两种水稻土磷素渗漏流失及其与Olsen磷的关系  

Phosphorus Move Down by Leaching and Related to Olsen-P of Surface Soil in Two Paddy Soils

作　　者：李卫正[1] 王改萍[1] 张焕朝[1] 曹志洪[2] 艾畅[3] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037 [2]中国科学院南京土壤研究所,江苏南京210008 [3]国家林业局森林资源监督管理办公室,北京100714

出　　处：《南京林业大学学报（自然科学版）》2007年第3期52-56,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家自然科学基金资助项目(40171056);国家重点基础研究发展计划资助项目(G1999011806)

摘　　要：采用田间试验的方法，研究了太湖地区两种水稻土（爽水型水稻土和囊水型水稻土）稻季磷素向下渗漏流失情况及其与土壤Olsen—P浓度的关系。结果表明：在每季度30kg／hm^2常规施磷处理水平下，两种水稻土土壤渗漏水的溶解态磷（Dissolved P，简称DP）平均浓度均远超过了水体富营养化的阈值（O．02mg／L）。施磷处理能显著增加30cm深度渗漏水磷浓度。土壤磷素渗漏迁移流失的主要形态是颗粒态磷（Particulate P，简称PP）。爽水型水稻土和囊水型水稻土各处理土壤渗漏水PP／TP的平均值分别为70．9%和67．0％。囊水型水稻土稻季的磷素渗漏流失量约为每季度469．7g／hm^2大于安镇爽水型水稻土378．5g／hm^2。爽水型水稻土和囊水型水稻土土壤渗漏水中磷浓度各存在一个突变点（Change—point），两者分别为33．0mg／kg和26．3mg／kg。即当爽水型水稻土和囊水型水稻土土壤（0～10cm）中的Olsen—P浓度分别大干33．0mg／kg和26．3mg／kg时，土壤30cm深度的渗漏水磷浓度将随着Olsen—P浓度的增加迅速增大。两种水稻土突变点的差异可能与它们的有机质和黏粒含量不同有关。A field plot experiment was conducted to study phosphorus move down by leaching and its relation to the concentration of Olsen - P in surface soil on two types of paddy soils （the permeable paddy soil in the Anzhen site and the waterlogged paddy soil in the Changshu site） in the Taihu Lake region. Commercial NPK compound fertilizer and single superphos- phate fertilizer were applied to furnish 0,30,75,150,300 kg/hm^2 applied P per season. The results showed that all the Dissolved P （DP） concentrations in leachate samples were much greater than the threshold of 0.02 mg/L caused the eutrophication. Fertilizer P rate had an effect on P concentrations in the leachate. The dominant form of P in the leachate was the Particulate P （PP）. The average value for PP/TP in the leachate from the various P treatments on the permeable paddy soil and the waterlogged paddy soil was 70.9% and 67.0%, respectively. Under the normal P application rate of 30 kg/hm^2 each season, the P losses by leaching at 30cm depth in the Changshu site was 469.7 g/hm^2 , and greater than 378.5 g/hm^2 in the Anzhen site. The change-point of phosphorus by leaching was 33.0 mg/kg in the permeable paddy, higher than in the waterlogged paddy soil （26.3 mg/kg）. This difference was probably associated with the different contents of organic matter and soil clay particle of twopaddy soils, and indicating that P loss by leaching in the waterlogged paddy soil would be easier than that in the permeable paddy soil.

关 键 词：水稻土 溶解态磷 渗漏流失 富营养化 

分 类 号：S714[农业科学—林学]