Effect of soil straw cover on evaporation, transpiration, and evapotranspiration in sugarcane cultivation

Residual straw affects the physical, chemical, and biological attributes of soil and can influence plant transpiration and the evaporation of water from the soil. Therefore, in this study, we evaluated the effect of straw on evaporation and transpiration of sugarcane. The experiment was conducted in a 2.5 ha area irrigated via a central pivot. The experiment consisted of two treatments, namely, with and without straw removal of soil. Evaporation was determined by means of equations and transpiration with sap flow sensors using the heat balance method. Evapotranspiration of the crop was measured using the Bowen ratio method and compared with the sum of the collected soil evaporation and transpiration data. On the basis of relationship analysis between the evapotranspiration of the crop measured using the Bowen ratio method and the sum of the sap flow combined with estimates of the evaporation of soil water, we obtained coefficient of determination values of 0.65 and 0.69, and angular coefficients of 1.01 and 0.96 for treatments with and without straw, respectively. We accordingly found that the use of straw on the soil reduces the evaporation of soil water and increases the transpiration and evapotranspiration of the crop.