Long-Term Trial of Tillage Systems for Sugarcane: Effect on Topsoil Hydrophysical Attributes

Seeking to provide essential information about sustainable tillage systems, this work aimed to assess the effects of liming and soil cultivation systems on the soil hydrophysical attributes of a long-term cultivated sugarcane field in the tropical region of southeast Brazil. Infiltration tests and soil sampling down to 0.10 m were performed in order to determine saturated soil hydraulic conductivity, soil bulk density, soil total porosity, macroporosity, microporosity, and soil resistance to penetration. The studied areas include no-tillage (NT) and conventional tillage (CT) systems with 0 (CT0 and NT0) and 4 (CT4 and NT4) Mg ha(-1) of lime, and an adjoining area with native forest (NF). The data analysis included an analysis of variance followed by the Tukey test to compare different systems, assessment of the Pearson correlation coefficient between variables, and a principal component analysis of the dataset. The lowest bulk density and highest soil total porosity, macroporosity and saturated hydraulic conductivity were found in the NF. The bulk density in CT4 and NT0 was higher than in other systems, indicating the need for amelioration. NT4 is suggested as the most viable system for conservation agriculture in sugarcane fields, combining the benefits of no-tillage and liming to enhance soil hydrophysical functions. (AU)