摘要
为揭示暴雨条件下磷素的流失规律,在湖北省香溪河流域选择具有代表性的黄棕壤坡耕地进行原位人工模拟降雨试验,研究磷素随地表径流和壤中流的流失特征。结果显示:次暴雨过程中产生两种径流形式(地表径流和壤中流),地表径流约占总径流的68.4%,壤中流约占31.6%;地表径流和壤中流磷素输出过程差异明显,地表径流中总磷(TP)和颗粒态磷(PP)变化过程较为一致,呈波浪式起伏无明显降低趋势,溶解态总磷(DP)和溶解态无机磷(DIP)在降雨初期浓度较高,之后随降雨持续迅速减小并逐步趋于稳定。壤中流中TP和PP在初期出现浓度峰值(6.44mg·L-1、5.87mg·L-1),之后迅速减小并趋于稳定,DP和DIP则在降雨过程中均无明显变化,各形态磷素的平均浓度均超出水体富营养化的阈值;TP随径流的流失量为0.262kg·hm-2,不同形态的磷素流失均以地表径流为主,贡献率均达72.7%以上,可见土壤对磷素具有较强的滤减作用。地表径流TP流失形态以PP为主,占总量的92.8%,壤中流中PP和DP所占的比例相当,无论在地表径流还是壤中流中,DIP的输出负荷均占DP的78.3%以上。降雨后总磷和速效磷沿剖面的养分含量均明显低于降雨前,表层养分含量的损失量最大,速效磷养分的损失比例比全量损失比例大。
In order to reveal the loss characteristics of non-point phosphorus under storm conditions,a field experiment was conducted on the sloping arable land of typical yellow-brown soils in Xiangxi River watershed,Hubei Province.Artificial rainfall was used to evaluate the phosphorus transfer characters through surface flow and interflow.The results showed two runoff patterns：surface flow and interflow during rainfall process.The surface runoff and interflow accounted for 68.4% and 31.6% respectively in total runoff.The output feature between surface flow and interflow was significantly different.Total phosphorus（TP） and particulate phosphorus（PP） fluctuated and kept consistent in surface flow without obvious downtrend,while Dissolved phosphorus（DP） and dissolved inorganic phosphorus（DIP） were both high at the early stage,then rapidly decreased with time and kept steady finally.TP and PP in interflow were high at the very beginning（6.44 mg·L-1 and 5.87 mg·L-1,respectively） but decreased rapidly and then tended to be stable when artificial rainfall continued.DP and DIP kept relatively stable in the whole runoff process,the average concentration of all forms of phosphorus exceeded the threshold of eutrophication of freshwater.Loss amount of phosphorus carried by runoff was 0.262 kg·hm-2,and surface flow was the main way for all forms of phosphorus loss-all output loadings exceed 72.7%,i.e.,so soil had significant effects on reducing phosphorus output.PP was the primary form of phosphorus loss in surface flow which accounted for 92.8%,PP and DP shared the same level in interflow.No matter in surface flow or interflow,the output of DIP was mainly in the form of DP,which accounted for over 78.3%.After the rainfall,TP and rapidly available phosphorus（RAP） level were both lowered significantly,especially in surface,and the proportion of RAP loss was heavier than that of total loss.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2013年第1期49-55,共7页
Journal of Agro-Environment Science
基金
国家自然科学基金面上项目(51179095
51179205)
国家自然科学基金杰出青年基金(50925932)
国家自然科学基金青年基金(51009080
51009081
51209123)
三峡大学研究生科研创新基金(2011CX009)
关键词
三峡水库
香溪河
磷素
壤中流
流失规律
Three Gorges Reservior
Xiangxi Bay
phosphorus
interflow
loss characteristics
