latter.