DefinePK

Abstract

A compacted soil shows a deterioration in physical properties, affects the availability of water and the growth of plants. The amount of useful water in the soil is a characteristic of it that defines its agricultural aptitude and corresponds to the water that can be absorbed by the plants. This study aims to evaluate the relationship of water parameters, field capacity (FC) and permanent wilting point (PWP), with the optimum moisture content (OMC) in clay soils. The physical properties of the soil, such as texture, real and bulk density, maximum dry density (MDD) value and OMC are analyzed. The Proctor compaction test is used to determine the MDD and its OMC; a Richards Pressure Chamber is utilized to obtain the FC and PWP and a tension table to acquire other moisture retention parameters. The results indicated that in Latossolos (oxisols) of Brazil (LV, LVA) soils, the ratio for FC with water retention value of -100 hPa is 100% of OMC, and in Vertisol soil for -300 hPa is 100% of the OMC. For Latossolos (LV, LVA) soils, the PWP (-15000 hPa) is 80% of the OMC and for Vertisol soil 80% of the OMC. With statistical analyze a polynomial regression model is obtained to relate the water contents to OMC. This regression shows that exist a direct relationship between water retention and OMC values.