Optimizating of depth of drippers for layered subsurface drip irrigation of grapes
DU Yichao1,2, CAI Yaohui1,3,4*, ZHANG Lin1,2,3,4, ZHU Delan4, ZHANG Guangdi5,LI Yuding5, JIA Yinan5, WU Yong6
1. Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi 712100, China; 2. Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; 3. Institute of Water-saving Agriculture in Arid in Northwest A&F University, Yangling, Shaanxi 712100, China; 4. University of Chinese Academy of Sciences, Beijing 100049, China; 5. Agricultural College of Ningxia University, Yinchuan, Ningxia 750021, China; 6. National Agro-tech Extension and Service Center, Beijing 100026, China
Abstract：It is difficult for the subsurface drip irrigation wetting body to better match the root system water absorption at different growth stages. In order to solve the problem, some researchers have proposed a new type of subsurface drip irrigation, layered subsurface drip irrigation system. A combination of laboratory experiments and HYDRUS-2D numerical simulation was used, the two major grape-producing areas in Ningxia and Guanzhong were taken as examples to study the soil water movement law of layered subsurface drip irrigation, and the layered subsurface drip irrigation optimal placement depth was proposed. The research results show that the simulated value of HYDRUS-2D has a good agreement with the measured value. The depth of the drippers directly affects the distribution of soil moisture, and the soil volume within the optimal water content range under two types of soil increases with the increase of the distance between drippers. Appropriately increasing the depth of the shallow dripper and reducing the depth of the deep dripper can reduce the inefficient loss of water. In order to avoid inefficient consumption of water and improve the matching effect of wetting body and root system, it is recommended that the appropriate depth placement with a single dripper of grapes in Guanzhong area is 20 cm. The depth of dripper placement in Ningxia are preferably 15 cm and 45 cm.
