不同秸秆对植烟土壤有机碳矿化和腐殖质组成的影响

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摘  要：針对南方常见的烤烟轮作体系，研究添加不同作物秸秆（烟草、油菜和水稻）后土壤有机碳矿化特征和腐殖物质含量变化，为合理利用烟田废弃物提供理论依据。采用室内恒温培养试验，将3种秸秆分别以覆盖于土壤表层和与土壤混匀2种方式添加，分析不同处理土壤CO₂释放规律、总有机碳（TOC）和腐殖物质含量的变化与相关性。结果表明，以不同方式添加作物秸秆对土壤CO₂释放影响显著，覆盖处理土壤有机碳矿化强度高于混匀处理，达到极显著差异;3种秸秆的添加均能显著提高土壤CO₂释放速率和累积释放量，有机碳矿化强度表现为油菜秸秆>烟草秸秆>水稻秸秆。经过180 d的培养，添加秸秆的各处理土壤TOC、腐殖物质各组分含量和PQ值显著升高。相关性分析表明，土壤CO₂累积释放量与土壤中TOC、HE（可提取腐殖质总量）与FA（富里酸）含量呈显著相关。因此，3种作物秸秆的添加可提高植烟土壤有机碳含量和腐殖化程度，且秸秆混匀处理具有较好的固碳减排效果。

关键词：作物秸秆;植烟土壤;二氧化碳释放;有机碳矿化;腐殖物质

中图分类号：S572.06          文章编号：1007-5119（2019）05-0008-07      DOI：10.13496/j.issn.1007-5119.2019.05.002

Effects of Different Crop Straws on Organic Carbon Mineralization and Humus Composition of Tobacco-Growing Soil

CHEN Lijuan， ZHOU Jiheng^*， LIU Li， ZHANG Yi， LI Qiang， ZHANG Yiyang， CHEN Gui

（Hunan Agricultural University， Changsha 410128， China）

Abstract： In view of the common flue-cured tobacco rotation system in Southern China， the characteristics of soil organic carbon mineralization and changes of humus content after adding different crop straws （tobacco， rape and rice） were studied to provide theoretical basis for rational utilization of tobacco field wastes. Indoor constant temperature incubation experiment was adopted in which three kinds of straw were applied by covering the soil surface or mixing with the soil， and the changes and correlation of CO₂ release pattern， total organic carbon content （TOC） and humus content of soil under different treatments were analyzed. The results showed that the addition of crop straw in different ways had significant influence on soil CO₂ release， and the mineralization intensity of soil organic carbon under the mulching treatment was higher than that under the mixing treatment， reaching an extremely significant difference. The addition of the three kinds of straws can significantly increase the soil CO₂ release rate and cumulative emission amount， and the mineralization intensity of soil organic carbon in each treatment is shown as rape straw > tobacco straw > rice straw. After 180 days of culture， the contents of TOC， humus composition and PQ value of soil treated with straw were significantly increased. Through correlation analysis， it can be found that the cumulative emission of soil CO₂ was significantly correlated with the content of soil TOC， HE （total humus that could be extracted） and FA （fulvic acid）. Therefore， the addition of three crop straws can improve the soil organic carbon content and humus degree， and the straw mixing treatment has a better effect of carbon sequestration and emission reduction.

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