Objective In order to reuse the saline-alkali wasteland in Tianshan mountain of Xinjiang, the cultivation effect on salt reduction and soil fertility improvement was detected.

Method Samples of 0 ~ 40 cm soil layer were collected from saline-alkali wasteland and cultivated wheat land. The spore density of arbuscular mycorrhizal fungi (AMF), glomus content, the number of culturable microorganisms, soil nutrients, soil pH value, electrical conductivity and soil enzyme activities of soil samples were determined. And principal component analysis (PCA) was introduced to studied cultivation effects on soil micro-environment.

Result The total glomus content and the spore density of AMF, numbers of culturable bacteria, actinomycetes, ammonifiers and azotobacter in each layer of cultivation were significantly increased compared with wasteland (P < 0.05), and the same trend in culturable fungi in 0 ~ 10 cm soil layer. Moreover, the pH value and conductivity of each layer of soil were significantly reduced by cultivation wheat, and contents of soil organic matter and available phosphorus were significantly increased at the same time in each soil layer (P < 0.01). The activities of urease, sucrase and phosphatase (acidic and neutral) in each soil layer in cultivated land were also significantly higher than those in wasteland (P < 0.01). Principal component analysis of soil indices showed that the contents of the glomalin, soil organic matter and available phosphorus, the number of culturable microorganisms such as actinomycetes and azotobacter, and the activities of phosphatase and urease in soil were the main factors to improve the fertilizer efficiency characteristics of soil. Thus, crop cultivation had positive effects on soil saline-alkali and fertility improvements, among which actinomycetes and azotobacter had extremely high positive effects, reaching 5437.04% and 6427.27%, respectively.

Conclusion The results illustrated that crop cultivation was beneficial to establish a new equilibrium relationship between plant and soil microenvironments, which effectively promotes the transformation of saline-alkali wasteland soil into arable land soil.