Responses of soil microbial prosperities to different management modes in typical steppe, Ningxia

Soil microorganism community of grassland is a driver of soil nutrient cycle, which can sensitively reflect changes of ecological environment of grassland, and is always looked as an indicator for soil quality. Present study was conducted on the typical steppe grassland in Ningxia to investigate soil microorganism properties and the relationship between microorganism properties and soil organic content under different management modes including enclosure, grazing and horizontal ditch. The results showed bacteria amountactinomyces amountfungus amount in 0-40 cm soil depth of research area. Bacteria and actinomyces number increased with enclosure time increasing. Fungus amount in grassland enclosed for 5 years was the highest in all treatments. The total amount of microorganism, microbial biomass carbon, and nitrogen increased with the increasing of enclosure time, and were the lowest in grazing grassland. There was no advantage of microorganism properties in horizontal ditch grassland. In different soil layers, the highest microorganism amount was observed in 5-15 cm soil depth, and the lowest amount was found in 25-40 cm soil depth. There was a significantly positive relationship between microorganism amount and soil organic content.