摘要
在滇池流域的设施大棚和露地两种土地利用类型上,选择粉砂质壤土、粘壤土、砂质粘土、壤质粘土等4种典型土壤质地,应用原位模拟人工降雨设备,对地表径流和渗漏的流失过程以及水中的总磷(TP)、水溶性总磷(DTP)和溶解性正磷酸盐(DRP)的浓度、流失量变化特征进行了研究,模拟降雨量为80 mm,雨强采用40 mm/h以模拟渗漏流失过程和120 mm/h以模拟径流流失过程。结果表明:在不同土壤质地下,壤质粘土在两种流失方式下都极易发生养分流失,而砂质土的径流量和渗漏量较高,养分流失风险增加;壤质粘土的TP流失浓度和流失量高,而砂质土的DTP、DRP流失浓度和流失量高;在两种不同流失方式下,径流比渗漏初始产流时间早,产流历时短;而且径流是磷素流失的主要途径,砂质壤土、粘壤土、壤质粘土(露地)径流水中的TP、DTP、DRP流失浓度和流失量要高于渗漏,但砂质粘土和壤质粘土(大棚)的渗漏流失量较高。在不同土地利用方式下,露地比大棚更易发生径流流失,且土壤磷素流失多以泥砂结合态的PP为主要流失形态,而砂质粘土和壤质粘土(大棚)以水溶性总磷(DTP)为磷素流失的主要流失形态;在本研究区域内,土壤速效磷含量已经高达272.38 mg/kg,远远超过了作物适宜生长的土壤速效磷含量,也超过了土壤磷素淋溶的临界值,因此,滇池流域土壤磷素向下淋溶的趋势对地下水的富营养化造成了巨大威胁。
Under two kinds of land-use types of facilities greenhouse and culture in the field of Dianchi watershed,we select four kinds of typical texture of the soil： silty loam,clay loam,sandy clay,loamy clay,use the rainfall simulation equipment in situ,research the process of surface runoff and leach,analyzed for total phosphorus（TP）,dissolved total phosphorous（DTP） and dissolved reactive phosphate（DRP）,and the water losses number change characteristics.Simulated rainfall is 80 mm,and use 40 mm/h rainfall intensity to simulate the leakage process and 120 mm/h to simulate the runoff process.The results showed that runoff and leach are easily take place in the Loamy clay than in other different soil texture,the sandy soil with high runoff and seepage,the nutrient loss risk was increased.And the loss concentration of TP of loamy clay is higher,but the loss concentration of DTP,DRP of sandy soil is higher,too.In different of loss types,the initial leak of runoff is earlier than seepage,and the runoff duration is shorter,and the surface runoff is the primary way for phosphorus loss.The runoff TP,DTP,DRP loss concentration and losses of sandy loam,clay loam,loamy clay（culture） is higher than the seepage,but the sandy clay and loamy clay（greenhouse） leakage is higher.In different of Land-use types,culture is easier to take place runoff than greenhouse,and the major loss forms of soil phosphorus is mud and sand combination patterns of PP,but the sandy clay and loamy clay（greenhouse） major loss forms of soil phosphorus is dissolved Total Phosphorous（DTP）.Within the study area,the soil available phosphorus content is as high as 272.38 mg/kg,far exceeding soil suitable available phosphorus content for crops growth,and exceeded the critical value of soil phosphorus leaching.Therefore,the trend that soil phosphorus is leaching downward caused a tremendous threat for groundwater eutrophication in Dianchi Watershed.
出处
《水土保持学报》
CSCD
北大核心
2010年第3期13-17,共5页
Journal of Soil and Water Conservation
基金
云南省省院省校合作项目(2006YX35)
昆明市科技计划项目(08s010201)
关键词
滇池流域
模拟降雨
土壤质地
磷素流失
Dianchi watershed
simulated rainfall
soil texture
phosphorus loss
