Variabilidade da constante dielétrica do solo em função de sua umidade e classe.

Abstract

The purpose of this work is to cordate dielectic constant and soil moisture experimental data in way to produce equations that can be applied on soil moisture estimation. On this work it is presented experimental data and evaluation on soils moisture determination by means o f transmition and reception of micro wave signal. For this,it was utilized a TDR technique (Time Domain Reflectometry). It was applied a cable tester that generates eletromagnetic waves in the frequency of 1.2 Mhz. This equipment allows to measure the dielectric constant of soil that can be correlated with its soil moisture. About this correlation there are several ideas. There are those authors that recomend a "universal" equation to correlate dielectric constant with moisture. Others those recomend that every soil have their own correlation. These correlations are calibrated to each case by statistical to experimental data. The test and measuments were corred out on laboratory. The experiments were applied to five diffent soils. Litossolo, Podzolico Vermelho - Amarelo, Arei quartzoza, Latossolo Vermelho Escuro e Latossolo Vermelho Amarelo. With data obtained on test of each kind of volumetric soil moisture and dieletric constant determined with TDR equippment were correlated. The fited curves to several soil were compared to Topp curve.New curves are proposed to determine the volumetric soil moisture as wellas the function of dieletric constant, taking in account the kind of soil.