ESPACIALIZAÇÃO DA GRANULOMETRIA DO SOLO EM LATOSSOLO VERMELHO EM CERES (GO)

Abstract

Soil texture mapping is an important tool, as it generates information for more accurate soil and fertility management in the sugarcane crop. The objective was to determine and spatialize the soil granulometry in a sugarcane area at the Sugarcane Research Unit in Ceres (GO). The experiment comprised an area of 285 x 60 m with sampling in a mesh of 15 x 15 m at depths of 0-20 and 20-40 cm from January 2020 to January 2021. The attributes evaluated were: clay (ARG), sand (ARE), silt (SIL) and natural clay (AN). Descriptive statistics such as minimum, maximum, mean, median, standard deviation, asymmetry, kurtosis and normality were applied. The data were adjusted to theoretical models to obtain the semivariograms, selecting the best model and applying the cross-validation technique. The attributes were interpolated by ordinary kriging, followed by the construction of iso-occurrence maps. The clay content varied from 367.1 to 578.3 g kg-1 and 411.17 to 628.8 g kg-1, with averages of 490.20 and 523.16 g kg-1, for layers 0-20 and 20-40 cm respectively, being classified as clayey for both layers. Natural clay presented averages of 43.25 and 37.52 g kg-1 for the 0-20 and 20-40 cm layers, respectively. The coefficients of variation (CV%) for total clay were low (<10%), medium sand and silt (10.31-25.1%), and very high natural clay (90.94-99.34). Spatial dependence ranged from moderate to strong, with adjustments predominantly to spherical and exponential models. The geostatistical analysis proved to be adequate for the study of the granulometry of the RED LATOSOL, as there was spatial dependence. Future studies in the area can be carried out in a 22 m grid, as they present range values greater than 22 m. The area presents greater spatial uniformity in the layers of 0-20 cm for silt and 20-40 cm for total clay and sand, indicating high variability for natural clay. The spatial distribution of clay in the area serves as a subsidy for decision-making in soil management and fertility.