Are horse paddocks threatening water quality through excess loading of nutrients?. (1st January 2015)

• Record Type: Journal Article
• Authors: Parvage, Mohammed Masud; Ulén, Barbro; Kirchmann, Holger
• Is Part Of: Journal of environmental management. Volume 147(2015)
• Page Start: 306
• Page End: 313
• Publication Date: 2015-01-01
• Subjects: Animal grazing -- Eutrophication -- Horse keeping -- Nitrogen and phosphorus -- Nutrient losses; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2014.09.019
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The Baltic Sea is one of the most eutrophied water bodies in northern Europe and more than 50% of its total anthropogenic waterborne phosphorus (P) and nitrogen (N) loads derive from agricultural sources. Sweden is the second largest contributor of waterborne N and the third largest contributor of waterborne P to the Baltic Sea. Horse farms now occupy almost 10% of Swedish agricultural land, but are not well investigated with regard to their environmental impact. In this study, potential P, N and carbon (C) leaching losses were measured from two representative horse paddock topsoils (0–20 cm; a clay and a loamy sand) following simulated rainfall events in the laboratory. Results showed that the leachate concentrations and net release of P, N and dissolved organic C (DOC) from paddock topsoils were highest in feeding and excretion areas and considerably higher from the loamy sand than the clay paddock topsoil. Leaching losses of dissolved reactive P (DRP) were significantly ( p < 0.05) correlated with concentrations of water-soluble P and ammonium acetate lactate-extractable P (P-AL) in the soil, while leaching losses of dissolved organic P and total organic N were significantly correlated with DOC concentration in leachate. Leaching loads of P and N from paddock topsoils greatly exceeded average figures for Swedish agricultural topsoils. It was concluded that: i) horse paddocks pose a potential threat to water quality via leaching of excess P and N, ii) feeding and excretion areas are potential hotspots for highly enhanced leaching losses, and iii) paddocks established on sandy soils are particularly susceptible to high N leaching losses. Highlights: Leaching losses of nutrients to waters from horse paddocks is an ignored problem. Rain simulation experiments demonstrated a high potential for such losses. Potential phosphorus leaching was up to 3 times higher than from a reference area. Potential nitrogen leaching was up to 15 times higher than from a reference area.