水保所知识产出(1956---)知识库

A subsurface irrigation system with ceramic emitters (SICE) without a pump has been developed to limit energy
consumption and reduce greenhouse gas emissions. Yet whether SICE can be used in low-pressure conditions has
not been tested; moreover, there is no index for evaluating the irrigation quality of SICE. Laboratory experi-
ments, with six treatments, were conducted to study ceramic emitter hydraulic characteristics in the air and soil
under different working pressure heads and emitter types. The results indicated that when H increased, the
emitter discharge increased linearly, and the discharge deviation decreased in the air. With increased H in the
soil, the emitter discharge, soil water content, and soil water content uniformity increased, and the discharge
deviation decreased. When H was greater than or equal to 20cm, the discharge deviation in the soil was less than
that in the air, and the soil water content uniformity was higher than 80 %. The soil water content uniformity
could be used in the evaluation of the irrigation quality of SICE based on the reliability and convenience of
observation. To make the best use of soil water potential on the outflow of the emitter, reduce the discharge
deviation, and improve soil water content uniformity, the working pressure head of SICE should be higher than
20 cm.