施氮肥对荒漠草原土壤微生物种群及微生物量的影响

目的]通过分析施氮肥对土壤微生物种群及微生物量,认识荒漠草原土壤微生物种群及微生物量对氮肥的响应,明确微生物对环境质量变化的指示作用.方法]应用稀释平板计数法和氯仿熏蒸-K2SO4提取法分别研究施氮肥对三种不同环境的荒漠草原土壤微生物种群及微生物量碳、微生物量氮(Bc,BN)之间的影响.结果]在土壤中细菌为土壤微生物的主要种群,其次是放线菌,真菌数量最少;施氮肥可以显著提高土壤中三种微生物种群数量,提高比例分别为13.5;-427.6;,7.8;-88.2;和16.7;-180.6;;施氮肥可以显著提高微生物量碳、氮,提高比例为29.8;-110.8;和51.2;-161.7;,施氮肥对土壤中微生物种群数量和微生物量的影响程度与施肥环境的降水量有关,降水量越大,影响程度就越明显,并且随着土壤深度的加深,施肥效果越不明显.结论]施氮肥改变土壤中微生物种群数量和SMBc,SMBN,不同施肥环境也可导致土壤中微生物种群数量和SMBC,SMBN的显著差异.

Effects of Nitrogen Fertilization on Desert Grassland Soil Microbial Population and Microbial Biomass

【Objective】The aim of the article was set to analyze the effects of nitrogen fertilization on soil microbial population and microbial biomass in desert grassland to know their response to nitrogen fertilizer and to clarify the indication effects of microorganism on environmental qualtiy change.【Method】The dilution plate count chloroform and fumigation-K2SO4 extraction of nitrogen were used to study the effect of nitrogen fertilization on three different environments:the microbial population and desert grassland microbial biomass carbon,microbial biomass N(BC,BN).【Result】Soil bacteria is the main specie in the soil,followed by actinomycetes and fungi is the least;N fertilizer can significantly increase all three populations of soil microbial,the ratio was increased by 13.5%-427.6%,7.8%-88.2% and 16.7%-180.6%,respectively;N fertilizer can significantly increas microbial biomass carbon,nitrogen,the ratio was 29.8%-110.8% and 51.2%-161.7%,respectively,effect of N fertilization on soil microbial populations and microbial biomass of the extent of precipitation and fertilization in the environment is related to the precipitation,the greater precipitation,the more obvious influence,the effect of fertilization is less obvious with the deepening of the soil.【Conclusion】Nitrogen changes in soil microbial populations and SMBC,SMBN,different fertilization environment can also lead to the difference of soil microbial populations and SMBC,SMBN.