Researchers Investigate the Distribution Characteristics of Soil Water and Salt Content with Different Soil Textures around the Kalamiji Oasis

Shelterbelts are the protection screens of agriculture and oases, and the economy is based on the local agriculture. Kalamiji Oasis, which is the sink oasis for the Tarim River, is located in an extremely arid area with strong evaporation and low precipitation. Salt originating from mountains and upper and middle river areas result in high salinity levels in the groundwater and severe salt accumulation in low-lying areas. Due to the lack of irrigation, serious soil water loss occurs via soil evaporation leading to a salt accumulation in the upper soil layers. As a result, a large number of shelterbelts have died around the Kalamiji oasis. It is not clear whether this is a result of the low water levels or the effects of high salinity. If it is the combined effect of low water content and high salinity, then there is a need to find a way to ameliorate these effects.

Therefore, based on long-term monitoring data for soil water, salt content, and groundwater characteristics taken from shelterbelts where there has been no irrigation for at least 5 years, ZHAO Xinfeng et al. investigated the distribution characteristics of soil water and salt content in soils with different textures around the Kalamiji Oasis. The relationships between soil moisture, soil salinity, and groundwater level were analyzed using 3 years of monitoring data from this oasis.

The results showed that the variation trend in soil moisture with soil depth in the shelterbelts varied depending on soil texture. The soil moisture was lower in sandy and loamy shelterbelts and higher in clay shelterbelts. Salinity was higher (about 3.0 mS/cm) in clay shelterbelts and lower (about 0.8 mS/cm) in sandy shelterbelts. There was a negative correlation between soil moisture in the shelterbelts and groundwater level. Soil moisture decreased gradually as the depth of groundwater table declined. However, there was a positive correlation between soil salinity in the shelterbelts and the depth of groundwater table. Salinity increased gradually as groundwater levels declined. The result was published in Environmental Monitoring and Assessment in December 2013.