The heavy saline alkali soil in Hetao irrigation area has the characteristics of poor structure and low water conductivity

and the fresh water resources in this area are in short supply. In order to improve the infiltration performance of soil water and reasonably develop and utilize the brackish water resources

a sand hole can be set under the dripper and the brackish water can be used for irrigation. In order to find out the influence of different salinity and brackish water drip irrigation on the distribution of water and salt in soil under the sand hole planting

this study adopted the indoor simulation test of 50 cm×50 cm two-dimensional soil tank

and set four different salinity treatments of distilled water (0 g/L)

2.0

3.0 and 4.0 g/L

the experimental duration was 100 hours. The results showed that the soil water content was higher in the saline alkali soil with the depth of 5 cm and at the distance of 15~20 cm from both sides of the dripper and 25 cm below the dripper. The soil water content of the sandy soil increased with the increase of water salinity. The soil water content of the saline alkali soil increased first and then decreased with the increase of the salinity. When using 3.0 g/L water drip irrigation

the water content of the saline alkali soil was the largest (coefficient of variation was 7.64%). Therefore

using 3.0 g/L water irrigation could effectively improve the soil moisture content under sand hole planting; after 100 hours of infiltration

the salt was mainly concentrated at 25~30 cm below the dripper. In the sand hole structure test

when the salinity of irrigation water was 4.0 g/L

the average conductivity of soil was the largest (coefficient of variation was 50.59%). The effect of salt leaching in horizontal direction was better than that in vertical direction

and the lower salinity of irrigation water gave the more significant leaching effect.The desalination rate of distilled water treatment was 13.99%

and the salt accumulation rates were 7.93%

14.57% and 30.05% for irrigation the salinity of 2.0

3.0 and 4.0 g/L

respectively. The desalination radius decreased with the increase of the salinity

and the difference between the salt accumulation of 3.0 g/L and 2.0 g/L was not significant (P=0.460 > 0.05)

which two were significantly different from that of 4.0 g/L (P=0.024 < 0.05). Combined with the spatial distribution law of soil water and salt

3.0 g/L brackish water could be used to improve the soil water content of saline alkali soil

control the salt accumulation in sand holes

and improve the soil water conservation of root layer.