摘要
选取我国东部江淮丘陵地区典型小流域——六叉河流域为实验区,以流域主要土地利用类型——旱地土壤为研究对象,原位监测了作物整个生长期中,不同磷肥条件下,磷在旱地壤中流中水平空间差异、时间动态与土壤垂直差异上的动态迁移规律。结果发现:在雨量丰沛、地下水位接近地表且土壤水分饱和度高的六叉河流域,旱地壤中流流量丰富且流量变化与降雨分布具有高度的一致性和同步反应性。在0.5和1m深处,壤中流中总磷(TP)浓度的平均值分别为0.566和0.269mg·L-1,远远超出相邻水体(巢湖)中磷浓度的控制要求。在水平空间、垂直剖面以及时间动态上,不同磷肥处理条件下壤中流中磷的迁移量没有显著性差异(P<0.05),说明与磷肥处理水平不相关。壤中流中TP和PO4-P浓度同降雨特征(降雨量/频率)密切相关,雨期浓度低,而干旱期则相对较高。监测证实,在六叉河流域,由于土壤表层(0～1m)中的磷含量较高,丰富的降雨-壤中流过程极易推动土壤磷传输。因此,除了地表径流传输控制外,如何有效抑制壤中流中的磷迁移对该区域水环境污染的治理十分关键。
An experiment was conducted on a farmland in Liuchahe watershed, a typical agricultural watershed located on the north bank of Chaohu Lake （one of the most eutrophic lake in East China）, to study the phosphorus movement in topsoil （0-1 m depth） with different phosphate treatment level. The results showed that due to high annual precipitation and groundwater level near ground, subsurface flow of the farmland topsoil in Liuchahe watershed was very plentiful, but the flow volumes changed quickly with daily precipitation intensity/process. The average concentrations of total phosphorus （TP） in the subsurface flow were： 0.566 mg·L^-1 （0.5 m） and 0.269 mg·L^-1 （1 m）, respectively. TP and PO4-P concentrations between treatments were no significance （P〈0.05）, and responded quickly with the precipitation conditions. The results suggested that due to long agricultural practices and a lot of fertilize used in recent years, the P-pollutants fate in the subsurface flow was not affected by the content of phosphorus in the topsoil but rainfall process in this region. Thus, besides the surface runoff, how to control P-transport in the subsurface flow may be another important way for increasing the water quality of Chaohu Lake.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2005年第6期1132-1138,共7页
Journal of Agro-Environment Science
基金
国家重点基础研究发展规划项目(2002CB412308)
基金项目(40171003)
关键词
旱地土壤
非点源污染
磷
溶质迁移
壤中流
farmland soil
nonpoint source pollution
phosphorus
solute transport
subsurface flow
