摘要
以东北黑土区32对自然和耕作黑土为研究对象,对比研究了两种土壤水稳性团聚体及其结合碳的分布特征.结果表明:自然土壤0~30cm水稳性大团聚体(>0.25mm)质量分数及其结合碳均高于微团聚体;随着土层深度的增加,大团聚体及其结合碳逐渐降低,而微团聚体(<0.25mm)及其结合碳显著增加(P<0.01).耕作土壤团聚体分布特征与自然土壤相反,与自然土壤相比,耕作土壤大团聚体数量及其结合碳急剧降低,且>1mm的大团聚体降低幅度远大于其他粒级团聚体.自然土壤大团聚体质量分数与土壤有机碳(SOC)存在明显的正相关关系(P<0.01),尤其是>1mm大团聚体;耕作土壤>1mm大团聚体质量分数与土壤总SOC相关不显著;自然与耕作土壤总SOC与各级团聚体结合碳呈极显著正相关(P<0.01).与自然土壤相比,耕作土壤大团聚体结合碳明显降低,而微团聚体结合碳增加了37.1%,总SOC含量下降了29.5%,表明大团聚体在总SOC变化中起主要作用.水稳性大团聚体对管理措施响应迅速,可以作为评价农业管理措施转变对土壤肥力和土壤质量影响的指标.
The study on the distribution characters of water-stable aggregates and aggregate-associated C in 32 pairs of virgin and cultivated black soils in Northeast China showed that in virgin soils, the amount of water-stable macroaggregates ( 〉 0. 25 mm) and their associated C in 0-30 cm layer were higher than those of microaggreagtes ( 〈 0. 25 mm). With the increase of soil depth, the amount of macroaggregates and their associated C showed a decreasing trend, while those of microaggregates increased significantly (P 〈 0. 01 ). The distribution characters of aggregates in cultivated soils were in adverse to virgin soils. Compared with those in virgin soils, the amount of macroaggregates and their associated C in 0-30 cm layer in cultivated soils declined drastically, particularly for 〉 1 mm aggregates. In virgin soils, the proportions of soil macroaggregates, especially for 〉 1 mm aggregates, were positively correlated to soil organic carbon; but in cultivated soils, no obvious relationship was observed between them. The associated C of soil aggregates was positively correlated to soil total organic carbon in both virgin and cultivated soils (P 〈0. 01 ). In cultivated soils, less C was associated with macroaggregates but 37% more C was associated with microaggreagtes, and the total soil organic carbon was decreased by 29. 5%, in comparison with those in virgin soils, which suggested that soil macroaggregates played an important role in the dynamics changes of soil total organic carbon. It was indicated that soil water-stable macroaggregates were sensitive to soil management, and could be an indicator in evaluating the impacts of agronomic managements on soil fertility and soil quality.
出处
《应用生态学报》
CAS
CSCD
北大核心
2008年第5期1052-1057,共6页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(40471125)
吉林省科技发展计划项目(20050206-4)
国家科技支撑资助项目(2006BAD15B01)
关键词
水稳性团聚体
团聚体结合碳
大团聚体
黑土
water-stable aggregate
aggregate-associated C, macroaggregate
black soil.