施玉米秸秆生物质炭对土壤腐殖质组成和结构特征的影响

Effects of Applying Corn Straw Biochar on Composition and Structural Characteristics of Soil Humus

生物质炭是黑碳的一部分,与腐殖质碳同为土壤有机碳慢库的组成部分,对土壤固碳、土壤肥力和环境解毒有重要作用。通过培养试验研究了土壤添加玉米秸秆生物质碳360 d后对土壤腐殖质组成及其结构特征的影响。结果表明:土壤添加生物质炭后,土壤有机碳和胡敏素含量随生物质炭用量的增加而增加,胡敏酸及富里酸含量随生物质炭用量增加而降低,可提取腐殖质中胡敏酸的比例差异不显著。施用生物质炭使土壤胡敏酸的色调系数下降、相对色度提高,H与C物质的量比和O与C物质的量比降低,高温放热与中温放热比值和高温失重与中温失重比值上升,施用生物质炭促使黑土胡敏酸的分子缩合度升高,氧化度下降,热稳定性提高,使胡敏酸分子结构复杂化,有利于土壤有机碳的稳定。

Biochar (Bc), as part of the black carbon (BC)(collectively referred to as BC when not distinguished) and part of the slow pool of soil organic carbon (SOC) with humus carbon (HC), plays an important role in soil detoxification, soil fertility and environment detoxification. For this reason, the effects of the addition of artificially prepared corn straw biochar on soil humus composition and its structural characteristics after 360 days of culture experiments were studied. The results showed that after adding Bc in soil the content of SOC and Hu increased with the increase of Bc dosage, the content of HA and FA decreased with the increase of dosage, and PQ difference in the proportion of HA in extractable humus was not significant. The addition of Bc decreased ΔlgK of soil HA, increased RF, decreased H/C molar ratio and O/C molar ratio, and increased the ratio of high temperature exothermic and moderate temperature exothermic and the ratio of high temperature weight loss and intermediate temperature weight loss, indicating that the application of Bc promoted the molecular condensation degree of black soil HA, lowered oxidation degree and enhanced thermal stability, which is beneficial to the stabilization of SOC.