Potassium deficiency exists in the coal mining subsidence area of Shendong coal mine. In this study, three kinds of clay minerals (quartz, potassium feldspar and illite) were mixed in different ratios and taken as the test matrix for investigating impacts of the amount of silicate bacteria C6X strain inoculum on effects of potassium release with different matrixes under different water control conditions. The aim is to find the most reasonable conditions for silicate bacteria C6X strain to release potassium to improve potassium deficiency in the studied area. In this way, the local soil can be utilized reasonably and effectively. The results show that the silicate bacteria increased the content of available potassium in the matrix. The changes of inoculation affected the effects of potassium release of the matrix. The best inoculum sizes of different substrates were all 10%. The optimum moisture content of the four substrates decreased with enhancement of the viscosity of clay mineral, being 120%, 100%, 70% and 55% of the maximum water holding capacity of the corresponding matrix. When the mass ratio of quartz: potassium feldspar: illite was 1:1:3, the effect of potassium release on the substrates of the silicate bacteria C6X strain was the best, being 1.44%. Therefore, the corresponding soil with moisture content of 55% can be best improved with 10% of silicate bacteria inoculation.

silicate bacteria  /  clay mineral  /  potassium release  /  moisture content  /  inoculum size