红壤坡耕地地表径流和壤中流中可溶性有机碳的迁移特征

(1.江西师范大学 地理与环境学院, 南昌 330022; 2.江西省水土保持科学研究院, 南昌 330029; 3.江西省土壤侵蚀与防治重点实验室, 南昌 330029; 4.江西农业大学 园林与艺术学院, 南昌 330045)

可溶性有机碳; 红壤坡耕地; 壤中流; 地表径流

Characteristics of Migration of Dissolved Organic Carbon in Overland Flow and Interflow in Red Soil Sloping Field
YU Xiaofang1,2, XIAO Shengsheng2,3, XU Mingze2,4, ZHANG Jie2,3, FANG Huanying2,4

(1.School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China; 2.Jiangxi Institute of Soil and Water Conservation, Nanchang 330029, China; 3.Jiangxi Provincial Key Laboratory of Soil Erosion and Prevention, Nanchang 330029, China; 4.College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China)

dissolved organic carbon/DOC; red soil sloping fields; interflow; surface runoff

备注

为了阐明南方红壤区坡耕地坡面产流产沙及DOC随地表径流和不同层次壤中流的迁移特征,探讨壤中流和地表径流对碳素运移损失的贡献比,以红壤坡耕地野外径流小区为研究对象,通过模拟降雨试验,研究了次降雨条件下坡面产流产沙及DOC随地表径流和不同层次壤中流的迁移特征。结果 表明:(1)产流产沙方面,径流以地表径流为主,占到总径流量的(95.86%); 壤中流占径流比例较小(4.14%),且以深层壤中流输出形式为主,即60 cm壤中流(3.71%)>30 cm壤中流(0.43%); 次降雨过程中产沙量先随径流量增加而增加,达到峰值后缓慢减小。(2)尽管壤中流中DOC的质量浓度显著高于地表径流,DOC迁移总量还是以地表径流为主,大小关系为地表径流(98.16%)>60 cm壤中流(1.64%)>30 cm壤中流(0.30%)。相关结果将有助于加深碳循环与土壤侵蚀相互关系的认识,对从源头控制红壤坡耕地土壤碳素流失、维持土壤质量也具有一定的实践意义。

In order to clarify the characteristics of runoff and sediment production on the sloping farmland in the southern red soil region and the characteristics of migration dissolved organic carbon(DOC)with surface runoff and interflow in soil layers, and discuss the contribution ratio of interflow and surface runoff to carbon transport loss. Taking runoff plots in red soil slope farmland field as research sites, the characteristics of runoff and sediment yield and migration of DOC with surface runoff and interflow in different of soil layers under the rainfall conditions were studied through simulated rainfall experiment. The results showed that:(1)in terms of runoff and sediment yield, runoff was dominated by surface runoff, accounting for 95.86% of interflow accounted for 4.14% of the total runoff, and was in the form of flow in deep soil, interflow at 60 cm depth(3.71%)was greater than that(0.43%)at 30 cm depth; the amount of sediment production increased with the increase of runoff during the individual rainfall event, and decreased slowly after reaching the peak value;(2)although the DOC concentration in interflow was significantly higher than that in the surface runoff, the total DOC migration flux in surface runoff was dominant, DOC migration flux decreased in the order: surface runoff(98.16%)> interflow at 60 cm depth(1.64%)>interflow at 30 cm depth(0.30%). These results will help to deepen the understanding of the relationship between carbon cycle and soil erosion, and have practical significance for controlling carbon loss from the source and maintaining soil quality in red soil sloping fields.