Estudo e aplicação de modelo para balanço hídrico do solo em sistema agrícola conservacionista nos Campos Gerais do Paraná

Abstract

The soil water balance (BHS) is an important tool for the planning and management of cultivated plants, as it allows estimating and informing the water availability for crops, the formation of surface runoff, among other information related to water in agricultural systems. The reliability of this information is strongly dependent on the quality of the information collected, as well as the mathematical models applied to estimate each component of the BHS. In this sense, the research aimed to evaluate the ability of the soil water input and output model developed by the Laboratory of Irrigation and Agricultural Hydrology at UEPG to estimate soil moisture and other BHS components in a grain producing area in the no-tillage system (SPD), with mechanical practice of soil conservation, in the Campos Gerais region of Paraná. The experiment was carried out at the Escola Farm of the State University of Ponta Grossa, Campos Gerais – PR, during the cultivation of black oats, soybeans and wheat, in the winter and summer harvests between 2020/2021, in two experimental areas of approximately 1.5 ha, with and without the presence of agricultural terraces. The moisture information estimated by the ESAS model was compared with the moisture measured in soil moisture sensors of the FDR type, which were duly calibrated, using the Root Mean Squared Error (REQM), the coefficient of determination (R2), correlation and concordance index “d”. The proposed soil water balance

model was effective in estimating surface runoff, predicting the flows observed through the H- trough. The FDR-type moisture sensor proved to be acceptable for monitoring the water content in the soil. however, the FRD probe requires calibrations with reasonable goodness of fit. The model proved to be suitable for estimating soil moisture in the development zone of the root system of winter crops.