Variabilidade espacial e resposta espectral de atributos físicos e substâncias húmicas de um latossolo sob cafeicultura no Cerrado mineiro

Abstract

The physical and chemical attributes of the soil are important factors to be considered in the management of coffee culture, as they can limit the productivity of coffee crops. Thus, the objective of the present study was to analyze the spatial variability and the spectral response of the physical and chemical attributes of a clayey RED LATOSOL. The study was carried out in an area of 14 hectares cultivated with Coffea arabica. The soil in the area was sampled in the 0 to 0.1 m and 0.1 to 0.2 m layers, in a 112-point sampling grid. These samples were used in the determination of chemical indicators (humic acid and fulvic acid) and physical indicators by means of undisturbed samples taken through cylinders, the which were saturated to determine total porosity and soil density and deformed samples (soil aggregates and granulometry). Readings of soil resistance to penetration were also performed, using an impact penetrometer. The productivity of the crop was jointly determined. For each variable obtained, a statistical study of the main moments was carried out through descriptive statistics, aiming to characterize the probabilistic distribution and verify the data variability. The geostatistical methodology was also used in order to define the spatial variability model of the physical and chemical attributes of the soil involved in this study. Variographic analysis was performed using semivariograms. To make the maps, the GS + program was used. The spectral response was made through the normalized difference vegetation index (NDVI), correlating with the values sampled in the field. The use of geostatistics and the vegetation index together with the generated maps can be useful tools to assist the producer in making decisions related to soil management in areas with coffee cultivation.