Study on the soil moisture movement under infiltration irrigation

To explore moisture movement under infiltrating irrigation and contribute a theoretical basis for agricultural production, we carried out a laboratory simulation experiment to study soil moisture movement under different pore diameters, pressures, and bulk densities. Results showed that the wetting front of both sandy soil and loamy soil increases gradually under three hydraulic head pressures (0.02, 0.01, and 0.005 MPa) as irrigation proceeds. Viewed from the entire shape of the wetting front, the wetting front of Ø25mm irrigation pipeline with 2.5 mm pore diameter is uniform. Under two bulk densities (1.54 and 1.43 g·cm^-3), given 0.02 MPa pressure, Ø25mm irrigation pipeline with 2.5 mm pore diameter, the wetting front of soil rises gradually as irrigation continues. The combination of a 10-year-old root distribution system of fruit trees, 0.02 MPa head pressure, and Ø32mm irrigation pipeline with 2 mm pore diameter could meet the irrigation demand of red dates.