赣南红壤坡面不同措施径流泥沙及氮磷污染输出试验研究

选择赣南于都县左马小流域的典型红壤坡面,通过在研究区布设标准径流小区,进行了不同措施径流泥沙及氮磷污染输出的试验研究。通过径流小区的试验观测分析表明:水保林+水平竹节沟式综合水保措施实施初期,平均减流和减沙效果达到近73%,以植被增加地表覆盖度,以水平竹节沟坡面水保工程截短坡长,分段拦蓄径流泥沙,可实现保水保土目的;经果林+坡面工程或绿篱是坡地经济果业开发保持水土的重要措施,工程措施在初期发挥作用较绿篱更大;氮磷等面源污染随水土流失从坡面输出,试验区不同措施氮素输出多以径流携带为主,磷素输出均以泥沙携带为主;经果林+工程措施对径流携带氮磷拦截率较高,水保林+工程措施对泥沙携带氮磷的拦截率较高,都在75%以上。

Experimental study on runoff sediment nitrogen and phosphorus pollution output under different measures in red soil slope of the south of Jiangxi

The experiment of runoff sediment nitrogen and phosphorus pollution output is proceed through setting standard runoff plots taking the typical red soil slope in Zuoma Basin of Yudu County located in the south of Jiangxi for example. It shows that the average runoff and sediment decreases nearly 73% in the early stage of water conservation forest and bamboo-type contour trench measures, which could achieve the goal of soil and water conservation by increasing the surface coverage with vegetation, shortening slope length with bamboo-type contour trench and runoff sediment dammed-up. Both fruit forest and slope project and hedges are all important measures for water and soil conservation under economic fruit forest industry development, however, the project plays a more important role in the conservation than hedges in the early stage. The non-point resource pollu- tants such as nitrogen and phosphorous are outputted from slope with water loss and soil erosion, nitrogen output is carried mainly by runoff, however, phosphorous output is by sediment. The interception rate of nitrogen output carried by runoff is higher under the measure of economical fruit forest combined with project, however, the rate of nitrogen output carried by sediment is higher under the measure of water conservation forest combined with project. Both of them are more than 75%.