Soil Uses in the Sugarcane Fallow Period: Physical Oxisols Attributes, Sugarcane Productivity and Quality.

Crop diversification provides benefits to the soil aggregation and yield potential of the following sugarcane cycle. The objective of this study was to evaluate the physical attributes of two Oxisols, a very clayey eutroferric Oxisol (clay content = 680 g kg^-1) and a clayey acric Oxisol (clay content = 440 g kg^-1). The study took place in two experimental areas located at Brazil (21°14’05” S, 48°17’09” W). A randomized block design was used with four treatments and five replications. The treatments were different soil uses in the sugarcane fallow period: soybean/millet/soybean, soybean/sunnhemp/soybean, soybean/fallow/soybean, and soybean. Thirty months after the sugarcane fallow period, soil samples were collected at 0.00-0.10, 0.10-0.20, 0.20-0.40, and 0.40-0.60 m depth. In each soil sample were determined the attributes of the two Oxisols: organic matter content, water aggregate stability index, aggregate mean weight diameter, penetration resistance, bulk density, total porosity, macroporosity, and microporosity. The Oxisols attributes were not affected by the different soil uses. On eutroferric Oxisol was determined higher water aggregate stability index than this acric Oxisol attribute probably due to higher organic matter content. Consequently, the total porosity value was higher and bulk density value was lower on eutroferric Oxisol than on acric Oxisol. The macroporosity value was lower and the microporosity value was higher on eutroferric Oxisol than on acric Oxisol probably due to higher clay content. On third sugarcane harvesting, the productivity and technological parameters were not affected by different soil uses in the sugarcane fallow period. The results confirmed the influence of clay and organic matter content on Oxisols attributes.