Carolina Fernandes, Soil Science, Sao Paulo State University, Jaboticabal, SP, BRAZIL and Roniram Pereira Silva, Soil Science, São Paulo State University, Jaboticabal, Brazil
Crop diversification during the sugarcane fallow period can improve physical soil attributes, increasing the yield potential of the following sugarcane cycle. The objective of this study was to evaluate the influence of different soil uses during the sugarcane fallow period before next sugarcane cycle, on the physical Oxisols attributes. The study took place in two experimental areas located at Brazil (21°14’05” S, 48°17’09” W), under two Oxisols: a very clayey (680 g kg-1) eutroferric Oxisol, and a clayey (440 g kg-1) acric Oxisol. 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. After first sugarcane harvesting, soil samples were collected at 0.00-0.10 and 0.10-0.20 m depth. In each soil sample were determined water aggregate stability index, aggregate mean weight diameter, bulk density, total porosity, macroporosity, and microporosity. The soil use soybean/millet/soybean under the eutroferric Oxisol promoted at 0.00-0.10 m depth lower bulk density due to higher total porosity. The soil use soybean/millet/soybean under the acric Oxisol promoted at 0.00-0.10 m depth higher aggregate mean weight diameter, and at 0.10-0.20 m depth higher water aggregate stability index, probably due to millet root system. On eutroferric Oxisol observed higher water aggregate stability index values probably due to higher organic matter values, and lower bulk density values probably due to higher clay contents. The results showed that the use soybean/millet/soybean during the sugarcane fallow period promoted better physical Oxisols quality.