SPATIAL VARIABILITY OF THE GRANULOMETRIC FRACTIONS AND CHEMICAL ATTRIBUTES OF A SANDY SOIL UNDER A NO-TILLAGE SYSTEM

Abstract

: The soils presented heterogeneity of its chemical and physical attributes even in areas considered uniform. The aim of this study was to analyze the spatial variability of the granulometric fractions and of the chemical attributes of a sandy soil under no-tillage system. The work was developed at the Regional Pole of Agribusiness Technology Development from Paulista northwest located in Votuporanga/SP, on an experimental area under no-tillage system. The area measures about 1 ha with the sampling grid of 10 x 10 m. The area soil is a Red Latosol. The granulometric fractions and the chemical attributes of this soil were determined at a depth of 0-0.10 and 0.10-0.20 m. The data were analyzed using descriptive statistics and geostatistics tools for the spatial variability modeling. Most of the variables presented a moderate degree of spatial dependence. The granulometric fractions, water pH, KCl pH , Ca, Na, H, and C presented small variations of its levels in the two analyzed depths. The granulometric fractions and the soil chemical attributes did not present spatial relations between them. There was similarity of the boundary lines for the attributes related to the soil acidic reaction (pH, Al, and H). The spatial stability in the found depth for the granulometric fractions and soil chemical attributes demonstrate the potential management for the area in specific zones.