Calibração da sonda de capacitância Diviner 2000® em um argissolo.

Abstract

Capacitance sensors are alternatives to most common soil water content methods, providing readings safely and rapidly with depth. In this study, a capacitance probe (Diviner 2000®) was calibrated in a Red Yellow Argisoll at Experimental area of Embrapa Meio-Norte, Teresina, Piaui State, Brazil. Six access tubes were installed in a 5 by 2 m grid system. Three moisture levels (dry, moist and satured soil) were applied in two replications. Readings of device were made for every 0.1 m until 1.0 m depth as well as collecting of soil samples to determine the volumetric soil water ( v). The calibration equation, derived by regression analysis, was significantly related with measurements of equipment with high correlation (R2 =0.93) and lower standard error (0.014 m3 m-3). Despite underestimating values of v by 9.2%, the manufacture’s calibration presents in Diviner 2000® is acceptable for this soil.