不同复垦年限煤矸山重构土壤有机碳及其组分差异

土壤有机碳含量是土壤肥力状况的重要标志之一,其活性组分对田间管理措施反映敏感。因此,分析煤矸山复垦重构土壤有机碳含量及其组分差异对于揭示土壤碳库变化、指导复垦地田间管理措施的实施有重要意义。本研究以山西省霍州曹村煤矸山复垦后5a(R-5a)、7a(R-7a)和9a(R-9a)的果园为对象,通过与当地原地貌果园(CK)对比,分析了3种复垦样地土壤总有机碳(TOC)及其组分可溶性有机碳(DOC)、微生物生物量碳(MBC)、轻组有机碳(LFOC)和重组有机碳(HFOC)的差异,以及与土壤环境因子间的关系。结果表明:①随复垦年限的增加,3种复垦样地土壤TOC、LFOC和HFOC含量均呈先增后减趋势,DOC含量呈增加趋势,MBC含量呈先减后增趋势;但与CK相比,3种复垦样地土壤TOC、DOC、MBC、LFOC和HFOC含量均明显偏低。②DOC/TOC和MBC/TOC在R-7a样地中最低,LFOC/TOC随复垦年限的增加呈增加趋势,HFOC/TOC呈减少趋势,表明土壤中更多的有机碳从稳定态转变为活性态。③土壤全氮、全磷、碱解氮、碳氮比、黏粒含量、pH和含水量均不同程度影响有机碳含量,其中全氮、全磷、黏粒含量和土壤pH为关键因子。

Characteristics of Soil Organic Carbon and Its Components in Coal Waste Piles Reclaimed with Different Years

Soil organic carbon (SOC) content is one of important indicators of soil fertility, and its active components are sensitive to field management measures. Therefore, it is of great significance to analyze the characteristics of SOC and its components in the reclaimed coal waste piles to reveal the changes of soil carbon pool and guide the implementation of field management measures in the reclamation area. With the reclaimed piles of 5a (R-5a),7a (R-7a) and 9a (R-9a) in Caocun village in Huozhou City of Shanxi Province as the study objects and the local original orchard as CK, the paper analyzed the differences in soil total organic carbon (TOC) and its components of dissolved organic carbon (DOC), microbial biomass carbon (MBC), light carbon organic (LFOC) and heavy organic carbon (HFOC) in three kinds of reclaimed plots, and their relationships with other soil properties were also explored. The results showed that: 1) with the increase of reclamation year, TOC, LFOC and HFOC increased initially and then decreased in the three reclamation plots, DOC increased, and MBC decreased initially and then increased. However, the contents of TOC, DOC, MBC, LFOC and HFOC in the three reclaimed plots were significantly lower than those of CK. 2) DOC/TOC and MBC/TOC were the lowest in the R-7a plot. LFOC/TOC increased with the increase of reclamation year, while HFOC/TOC decreased, indicating that more organic carbon in soil changed from stable state to active state. 3) TN, TP, AN, C/N, clay content, pH value and SWC were all correlated with organic carbon content, among which TN, TP, clay content and pH value were the key factors.