Objective The aim was to explore the spatial variation characteristics of soil salinity in arid and semi-arid areas, which could provide a theoretical basis and reference value for the improvement of salinized soil of desert steppe vegetation types.

Method This paper took the spatial distribution of soil salinity in desert steppe as the research content in the 144 km² area around Haba Lake Nature Reserve in Yanchi County in May of 2019. Soil samplings were carried out by using GPS positioning technology and grid sampling method, and the spatial variation characteristics of soil salt contents at different depths were explored by using the combination of classical statistics and geostatistics.

Result ① The soil pH value in the study area was between 8.85 ~ 9.03, and the soil salt contents were generally high, ranging from 8.692 ~ 16.728 g kg⁻¹, and the soil salt content in the 0 ~ 20 cm soil layer was the largest, which was significantly higher than that of the other layers (P < 0.05). The variation coefficients of soil salinity in each layer ranged from 0.642 ~ 0.794, which belonged to the moderate variation. ② The best theoretical model of the semi-variance function of soil salinity in 0 ~ 20 cm, 20 ~ 40 cm and 40 ~ 60 cm soil layers was the exponential model, and the best for 60 ~ 80 cm and 80 ~ 100 cm soil layers was spherical models. ③ The ranges were 2.84 ~ 14.63 km, and with the increase of soil depth, the range gradually increased. The block-to-base ratio (C₀/Sill) decreased gradually, and the spatial autocorrelation was enhanced.

Conclusion The spatial distribution of soil salinity in each layer was basically the same, and the distribution pattern was mainly patch-like distribution pattern, except for the strip-like distribution pattern of soil salinity in the 20 ~ 40 cm soil layer, and the degree of soil salinization gradually decreased from northeast to southwest.