Response of the N-Cycling Associated Soil Microorganism to Simulated N Deposition in a Plantation of Cunninghamia lanceolata

The number of microorganism in soil is an important index in determining the change of the biochemical function of soil nitrogen cycle. While the current studies mostly focus on the microbial flora, the research on nitrogen cycling associated microorganisms is little. In this paper, the influence of deposition amount of short-term nitrogen deposition in different nitrogen forms on soil culturable azotobacter, nitric acid bacteria, nitrous acid bacteria and denitrifying bacteria is studied by a field simulation experiment. The amount of azotobacter in 0-10 cm soil layer was greater than that in the 10-20 cm layer. For the two nitrogen forms, the trend was inconsistent, low ammonium nitrogen promoted the nitrite bacteria growth, and the low nitrate nitrogen inhibited it. Nitrogen deposition forms had no significant effects on nitrate bacteria, low nitrogen deposition promoted the growth, and the high concentration restrained the growth. The quantity of nitrogen deposition had no significant effect on denitrifyi