Fånggrödor i Norra Östersjöns vattendistrikt

Abstract: 70 % of the lakes and waters in the water district of northern Baltic Sea do not reach the requirements for good ecological status. This is mostly due to eutrophication caused by a too high deliverance of nutrients from agricultural land or effluents. Losses of particulate phosphorus through water erosion contribute to a great extent to this eutrophication. In the action plan for the water district cover crops are mentioned as a measure for reducing losses of phosphorus from arable land. This paper reviews the possible effect of cover crops in the water district and discusses what crop that would be most suitable. Since the biggest losses of particulate phosphorus occur during late autumn and early spring, cover crops would preferable be left over the winter and not broken until spring. The most suitable crops are forage radish or oil-seed radish since they die due to freezing during winter and therefore not complicate or delay spring tillage the following year. The cover crops not only help to protect the soil surface, they also lead to an improved soil structure, break up compacted soil and reduce the pressure from weeds and diseases.