不同土壤微生物量碳与有机碳矿化的关系研究

采集洞庭湖区稻田土壤、林地土壤和荒地土壤,在实验室进行培养试验,分析3种不同利用方式下的土壤微生物量碳含量与有机碳矿化的关系。通过试验分析得到:3种土壤的微生物量碳含量随着土层的加深而减少,土壤中微生物量碳含量由高到低为稻田土壤﹥林地土壤﹥荒地土壤,3种土样中微生物量碳含量和有机碳含量的正相关关系均达到显著水平。在矿化培养试验中,荒地土壤在培养后28 d微生物量碳含量达到最大值,而稻田土壤和林地土壤在培养后21 d到达最大值,之后随着试验的进行土壤中微生物量碳含量而减少。3种不同利用方式的土壤在随着培养时间的进行,有机碳的矿化速率出现了下降的趋势;不同利用方式土壤的有机碳矿化量与培养前土壤微生物量呈极显著正相关。

The relationship of soil organic carbon and mineralization to themicrobial biomass content (MBC) under the conditions of different utilization types with soil

In this study, we analyzed the relationship between soil microbial biomass carbon content and organic carbon mineralization by collecting the soil of different utilization types from paddy field, woodland and wasteland in the Dongting Lake area.According to the soil culturing experiment in the laboratory, we drew a conclusion that the microbial biomass carbon content in the three model of soil decreases with the deepening of the soil, while the soil microbial biomass carbon content in the paddy field soil got the highest level and the wasteland soil got the lowest. The positive correlativity between soil microbial biomass carbon content and organic carbon content in the three samples reached the significant level. During the soil mineralization experiments, the microbial biomass carbon content of wasteland soil reached the maximum in the fourth week, while it reached the maximum in the third week for the paddy field soil and woodland soil. Then, the soil microbial biomass carbon content decreased as the experiment progressed in.Meanwhile, the mineralization rate of organic carbon in the three different utilization types of soil appeared a downward trend during the experiment, which showed a significant positive correlation between the quantity of soil organic carbon mineralization and the quantity of microbe in uncultured soil.