Comparison of the TDR and ECHO systems to measure soil moisture, in a clayey soil and in sand - DOI: 10.4025/actasciagron.v26i3.1841

Abstract

TDR technique has been intensively applied around the world to measure volumetric soil water content. Although its good results, this system is rather expensive. Other systems have been developed to measure soil dielectric constant or electric potential under lower cost conditions. ECHO system has been used on some soil conditions with good results. For tropical soils conditions, there is no investigation about its application. This work was carried out to evaluate TDR and ECHO applications on a tropical soil Typic Paleudalf, which presents 73% of clay, commonly found at the Northeast region of Paraná, Brazil, and on a “washed sand” material. Mathematic models were fit, by linear regression analyses, to describe relations between soil volumetric water content and apparent soil dielectric constant (Ka) and between soil volumetric water content and electric potential. Results showed that both equipments can be used to adequately estimate soil water content, since careful calibrations were done before use