浙南易蚀土壤的团聚体稳定性及其稳定机理  

Stability and It's Mechanism of Aggregates in Easily Eroded Soils Derived from Purple Rock in the South of Zhejiang Province

作　　者：王虹艳[1] 吴士文[2] 马海洋[2] 郭军玲[1] 卢升高[1] 

机构地区：[1]浙江大学环境与资源学院,浙江杭州310029 [2]河南农业大学资源与环境学院,河南郑州450053

出　　处：《土壤通报》2010年第2期429-433,共5页Chinese Journal of Soil Science

基　　金：浙江省科技计划项目(2007C23057)资助

摘　　要：土壤团聚体的数量和稳定性是衡量土壤质量和可蚀性的重要指标。应用常规湿筛法和Le Bissonnais法测定了紫砂岩母质发育的柑橘园土壤团聚体稳定性,分析了土壤团聚体稳定性与胶结物质组成的关系。结果表明,供试土壤团聚体稳定性差异较大,湿筛法测定的水稳性团聚体MWD在0.75～3.49mm,MWD干筛-湿筛为0.15～2.89mm;Le Bissonnais法测定的水稳性团聚体平均MWD为1.57～3.12mm,其平均MWD与湿筛法测定的>0.25mm团聚体含量、MWD、5～2mm团聚体破坏率和MWD干筛-湿筛呈极显著相关,表明两种方法测定的结果具有可比性;5～2mm土壤团聚体经快速湿润(FW)、慢速湿润(SW)和预湿后扰动(WS)3种处理后,团聚体崩解产物的MWD表现为FW<SW<WS,团聚体崩解产物的粒级分布随处理方式不同而不同,经快速湿润处理后,大多数团聚体崩解,崩解成较小粒径的水稳性团聚体,表明崩解的主要机制是由于团聚体内部的闭塞空气产生的压力引起的;土壤团聚体的稳定性指标与黏粒和游离氧化铁含量呈显著正相关,而有机质主要影响水稳定性团聚体的数量,它与土壤中MWD呈极显著正相关。Soil aggregate stability is a crucial index affecting soil quality and erodibility.Aggregate stability of orange garden soils derived from purple rock was measured by applying wetting sieving method and Le Bissonnais method,and the relationship between aggregate stability and soil cementing matter（organic carbon,clay and free Fe oxides content） was also assessed.Results indicated that aggregate stability varied greatly among soils.The mean weight diameter（MWD） ranged from 0.75 mm to 3.49 mm and MWDdry-wet values from 0.15 mm to 2.89 mm.The mean MWDs for three treatments developed by Le Bissonnais ranged from 1.57 mm to 3.12 mm.There were highly significant correlation between MWD values of three treatments developed by Le Bissonnais and 0.25 mm water-stable aggregate content,MWD and percentage aggregate disruption determined by wet-sieving method,suggesting that aggregate stability defined by Le Bissonnais method is well comparable with the routine Yoder method.The MWD of three treatments（fast wetting,slow wetting and stirring after pre-wetting） measured on 5-2 mm aggregate had the following order：FWSWWS.The MWDs for the fast wetting test showed the lowest values for each soil,which indicating the aggregates to be very unstable for the fast wetting treatment.It was in accordance with results of the resulting aggregate size distribution after treatment.These results indicated that the mechanisms of aggregate breakdown were in the order of slakingmicro-crackingmechanical breakdown.The aggregate stability was significantly correlated with clay and free iron oxide contents.However,soil organic matter mainly affected the amount of water-stable aggregate in soils,which highly related to the MWD.

关 键 词：紫砂岩 团聚体稳定性 湿筛法 LE Bissonnais法 

分 类 号：S152.4[农业科学—土壤学]