Depletion and restoration of soil water in different cultivating systems in Gully Region of Loess Plateau

Soil desiccation is one of the key factors to influence the sustainable development of crop production on the Loess Plateau of China. So it has a great significance for the sustainable development of crop production to research the form and recovery of the dry layer of soil. In this article, depletion and restoration of soil water in different cultivating systems were analyzed based on the long-term experiment data at Changwu Agriculture Experimental Station. The results showed that comparing with bare land, the time in which maximal reduction of soil water occurred was August or September in maize land; May, June or July in wheat land; June or August in alfalfa land. In the growth period, from 1985 to 1990, the average soil water in 0-2 m soil layer of maize land, wheat land and alfalfa land decreased by 32.52, 60.27 and 86.47 mm compared with that of bare land. The restoration of soil water in different cultivating systems was different. Soil water of entire dry layer in maize land was thoroughly restored in high precipitation years. Soil water of part dry layer (0-3 m) was restored in wheat land in high precipitation years or in heavy rainfall months, but it was relatively hard to restore to its original level. Soil water in alfalfa land restored to a certain extent in the 0-3 m soil layer in rainy years but hard to restore in the 6-10 m soil layer.