水稻土磷环境敏感临界值的研究  

Environmentally Sensitive Thresholds of Phosphorus of Paddy Soils

作　　者：章明奎[1] 周翠[1] 方利平[1] 

机构地区：[1]浙江大学环境与资源学院资源科学系,浙江杭州310029

出　　处：《农业环境科学学报》2006年第1期170-174,共5页Journal of Agro-Environment Science

基　　金：浙江省科技计划项目(2004C33061)

摘　　要：采用室内测试方法研究了3组质地(粘土、重壤土和轻壤土)水稻土水溶性磷(0.01mol·L-1CaCl2-P)与土壤测试磷(Olsen-P和Bray1-P)及土壤磷饱和度的关系。结果表明,水稻土因淹水耕作,其磷释放潜力明显高于旱地土壤,水溶性磷随土壤测试磷的增加而增加。土壤测试磷及磷的饱和度与土壤水溶性磷的关系存在转折点,当土壤磷超过转折点时,土壤水溶性磷和磷的释放潜力明显增加。在好气条件下,供试水稻土磷环境敏感临界值(转折点)在Olsen-P50～75mg·kg-1、Bray1-P90～140mg·kg-1和磷饱和度21%～23%之间;在厌气条件下,供试水稻土磷环境敏感临界值(转折点)在Olsen-P35～45mg·kg-1、Bray1-P75～115mg·kg-1和磷饱和度16%～18%之间,超过临界值土壤磷素可对环境产生非常明显的负影响,不应再施用磷肥和粪肥。Phosphorus （P） in surface runoff from agricultural soils is a contributor to accelerated eutrophication in surface water. The sustainable management of chemical fertilizer and manure to minimize freshwater eutrophication requires identifeation of soil P levels that exceed crop P requirements and have the potential for P loss. The relationship between water soluble P （0.01 mol·L ^-1 CaCl2 extractable P） and agricultural test P （Olsen-P and Bray 1-P） and phosphorus sorption saturation were researched in three groups of paddy soils with different soil texture. 139 soil samples were analyzed by Olsen P, Bray 1-P and water soluble P in both aerobic and anaerobic conditions. Soil P sorption saturation was calculated as a function of oxalate extractable P, Fe and Al. Thresholds in the relationships between water soluble P and Olsen-P, Bray 1-P and P sorption saturation were identied by segmented linear regression （change point analysis）. The thresholds for Olsen P, Bray 1-P and P sorption saturation for the paddy soils were 50-75 mg·kg^-1, 90-140 mg·kg^-1 and 21%-23% under the aerobic condition, and 35-45 mg·kg^-1, 75-115mg·kg^-1 and 16%-18% under the anaerobic condition, above the thresholds the potential of P release from the paddy soils to water increased, These threshold values may be of environmental importance in estimating the potential of soluble P loss from paddy soil by drainage and leaching.

关 键 词：水稻土 土壤测试磷 磷饱和度 水溶性磷 环境敏感临界值 

分 类 号：X153.6[环境科学与工程—环境科学]