Research on soil moisture dynamic under negative pressure irrigation

摘要

Negative pressure irrigation is a novel water-saving irrigation. The irrigation process does not require the external pressure equipment for water extraction. The soil suction was used to absorb water automatically from the source of water, which elevation is lower than the irrigation device. A new irrigation material named porous ceramic (ceramic, USA) combined with advanced negative pressure irrigation could keep the soil moisture always within the most suitable state for crop growth. Negative pressure irrigation could achieve the water-saving and the energy-saving target. In this paper, experiments were conducted to research soil moisture movement under negative pressure irrigation with porous ceramic douche. The results were showed as following. Negative pressure irrigation system using the porous ceramic douche could perform well when the inner negative pressure reached -15 cm. With the infiltration time, the soil moisture surround the porous ceramic douche became more and more big, and the soil moisture content increased gradually. Eventually, it reached the maximum soil moisture content value and fluctuated around the maximum soil moisture content value. The soil moisture was automatically controlled under negative pressure irrigation, which could always maintain soil moisture content in a certain range.