Projects on the nitrogen cycle and balance examine nitrogen inputs, biological fixation, use by crops, offtake, transformations in the soil and losses by leaching, surface runoff and emissions to the air. While the emphasis here is on projects that examine the role of legumes in the nitrogen economy of agriculture, large scale, integrative projects on the wider nitrogen cycle are also included.
Click a link in the list below to move down the page for a brief description of each project and web link.
Forage legumes in multi-species grassland
Summary of PhD thesis by Karin Pirhofer-Walzl
The aims of the study, at Copenhagen University, were to quantify the performance of multi-species grassland mixtures comprising grasses, legumes and herbs in terms of three nutrient processes: mineral accumulation, nitrogen transfer and nitrogen uptake. Legumes included Medicago sativa, Trifolium repens, Trifolium pratense and Lotus corniculatus. Three field experiments were conducted in Denmark using 15N methodology to trace nitrogen through the plant-soil system and to measure N2 fixation. The role of legumes in importing nitrogen to the community is highlighted. The downloadable files below are a project summary on the Legume Futures template (Word) and a pdf file of the summary and contents pages from the thesis. Contact the author for access to the thesis.
Contact: karin.pirhofer@gmail.com
Word file, 41 kb: Project information
PDF file, 921 kb: Project summary and contents
First published on this site: 5 December 2012.
NitroEurope
The nitrogen cycle and its influence on the European greenhouse gas balance
NitroEurope is a five year EU-funded project, 2006-2011, that considers the nitrogen cycle and its particular contribution to greenhouse gas emissions. The scope of the project is therefore is very much wider than legumes, but contributes to the biophysical baseline against which legume cropping systems may be assessed. The project produced the NitroEurope brochure "The nitrogen cycle and its influence on the european greenhouse gas balance" which is available online from the web site (link below). The project contributed substantially to the recently published European Nitrogen Assessment (Cambridge University Press, 2011, edited by M. Sutton et al. ) which is a comprehensive account of the N cycle in a wide range of systems (cover above right). The web site also gives links to the Edinburgh Declaration on Reactive Nitrogen - a statement (arising from a recent major conference) which contains the following statement "an overall strategy to reduce the losses and adverse impacts of reactive nitrogen on society should be focussed on improving nitrogen use efficiency, particularly in agriculture, which can provide significant financial benefits to farmers and society as a whole." NitroEurope is also entered on this site as a network under General information.
Web link: NitroEurope
