Mitigation of phosphorus losses from agricultural land with focus on applications of organic fertilisers and use of catch crops

A scientific evaluation of the impact of long-term loadings of organic manures on phosphorus leaching from the topsoil and its possible mitigation by cultivating catch crops.

Testable hypotheses:

• Long-term and frequent loadings of slurry cause higher phosphorus leaching from the topsoil compared to application of mineral fertilisers.
• Long-term and frequent loadings of green manure cause higher phosphorus leaching from the topsoil compared to application of mineral fertilisers.
• Crops with high ability to take up P and have low loss of P after freezing-thawing may act as catch crops for P under climatic conditions typical of central Sweden.
• Crops with high ability to store P in their roots in winter and have low loss of P after freezingthawing may act as catch crops for P under climatic conditions typical of central Sweden.