Abstract:

In order to study spatial-temporal variability properties of soil water on alfalfa grassland under local limited precipitation and land impoverishment conditions in loess hilly region of south Ningxia, and provide data support for efficient utilization of local limited water resource, soil water were monitored on alfalfa grassland based on field multiple positions experiments with different grow years as test treatments. The results showed that the fluctuation of soil water storage at 0-100 cm was decisively effected by the precipitations in loess hilly region of south Ningxia, soil water continuously decreased before rainy season coming, but it was significantly increased after rain, which was consumed gradually until freeze-up period. Soil water on alfalfa grassland with different grow years had different change laws below 100 cm. soil water on alfalfa grassland with 5 grow years had more supplement than 2-years at 100-200 cm. So, the 100-200 cm soil layers of alfalfa grass land with 2 years could be viewed as supplying layer for surface soil water, which could be viewed as transition layer of alfalfa grassland with 5 years.