Estimativa de variáveis do balanço de água no solo com e sem cobertura em dois sistemas de irrigação localizada para a cultura da bananeira

Abstract

Knowledge of soil water dynamics is essential for accurate estimates of soil water balance, which contributes to improving irrigation management and increasing water use efficiency in irrigated agriculture. This work aims to make accessible contributions in the soil-water-plant relationships of BRS Princesa banana cultivar through alternatives for estimating percolation, evapotranspiration, root water extraction and unsaturated hydraulic conductivity determination from theories in the literature of water dynamics under unsaturated soil conditions. For that, two experiments were conducted, one in lysimeter drainage and the other in field at Embrapa Cassava and Fruit in Cruz da Almas-BA. The time interval for calculating percolation of water by soil water storage variation was determined. From which it was estimated the extraction, evapotranspiration and unsaturated hydraulic conductivity from the variation of water storage in the soil profile monitored by humidity sensors. The obtained data were submitted to analysis of variance comparative tests of means. The total percolation of water in the soil in the layer of 0.60-0.80 m can be estimated from the time interval of 6 hours. It is feasible to estimate the evapotranspiration of the crop, water extraction by the banana roots and percolation in the layer immediately below the root zone from the water balance in the soil. The methods of moisture variation and storage variation in a layer estimate the unsaturated hydraulic conductivity with good accuracy over the Hillel method.