Nitrogen Fixation in Agriculture: Forage Legumes in Sweden as an Example

Perennial grasslands, managed for forage production and leys, represent the majority of cultivated land in Sweden. In northern Sweden, the leys are typically comprised of the grasses timothy, Phleum pratense, and meadow fescue, Festuca pratensis, together with red clover, Trifolium pratense. It is common to establish the leys as an undersowing in barley and then keep them for about 3 years in a crop rotation. Leys are normally harvested twice per year for silage, but some leys are also grazed.