草原退化对土壤有机矿质复合体中结合态腐殖质影响

草原退化引起的土壤性质的变化会影响腐殖质与矿质颗粒的结合状态 ,本文对采自草原退化前后的土壤样品分级提取不同粒径的土壤有机矿质复合体 ,然后用不同的浸提剂提取复合体中结合状态不同的腐殖质 ,对其含量、分布和组成在草原退化前后的变化进行了分析 ,得出了土壤各粒级复合体中腐殖质主要以松、紧结合态形式存在 ,并且主要集中在粘粒和粉粒级复合体中 ;草原退化时土壤腐殖质的减少主要是粘粒细粉粒级复合体 ,其次是粗粉粒级复合体中松态腐殖质减少的贡献 ;而松态腐殖质的减少又主要是 HA的减少等结论

Enfluence of Grassland Degradation on Conbined Humus in Soil Organo-Mineral Conmplexes

Soil properties changes caused by grassland degradation can influence combining form of humus and mineral particles. Soil organo-mineral complexes were separated from steppe soils sampled before and after grassland degradation using fractional method of particle size and density, and humus of different combined forms were extracted from these complexes,then variations of humus content, distribution and composition were analyzed respectively.Results showed that most of humus of soil organo-mineral complexes composed of loosely and tightly combined forms, and they enriched in clay and silt complexes;while grassland degradationthe decrease of soil humus firstly resulted in the reduction of clay and fine silt complexes,secondly coarse silt complexes; and the decrease of loosely combined hnmus mainly resulted from HA reduction.