LIU Taotao1,2, WANG Yonghui1,2, ADILA Abrimiti1,2
(1 Key Laboratory of Lake Environment and Resources in Arid Areas, Xinjiang Uygur Autonomous Region Urumqi 830054;
2 Xinjiang Normal University, Xinjiang Uygur Autonomous Region Urumqi 830054)
Abstract：In order to explore the interaction between salt crust and soil property in Aibi Lake wetland and to disclose the natural factors that influence the thickness of salt crust, the method of field investigation combined with laboratory test was adopted. Totally 60 representative sample points were selected, with 30 in the wetland and 30 without SSC, and the spatial and vertical variations of soil properties (volume weight, OM, water content, salt , total-P, total-N and pH) with and without salt crust in the study area were analyzed, and the influence of wind speed, temperature, humidity and precipitation on the salt crust thickness was discussed. The results showed that:(1)The average of total salt and water content in the salt crust-covered soil were 27.7 g/kg and 6.8 g/kg, respectively, these were significantly higher than that in the soil without SSC cover(17.8 g/kg for total salt and 10.7 g/kg for water content).The contents of organic matter, total phosphorus, and total nitrogen in soil covered by SSC were 6.9, 0.88, and 0.63 g/kg, respectively, these values were significantly lower than OM(8.8 g/kg), total-P (1.05 g/kg), and Total-N(0.87 g/kg) in soil without SSC cover. Soil with SSC were more alkaline and had higher bulk density.(2)The total salt content, density, and pH of soil under the salt-crust cover decreased with the increase of depth, while the water content, total phosphorus, and total nitrogen increased with the increase of depth. Salt crust thickness was positively correlated with total salt (0.676**), water content (0.513**), and bulk density (0.484*), while was negatively correlated with organic matter (-0.426*), pH(-0.402*), total phosphorus (-0.233), and total nitrogen (-0.303). The correlation decreased gradually with the increase of depth.(3)Principal component analysis showed that when the salt crust thickness was > 3 cm, the total salt, moisture and wind speed had the largest contribution to the salt crust thickness, with the weight of 0.42, 0.25 and 0.17, respectively. In a word, salt crust can improve the soil water retention and increase the soil bulk density, but it is not conducive to the accumulation of nutrients and will make soil alkalization and salinization more intense. To sum up, the formation of salt crust was mainly affected by the total salt, moisture of soil and wind speed.
Keywords: Aibi Lake wetland; salt crust of soil; soil property; influencing factors
EARTH AND ENVIRONMENT Vol.49, No.3, Tot No.341, 2021, Page 285-296
