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... |