作　　者： ; ; ; ;

机构地区： 南京农业大学资源与环境科学学院

出　　处： 《应用生态学报》 2004年第6期1025-1029,共5页

摘　　要： 水溶性有机物 (DOM )是有机物质中最为活跃的组成部分 ,在陆地生态系统物质的迁移转化过程中起重要作用 .通过田间试验和室内理化分析证明了DOM在土壤剖面迁移过程中存在明显的“分馏”现象 ,随着土层深度的增加 ,对照、施化肥和施污泥处理土壤DOM的浓度分别由 1 4 5 8、1 1 7 7和 1 1 4 8mg·kg-1 降到 2 1 5 7、2 3 2 3和 1 3 78mg·kg-1 ;不施肥和施化肥处理的土壤DOM随着深度的增加 ,极性物质所占的比例分别由 1 9 0 1 %和 1 8 4 7%增至 34 97%与 4 4 37% ,呈上升趋势 ,而非极性组分所占比例相应降低 ;施污泥处理则出现相反的规律 ,极性组分由 36 96 %降到 1 7 0 7% ,非极性组分由 6 3 0 4 %增为82 93% .土壤DOM的生物降解率由上到下对照和施化肥处理分别由 2 4 38%和 2 4 0 0 %增大到 5 4 74 %和 5 3 81 % ,而施污泥处理的变化规律则相反 ,由 5 3 1 9%降到 30 75 % .DOM的生物降解率与DOM中极性物质的含量呈正相关关系 . Dissolved organic matter (DOM) is the most active component of organic matters,and plays an important role in the translocation and transformation of pollutants and nutrients in terrestrial ecosystem.In this paper,the vertical fractionation of DOM in a yellow brown soil under water dry cultivation was investigated by field experiment and physico chemical analyses.The results showed that in treatments CK,chemical fertilizer and sewage sludge,the DOM concentration decreased from 145.8,117.7 and 114.8 mg·kg -1 to 21.57,23.23 and 13.78 mg·kg -1 with soil depth,respectively.In control and fertilizer treated soils,the hydrophilic fraction of DOM was increased respectively from 19.01% and 18.47% to 34.97% and 44.37% with soil depth,and the biodegradable rate of DOM also increased with soil depth.In sludge treated soil,a reverse tendency was found for the concentration of hydrophilic DOM and its biodegradable rate.Hydrophilic fraction decreased from 36.96% to 17.07%,the increase of hydrophobic fraction was from 63.04% to 82.93%,and the biodegradable rate decreased from 53.19% to 30.75% with soil depth.The biodegradable rate of DOM was positively correlated to the hydrophilic fraction of DOM,and UV spectra analysis also suggested this.

关 键 词： 水旱轮作 土壤水溶性有机物 亲水性 生物降解 纵向分馏

领　　域： [环境科学与工程]