葡萄分层地下滴灌滴头布设深度优化

为解决不同树龄葡萄根系的差异使得地下滴灌系统在布设应用中存在的困难,采用室内试验和HYDRUS-2D数值模拟相结合的方法,以宁夏和关中葡萄产区为例,研究了2种土质条件下分层地下滴灌土壤水分运动规律,提出了分层地下滴灌带最佳布设深度.研究结果表明,HYDRUS-2D模拟值与试验实测值具有良好的吻合度.地下滴灌带的埋深直接影响土壤水分的分布,2种土质下湿润体内部处于最佳含水率区间的土壤体积随滴头间距的增加而增大.通过适当增大浅层滴头埋深并减小深层滴头埋深可减小表层水分无效损耗.从避免水分无效消耗以及提高湿润体与根系匹配效果等角度出发,建议关中地区葡萄单滴头灌溉且适宜滴灌带布设深度为20 cm;宁夏贺兰山地区滴灌带布设深度以15 cm和45 cm为宜.

Optimizating of depth of drippers for layered subsurface drip irrigation of grapes

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.