| Soil salinization will not only cause soil degradation, land resource shortage, and ecological environment deterioration, but also limit the sustainable development of agriculture. Microbial method is a sustainable ecological improvement method with less cost and manpower. There are a large number of potassium-containing minerals in saline soil. If the potassium in these minerals is used, it can not only improve environmental problems, but also improve soil fertility. In this study, three salt-tolerant strains were isolated and screened from sulfate-type saline soil, and batch experiments were carried out in the laboratory with soil mineral potassium feldspar as the substrate. The potassium-solubilizing performance and mechanism were studied and analyzed by flame atomic absorption spectrometry, three-dimensional fluorescence spectroscopy-parallel factor analysis, SEM, etc., and the optimal potassium-solubilizing strain was selected for experiments to explore the effect of the strain on the change of potassium in saline soil. The results showed that the three strains were Gram-positive Bacillus, and could tolerate extreme saline-alkali environment, and the potassium release amount could reach 18.8 mg / L. The three strains can reduce the pH of the fermentation broth and have a certain degree of dissolution of insoluble potassium-containing minerals. It is preliminarily speculated that the strain dissolves minerals by secreting acidic substances. The available potassium in saline soil increased by 13.76 mg / kg after the application of the bacteria, and the bacteria could be used as a candidate strain for saline soil improvement. This study revealed the dissolution mechanism of the selected salt-tolerant strains on potassium feldspar, and explored the effect of salt-tolerant indigenous bacteria on the change of potassium in saline soil, which provided a theoretical reference for the improvement of barren saline soil. |