模拟氮沉降和刈割对内蒙古典型草原土壤微生物量的影响

Effects of Stimulated Nitrogen Deposition and Cutting on Soil Microbial Biomass in a Typical Steppe in Inner Mongolia

为探讨大气氮沉降对草原土壤微生物量的影响,采用模拟大气氮沉降的方法对试验小区进行施N处理,研究了不同施N水平下刈割对土壤微生物量C、N的影响。结果表明:不同施N水平对土壤微生物量C、N没有显著影响,但是有增加土壤微生物量C、N的趋势;在刈割和施N的交互作用下降低了土壤中微生物量C、N的含量。不同施N水平能降低草原植被根系生物量、促进土壤酸化。施N量为每年20g/m2时对土壤微生物量C、N的抑制性最强。

In order to explore the influence of soil microbial biomass by nitrogen deposition in steppe, the way of stimulated nitrogen deposition was applied to treat with plots via N, the influence of cutting on soil microbial biomass C and N at different N-treated levels was researched. The results showed that different N-treated levels didn＇ t have significant influences on soil microbial biomass C and N, but had the trend of improve soil microbial biomass C and N; interaction of cutting and N-treated decreased soil microbial biomass C and N. Different N-treated levels could decrease roots weight of grassland vegetation, promote soil acidification. The constraint to soil microbial biomass C and N was the best under N-treated of 20 g/m2 one year.