Average Soil Particles Diameter to Predict some Soil Physical Properties

Abstract

The main purpose of this work was to estimate soil physical characteristics that are time consuming, developing mathematical models based on others characteristics obtained routinely on soil laboratories. Thirteen soils were selected varying from 40 to 590 g  kg-1 of clay content. From these soils, undisturbed and bulk samples were obtained at 5 cm to 15 cm soil layer, and determined in laboratory, chemical (sorptive complex, pH and potential acidity) and physical (bulk density, dessorption curve and porosities)  characteristics. Correlation was established among optimum soil water  content and soil water at field capacity and the chemical and physical  soil characteristics obtained. The soil characteristic that showed the  highest correlation coefficient with optimum water content (r = 0.93)  and with water at field capacity (r = 0.93) was the average soil particle  diameter (ASPD). This soil attribute can be obtained from most soil  surveys existing in Brazil and it is the sum of the multiplication of  average particle diameter of four particle classes to their soil content.  Soil water content at -1500 kPa was also well correlated to ASPD; this  allows calculating the amount of available water for plants.