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以广东省内第四纪红色黏土、玄武岩和花岗岩母质发育的土壤为研究对象,采集不同土地利用方式(水田、旱地、林地、果园/草地)下表层(0~15 cm)和亚表层(15~30 cm)土壤,研究土壤有机碳及其组分(腐殖质碳、易氧化有机碳)、土壤团聚体及其稳定性,分析土壤有机碳及其组分与土壤团聚体及其稳定性之间的相互关系。结果表明:土地利用类型、成土母质等影响土壤有机碳及其组分。3种母质发育的土壤中,各腐殖质组分占有机碳的比例是胡敏酸碳(HAC)<富里酸碳(FAC)<胡敏素碳(HMC),第四纪红色黏土母质发育土壤腐殖酸碳(HAC+FAC)以草地最高、水田最低;玄武岩、花岗岩母质发育土壤腐殖酸碳以果园最高。土壤中易氧化有机碳所占比例均高于惰性态,第四纪红色黏土母质发育土壤易氧化有机碳占有机碳比例以草地最高、旱地最低;玄武岩、花岗岩为果园最高、林地最低。3种母质发育土壤团聚体(湿筛)主要以<0.25 mm微团聚体为主,表层土壤>0.25 mm团聚体所占比例、团聚体平均重量直径(MWD)、团聚体破坏率(PAD)大于亚表层。土壤有机碳各组分均随着有机碳质量分数的增加而增加,>0.25 mm团聚体质量分数和团聚体MWD随着土壤有机碳及其组分质量分数的增加而增大;PAD随着土壤易氧化碳组分质量分数增加而降低,易氧化有机碳组分有利于土壤中形成较大的团聚体,并增加团聚体水稳性。
Taking Quaternary red clay, basalts and granite parent materials in Guangdong Province as the research objects, the surface layer (0-15 cm) and subsurface (15-15 cm) of different land use types (paddy field, dry land, woodland, orchard / grassland) ~ 30 cm) soils, soil organic carbon and its components (humus carbon, organic carbon easily oxidized), soil aggregates and their stability were studied, and the relationships between soil organic carbon and its components and soil aggregates and its stability were analyzed The relationship between. The results showed that the types of soil and soil parent material affected the soil organic carbon and its components. In the soils with three parent materials, the ratio of humic components to organic carbon was HAC, FAC, HMC and Quaternary red clay parent soil. Carbon (HAC + FAC) has the highest grassland and lowest paddy field; basalts and granite parental soil have the highest humus carbon content in the orchard. The proportion of readily oxidizable organic carbon in soil was higher than that in inert state. Quaternary red clay parent soil had the highest ratio of organic carbon to organic carbon, the highest in grassland and the lowest in dry land. The basalt and granite were the highest in orchard and the lowest in woodland. Soil aggregates (wet sieves) of three parental species were mainly dominated by <0.25 mm microaggregates with surface soil> 0.25 mm aggregates, aggregates with an average weight diameter (MWD) and aggregates destruction rate (PAD) greater than Sub-surface. Soil organic carbon components increased with the increase of organic carbon mass fraction,> 0.25 mm aggregates mass fraction and aggregates MWD increased with the mass fraction of soil organic carbon and its components increased; PAD with the soil The mass fraction of easily oxidizable carbon increases and decreases, and the readily oxidized organic carbon component is conducive to the formation of larger aggregates in the soil and increases the water stability of the aggregates.