【摘要】 农田中磷素的流失是水体富营养化的重要原因之一,而胶体又是磷素从土壤向河流等水体转移的重要形式,因此,阻止胶体磷从土壤向水体流失对控制水体富营养化至关重要。本研究通过动态土柱法测定胶体磷在水稻土、菜地土与茶园土中的阻滞系数,从而研究不同质地土壤对胶体磷流失的影响,并通过向土壤中加入不同量(0%、0.05%和0.1%)的聚丙烯酰胺(polyacrylamide, PAM)研究其对胶体磷的阻控效果。结果表明:在未施加PAM的对照组中,砂粒含量最高的菜地土对胶体磷的阻滞效果最小,阻滞系数只有6.397,而砂粒含量最少的稻田土对胶体磷的阻控效果最佳,阻滞系数为9.915;实验组与对照组相比,在菜地土、茶园土和稻田土3种供试土壤中分别施加0.05%和0.1%的PAM后,土壤对胶体磷的阻滞系数分别增大了58.3%、46.8%、26.5%和87.7%、67.1%、60.4%。这表明PAM可以显著增加土壤对胶体磷的阻滞系数,具有显著的胶体磷阻控效果。更多还原

【Abstract】 Loss of phosphorus in farmland is an important cause of eutrophication in water environment, and colloids are an important form of phosphorus transported from soils to rivers and other water bodies. Therefore, it is very important to control the loss of colloidal phosphorus in soil. In this study, a dynamic soil column method was used to determine the retardation coefficient of colloidal phosphorus migration in paddy soil, vegetable soil and tea soil, and the control effect of colloidal phosphorus migration was studied by applying different levels(0%, 0.05% and 0.1%) of polyacrylamide(PAM). The results showed that in the control group without PAM,vegetable soil with the highest sand content had the lowest retarding effect against colloidal phosphorus migration, and the retardation coefficient(Rd) was 6.397; and the control effect of paddy soil with the smallest sand content against colloidal phosphorus migration was optimal(R_d=9.915). Compared with the control group,after applying 0.05% and 0.1% PAM in the three tested soils(vegetable soil, tea soil, paddy soil), the retardation coefficient of soil colloidal phosphorus increased by 58.3%, 46.8%, 26.5% and 87.7%, 67.1%, 60.4%, respectively,indicating that the application of PAM can significantly increase the control effect of soil against colloidal phosphorus migration and reduce the risk of colloidal phosphorus loss.更多还原