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土壤剖面中Mg2+的大量存在是土壤发生碱化的原因之一。测定了疏勒河昌马冲积扇缘镁碱化盐渍土土样的Mg2+碱度、Mg2+/Ca2+、pH值、HCO3-+CO32-等化学性质指标,分析了这些化学性质指标对土壤微生物生物量碳(氮)及其潜在可矿化氮的影响。结果表明:微生物生物量碳、微生物熵、微生物生物量氮随Mg2+/Ca2+、Mg2+碱度的升高而线性下降,而潜在可矿化氮随Mg2+/Ca2+、Mg2+碱度的升高而指数下降;另外,微生物生物量C/N与Mg2+/Ca2+和Mg2+碱度的反向变化关系说明,Mg2+碱化盐渍土环境中细菌在微生物群落中占优势。总之,高Mg2+碱度对土壤微生物而言是一种严重的胁迫环境,它使得微生物生物量变小、活性显著降低。
The presence of Mg2 + in the soil profile is one of the reasons for soil alkalization. The Mg2 + basicity, Mg2 + / Ca2 +, pH value and HCO3- + CO32- were measured in the magmatic saline soil of the Changma alluvial fan margin in the Shule River. The chemical properties of these samples were analyzed. Quantity of carbon (nitrogen) and its potential mineralizable nitrogen. The results showed that the microbial biomass carbon, microbial biomass and microbial biomass nitrogen decreased linearly with the increase of basicity of Mg2 + / Ca2 + and Mg2 +, while the potential mineralizable nitrogen decreased exponentially with the increase of basicity of Mg2 + / Ca2 + and Mg2 + In addition, the relationship between microbial biomass C / N and Mg2 + / Ca2 + and Mg2 + alkalinity showed that the bacteria in the Mg2 + alkalized saline soils dominated the microbial communities. In summary, high Mg2 + alkalinity is a severe stress environment for soil microbes, which leads to a decrease in microbial biomass and a significant decrease in activity.