Transport of Phosphate from Soil to Surface Waters by Preferential Flow

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• 作者：Rene Gä ; chter ; John M. Ngatiah ; and Christian Stamm
• 刊名：Environmental Science & Technology
• 出版年：1998
• 出版时间：July 1, 1998
• 年：1998
• 卷：32
• 期：13
• 页码：1865 - 1869
• 全文大小：139K
• 年卷期：v.32,no.13(July 1, 1998)
• ISSN：1520-5851

文摘

Enrichment of lakes with soluble reactive phosphorus(SRP) leads to their deterioration as ecosystems,recreationareas, and drinking water reservoirs. In many cases,fertilized soils are their most important P source.Moststudies dealing with P losses from soils to surface watersconcentrate on erosion and surface runoff. Leachingis mostly considered to be of minor importance. Onthebasis of an in-situ sprinkling experiment with dye andbromide as tracers and of observations of the dynamicsof SRP concentration and water discharge at thewatershed scale, we identify soil macropores andartificialdrainage systems as the most important pathways forthe vertical and lateral transport of SRP from P-enrichedsoil surfaces to surface waters. A conceptional modelexplains why in drainage systems flow rate and SRPconcentration are positively related. We estimatethatmore than half of the yearly SRP load is leached from thesoil, and thus conclude that counter to the conventionalwisdom, in the investigated watershed, leaching and notsurface runoff is the most important mechanism for Ptransfer from soils to surface waters. It should betestedto see whether this conclusion can be generalized andalso hold true for other watersheds with artificiallydrained,P-enriched soils with a low matrix permeability.