Resistência mecânica de um latossolo vermelho à penetração : comparação de penetrômetros, ajustes de modelos e correção da umidade

Abstract

The mechanical resistance of the soil to the penetration is considered the most adequate property to express the degree of soil compaction and, consequently, the ease of soil penetration. The objective of this work was to evaluate the mechanical resistance to the penetration of a Red Latosol and the comparison of two penetrometers with model adjustments and moisture correction. The experiment was carried out from May to October 2018, at the Federal University of Mato Grosso - UFMT, Campus university de Rondonópolis - CUR. Between the 0-20 cm layer some physical soil properties such as density, porosity and soil penetration resistance were evaluated. For the comparison of the two penetrometers, field and laboratory evaluations were carried out and the laboratory evaluations were determined through the collection of samples in the layer between 0-60 cm. In the determination of the penetration resistance correction for standard moisture two methods of Busscher and an alternative were compared. The data obtained from mechanical resistance of the soil in the laboratory were submitted to four models of adjustments, being the model of Jakobsen e Dexter (1987) that obtained better adjustment to the data. There is significant divergence in the values of resistance to penetration for the same range of humidity when compared the values obtained by the two apparatuses presenting the field evaluation smaller values. For a standard moisture of 20% the data of soil mechanical resistance to measured penetration and reference resistance showed a positive correlation.