%A DU Hulin,*, LIU Junjiang, LIU Rongguo, MA Zhenyong,, LIU Ligang, ª¤WANG Yongjun, ZHU Rui, ZHANG Bo, NIU Jinshuaiª¤ %T Characteristics of soil moisture growth and decline in sandy land under root irrigation %0 Journal Article %D 2018 %J Journal of Drainage and Irrigation Machinery Engin %R 10.3969/j.issn.1674-8530.17.0131 %P 617-624 %V 36 %N 7 %U {http://zzs.ujs.edu.cn/pgjx/CN/abstract/article_2474.shtml} %8 2018-07-25 %X Irrigation experiments were conducted on artificially planted annual Halotylon ammodendron in the Sapotou Environment Protection Ecological Demonstration Base in Zhongwei of Ningxia by using a straight-inserting root irrigation technique. Soil water variations in 20-100 cm soil layer were observed continuously in 24 h by TDR probe. The characteristics of soil water increase and depletion are as follows: soil water increase can be divided into two stages, the initial 6 h after irrigation is a rapid increase stage with an increase rate of 55.36%/h. Following that there is a slow increase stage with an increase rate of 0.57%/h, i.e. just 1.03% of the rate in the first stage. Soil water depletion can be divided into two stages: the initial 6-8 h after stopping irrigation is a rapid soil water depletion stage with a depletion rate of 7.58%/h. Then there is a slow depletion stage with a depletion rate of 0.58%/h, and the soil water depletion period is 5 d. The minimum threshold of soil water deflation is 1.45%, which is of great significance to artificial plant growth in Shapotou, because the soil moisture content is 1.45% -4.0% in that area. The soil water depletion processes can be best fitted by a power function equation. In 20 cm depth shallow surface soil layer, soil moisture of straight-tube root irrigation is 170% higher than that of surface drip irrigation. The effective water holding time of straight-tube root irrigation is 12 times the surface drip irrigation. Straight-tube root irrigation has better soil moisture conservation than surface drip irrigation.ª¤