研究了2种垦殖方式对三江平原小叶章湿地表土团聚体及其有机碳分布的影响.结果表明,垦殖后,粒径〉0.25mm的大团聚体呈降低趋势,大豆田中0.053~0.25mm微团聚体增加;水稻田中主要增加的是〈0.053mm微团聚体.垦殖降低了各粒级团聚体有机碳含量,在0~10cm和10~20cm土层中,〉1mm及0.053~0.25mm团聚体有机碳含量降幅均呈现大豆田大于水稻田,〈0.053mm团聚体与之相反;而0.25~1mm团聚体有机碳含量在0~10cm土层水稻田中降幅大,10~20cm土层大豆田降幅大.0~20cm全土和〈0.25mm微团聚体有机碳储量分别为:小叶章湿地〉水稻田〉大豆田,小叶章湿地〉大豆田〉水稻田.水稻田比大豆田土壤有机碳储量稍高,但其微团聚体有机碳储量及其占土壤有机碳储量的比例低于大豆田,开垦为大豆田比开垦为水稻田有利于土壤有机碳长期存留.
How reclamation of Calamagrostis angustifolia wetland for soybean and rice farming impacts the SOC distribution of aggregates in the topsoil was investigated.A declining trend of macro-aggregates(0.25mm) but increasing of micro-aggregates of 0.053~0.25mm in the soybean field and 0.053mm in the paddy field was observed.Wetland reclamation reduced SOC content of aggregates.At soil layers of both 0~10 cm and 10~20cm,the SOC content of 1mm and 0.053~0.25mm aggregates were lost more in soybean field than in paddy field,but opposite conclusion for 0.053mm aggregates.The larger drop of SOC content of 0.25~1mm aggregates took place in the top 10 cm topsoil in paddy field and 10~20cm layer in soybean field.The overall soil's SOC storage was ordered from high to low as Calamagrostis angustifolia wetlandpaddy fieldsoybean field while the SOC storage of micro-aggregates(0.25mm) as alamagrostis angustifolia wetlandsoybean fieldpaddy field.Compared with soybean field,paddy field contained slightly higher SOC but both the SOC storage of micro-aggregates(0.25mm) in paddy field and its share in total soil SOC were lower.Therefore,after reclamation,soybean farming was more friendly for sustainable SOC residence in the soils than rice farming.