Abstract

Sources of inorganic and organic N leaching from grass-clover mixtures at field sites in Denmark, Germany and Iceland were investigated. Grass or clover was labelled with 15N-urea four times (autumn 2007, spring, summer and autumn 2008) prior to the leaching season in autumn and winter 2008. Soil water was sampled at 30 cm depth and analyzed for 15Nenrichment of dissolved inorganic N (DIN) and dissolved organic N (DON). Most 15N was recovered in DON for both labelled grass and clover at all sites. At the Danish site, grass and clover contributed more to the DON pool than the DIN whereas the opposite was observed at the German and Icelandic sites. The results show that both clover and grass contribute directly to N leaching from the root zone in mixtures, and that clover contribution is higher than grass. Furthermore, the present study indicates that roots active in the growth season prior to the drainage period contribute more to N leaching than roots active in the growth season the previous year, which is consistent with estimates of root longevity at the three sites.

Keywords

DIN; DON; clover; grass; leaching

Published in

Grassland Science in Europe
2010, Volume: 15, pages: 1028-1030
Book title: Grassland in a changing world
ISBN: 978-3-86944-021-7
Publisher: European Grassland Federatio

Conference

23th General meeting of the European Grassland Federation

SLU Authors

• Rasmussen, Jim

  • Aarhus University

• Frankow-Lindberg, Bodil

  • Department of Crop Production Ecology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science


Permanent link to this page (URI)

https://res.slu.se/id/publ/30528