恢复措施对排土场土壤养分及微生物活性的影响

Effects of restoration measures on soil nutrient and microbial activity in the coalmine dump

以海州露天矿排土场为研究对象,选取工程复垦、人工种植林地(榆树、刺槐和紫穗槐)和天然草地3种恢复措施作为修复地,以荒裸地作为对照,研究恢复措施对土壤养分、土壤呼吸强度、土壤微生物生物量碳和代谢熵的影响,探讨生态恢复措施对排土场土壤质量的改善情况。结果显示:修复地土壤中的全N、全P和全K含量显著高于荒裸地,土壤有机碳则为工程复垦土壤最低。土壤养分随土壤深度的增加而减少。恢复措施能够影响土壤微生物活性,与荒裸地相比,人工修复措施和自然恢复措施能显著降低土壤呼吸强度和qCO2,人工种植林地和天然草地能显著提高SMBC,土壤呼吸强度和SMBC随着土壤深度的增加而减少,qCO2则反之。SMBC和qCO2与土壤养分之间具有显著相关的关系,可以用于评价土壤的肥力水平。对排土场进行种植林地和自然修复可以增加土壤微生物的活性,有利于土壤质量的提高。

Engineering reclamation, planted forests （Ulmus pumila, Robinia pseudoacacia and Amorphafruticosa） and natural grassland were selected as restoration land, while bare land was used as control in Haizhou opencast coalmine dump. In order to find out the best restoration measure, the influences of ecological restoration measures on soil environment, soil respiration, soil microbial biomass C and metabolic quotient were studied in coalmine dump. The results showed that soil total N, total P and total K were more in restoration land than in bare land. Soil organic carbon was the lowest in engineering reclamation land. Soil nutrition decreased with the depth of soil increasing. Restoration measures could affect soil microbial activities. Artificial and natural restoration measures could reduce soil basal respiration rate and qCO2. Soil microbial biomass C was higher in planted forests and natural grassland than other restoration measures. Soil basal respiration rate and soil microbial biomass C decreased with the soil depth increasing, while qCO2 increased. Because there was positive significance correlation between soil microbial biomass C, qCO2 and soil nutrient, soil microbial biomass C and qCO2 could assess soil fertilities.