Evaluation of soil water losses under irrigation saving techniques in a semi-arid region in Tunisia

Abstract

In arid and semi-arid regions, managing agricultural water for irrigation is essential to cope with water scarcity and maximize crop yields. In this study, an experiment was conducted on a potato crop in the Manouba region (lower valley of Medjerda, Tunisia). The experimental protocol consisted of four water treatments utilizing water-saving irrigation techniques: FI (Full Irrigation 100%): irrigation with 100% of crop water requirements. DI (Irrigation 75%): deficit irrigation with the application of 75% of crop water requirements. PRDRight (Irrigation 50% on the right side): Irrigation by partial root drying. PRDLeft (Irrigation 50% on the left side): Irrigation by partial root drying. Simulation of soil water profiles was carried out by the Hydrus-1D model. The soil hydraulic properties were calibrated according to the experimental conditions using an inverse modeling technique. According to the obtained results, simulated soil water profiles were close to those measured. Indeed, the calculated NRMSE values are low, indicating the reliability of Hydrus-1D as a decision support tool to optimize water irrigation management. These results were then used to investigate the effects of a 2 °C temperature increase on soil water loss, and it was determined that the impact was insignificant. HIGHLIGHTS Arid and semi-arid need irrigation water saving techniques.; Deficit irrigation and partial root drying techniques can be a good alliterative to drip irrigation.; Simulation of water flow in the unsaturated soil allows the estimation of soil water storage.; Soil water loss under irrigation saving techniques is related to the applied irrigation doses.; The increase in temperature has no significant effect on deep percolation.;

Keywords

• hydrus-1d
• infiltration
• irrigation
• potato crop
• tunisia
• water saving techniques