Factors Influencing Soil Salinization in Manasi River Basin, China

The objective of this study is to learn more about the distribution of salinized soil in the Manasi River Basin and the factors influencing soil salinization in the region. The following factors are considered:elevation, landform, groundwater depth, land use, and years of drip irrigation. The results showed that soil salt content increased as elevation increased to 350~400 m and then declined. However, the differences in salt content among different elevations were not significant. Soil salt content decreased in the following order:edge of the alluvial fan> central part of the alluvial plain> lower part of the alluvial plain> center of the alluvial fan> dry delta. At the edge of the alluvial fan and in the central part of the alluvial plain, soil salinity was greatest in the uppermost and lowermost depths of the soil profile. In the alluvial plain, the middle depth had the highest salt content. Groundwater depth had significant effect on the soil salt content. The soil salt content increased significantly as groundwater depth increased. There was significant difference in soil salt content among land use types. The salt content was highest in wasteland soil. The middle soil depth under wasteland had less salt than the upper and lower soil depths. In the cultivated field, the soil salt content in the 0~100 cm depth was low. As the number of years of drip irrigation increased, soil salt content in the 0~100 cm depth decreased. Soil salt content in the surface depth after 1 years of drip irrigation was not significantly different from that after 3 years drip irrigation. Soil salt content after 8 years of drip irrigation was not significantly different from that after 10 years of drip irrigation. In conclusion, soil salt content in the Manasi River Basin was significantly affected by landform, groundwater depth, land use, and the number of years of drip irrigation. These factors also significantly affected the distribution of salt in the soil profile