Institute of Agricultural Environment and Sustainable Development, Chinese Academy of Agricultural Sciences/Key Laboratory of Agricultural Environment, Ministry of Agriculture, Beijing 100081, China.
Agro-Environmental Scientific Observation and Experiment Station of Yueyang, Ministry of Agriculture, Yueyang 414000, Hunan, China.
Ying Yong Sheng Tai Xue Bao. 2021 Feb;32(2):564-570. doi: 10.13287/j.1001-9332.202102.023.
To explore the mechanism of exogenous organic materials enhancing soil organic carbon and soil fertility, based on a long-term experiment located in Hengyang Red Soil Experimental Station, we examined the effects of winter green manure and straw returning patterns (CK, winter fallow; MV, winter Chinese milk vetch; S, early-season rice straw total returning; DS, early-season and late-season rice straw total returning; SMV, winter Chinese milk vetch + early-season rice straw total returning; DSMV, winter Chinese milk vetch + early-season and late-season rice straw total returning) on soil aggregates and organic functional groups. The results showed that the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) in double cropping rice soil was the highest with a ratio of about 72.1%-81.8%, and the organic carbon content in the two kinds of aggregates was as high as 12.1-20.7 g·kg, accounting for 22.7%-59.0% of the total organic carbon. The main organic functional group in paddy soil was polysaccharides, followed by aliphatic carbon and aromatic carbon. The abundance of all those groups was affected by winter Chinese milk vetch growing and straw returning. Compared with other treatments, DSMV significantly increased the proportion of super aggregates (>2 mm) and macroaggregates (0.25-2 mm) and favored the accumulation of inert carbon such as aromatic carbon in the two kinds of aggregates. DSMV could enhance the stability of soil aggregates and organic matter, which had high potential in the real agricultural production.
为探索外源有机物料提升土壤有机碳及土壤肥力的机制，本研究基于衡阳红壤实验站长期试验，分析了冬季绿肥及秸秆还田模式（CK，冬季休闲；MV，冬季紫云英；S，早稻秸秆全量还田；DS，早、晚稻秸秆全量还田；SMV，冬季紫云英+早稻秸秆全量还田；DSMV，冬季紫云英+早、晚稻秸秆全量还田）对土壤团聚体及有机功能基团的影响。结果表明，双季稻土中超团聚体（>2mm）和大团聚体（0.25-2mm）的比例最高，约为 72.1%-81.8%，且二者有机碳含量高达 12.1-20.7g·kg-1，占总有机碳的 22.7%-59.0%。稻田土壤中主要的有机功能基团为多糖类，其次为脂肪族碳和芳香族碳。这些功能基团的丰度受冬季紫云英生长和秸秆还田的影响。与其他处理相比，DSMV 显著增加了超团聚体（>2mm）和大团聚体（0.25-2mm）的比例，有利于芳香族碳等惰性碳在这两种团聚体中的积累。DSMV 可增强土壤团聚体和有机质的稳定性，在实际农业生产中具有较高的应用潜力。
