Avaliação de sondas artesanais para medida da umidade volumétrica do solo com equipamento de TDR

Abstract

Water is important for agriculture, and rational management is essential for plant development. There are several indirect methods to measure the water content in the soil, providing moisture instantly, such as the Time Domain Reflectometry (TDR) technique, which measures the dielectric constant of the medium in which it is inserted. However, this equipment is imported, with a high acquisition cost and needs calibration. Thus, the present work had as objective to test the efficiency of TDR probes made with national materials and to verify the effectiveness of the calibration equations of Top (1980) and Ledieu (1986), for an Latossolo Vermelho of the experimental area of the Federal University of Fronteira Sul, Cerro Largo campus. The artisanal probes were similar to the standard probes, when compared by the Tukey test at 5% significance, in the conditions of saturated soil, soil moisture condition in the field capacity, soil moisture condition at the permanent wilt point and condition of humidity below the permanent wilt point, where air-dried soil was used for this condition, proving its efficiency, however, the calibration equations were not adequate, requiring a new equation based on the data obtained for greater precision of the soil water content.