Soil moisture distribution in different cultivating systems in mountainous area of south Ningxia Hui Aotonomous Region

The study of soil moisture distribution of dry land crops can supply scientific evidences for water resource use. The article studied dynamic changes of soil water of five kinds dry land- winter wheat, flax, potato, alfalfa and natural grass in different stages. The results showed that temporal variations of soil moisture on different dry land crops were similar. All five kind crops include “soil moisture content raising period” and “soil moisture content declining period”, that dividing line were at the middle of July. Soil moisture of annual crops (as winter wheat, flax and potato) were more higher perennial crop (as alfalfa and natural grass) in whole growing time. The soil moisture vertical distribution of winter wheat, flax and potato were ‘topsoil highness, subsoil lowness’, alfalfa and natural grass in reverse. Topsoil moisture movement was obvious, subsoil moisture movementwas inconspicuous all dry crops. In growing time, rainfall didn’t satisfy the all crops needs. The raising soil moisture in autumn is pivotal for harvest of dry crops.