Spatial variability of soil physical attributes under conservation management systems for sugarcane cultivation

Abstract

Conservation systems for soil management are increasing for sugarcane cultivation. However, there is still little information about the effects of this management on soil physical quality at different scales, fundamental to agricultural activity sustainability. The objective was to evaluate the variability and spatial dependence of Oxisol physical attributes under no-tillage and reduced-tillage in sugarcane cultivation. Undeformed soil samples were collected 45 days after sugarcane planting, using a regular mesh with intervals of 7.5 m, totaling 32 points in each tillage system. Soil density, resistance to penetration, total porosity, macroporosity, and microporosity were determined in two depths (0-0.10 and 0.10-0.20 m). Using geostatistical methods was verified in both tillage systems that spatial dependence in the two depths, prevailing in the layer 0.00-0.10 m, in no-tillage, strong dependence with the adjusted spherical model reduced preparation, moderate dependence, with exponential adjustment. In the 0.10-0.20 m layer, spatial dependence was an inversion and adjusted model, i.e., in no-tillage, there was moderate dependence, exponential adjustment, reduced preparation, strong dependence, and spherical adjustment. Linear correlations demonstrate how much soil physical attributes are related to management conditions and present behaviors like isoline cartogram.