中国高潜水位沉陷区采煤废弃物复垦农田的土壤特征

摘要

为了研究充填介质对中国东部高潜水位采煤塌陷区复垦土壤特征的影响，对采用煤矸石或粉煤灰作为充填介质形成的复垦土壤化学和微生物指标进行分析。结果表明，充填介质粉煤灰的存在能显著提高复垦土壤中pH值和含水率；在0~10 cm、10~20 cm、20~50 cm土壤层，采用粉煤灰形成的复垦土壤 MBC、MBN、MBC/TOC的比率高于采用煤矸石形成的复垦土壤；采用煤矸石作为充填介质形成的复垦土壤中，重金属As和Cr含量、土壤微生物碳氮比、呼吸熵等高于对照土壤和粉煤灰充填形成的复垦土壤；主成分分析表明，充填土壤中重金属含量、土壤微生物量和土壤酶活性能代表大部分复垦土壤特征。%Reclaimed mining-induced subsidence area soils (RMSs) could restore soil quality and crop productivity in coal mining area. This study was conducted to evaluate the effects of mineral-processing wastes (fly ash vs coal gangue) as backfill substrates on soil chemical and microbial properties in mining-induced subsidence area. A general higher water holding capacity (WHC) and pH had been observed in fly ash than coal gangue reconstructed soil. Soil microbial biomass C (MBC) and N (MBN), MBC/TOC (total organic carbon) ratio (qmic) were higher under the influence of the fly ash, while contents of As, Cr, C/Nbio, the basal respiration per unit of microbial biomass (QCO2) were higher under the coal gangue reconstructed mode in 0-10, 10-20, 20-50 cm layers. The microbial basal respiration was higher in 0-10, 10-20, 0-50 cm layers, while was lower in 20-50 cm layer under fly ash than that of coal gangue reconstructed mode. The lower QCO2 of fly ash mine soil suggested the lower maintenance energy requirement of the microbial community. Moreover, the contents of metals may possibly have negative implications for soil microbial and enzyme activities in reconstructed soil.