The Influence of Drying-wetting Cycles on Amino Sugars in Brown Soil

The influence of drying-wetting cycles on three kinds of microbes-derived amino sugars in brown soil with the addition of glucose and nitrogen fertilizer was investigated,through a laboratory incubation test.Relative contribution of microbial communities to drying-wetting cycles was explored in relation to the ratio of glucosamine and muramic acid.The study showed that,compared with the continuous wetting treatment,drying-wetting cycles promoted the accumulation of soil amino sugars,while the three individual amino sugars were decomposed due to the deficiency of substrate.In general,muramic acid was more prone to be affected by drying-wetting cycles,while the effect on galactosamine was small,demonstrating that the microbial transformation of amino sugar-derived soil nitrogen was changed.In addition,the microbial communities were changed in drying-wetting treatment compared with the continuous wetting treatment.At the prophase of incubation,drying-wetting cycles stimulated the bacterial growth,while stressed the fungal activity.With further increasing drying-wetting frequency,the fungal community appeared to be promoted and the bacterial growth was stressed.In the end,the microbial communities under drying-wetting cycles were similar with the continuous wetting treatment.