Topics : Species and Forage Variety Trials : Species Fact Sheets : Birdsfoot Trefoil
Species: Birdsfoot Trefoil
Additional birdsfoot trefoil information via the Forage Information System (FIS)
Birdsfoot Trefoil Fertility
Although trefoil seedings will nodulate and fix nitrogen in soil with a pH as low as 4.5, maximum nodulation occurs at pH 6.0 to 6.5. Lime should be applied to low pH soils as recommended by a soil test.
Trefoil will produce better than alfalfa on poor soils, but its fertility requirement for high yields are similar to those for alfalfa. Fertilizer applications at establishment should be based on a soil test. In the absence of a soil test, assuming a medium- fertility soil, plow down 0-45-135 lb per acre and apply 20-60-20 lb per acre in the row at seeding (banded if possible). When fertilizer recommendation exceed this amount, the fertilizer should be incorporated into the seedbed prior to planting.
Soil testing is the best guide for determining fertilizer requirements of established stands of trefoil. When the trefoil makes up more than 30 percent of a mixed trefoil and grass stand, no N fertilizer should be needed. However, if trefoil makes up less than 30% of the mixture, up to 50 lb N per acre will be needed to meet the grass demand for N and to maximize production. Nitrogen fertilization of a trefoil stand with fertilizer N or manure will reduce the N fixing ability of trefoil and increase the competitiveness of the grass or weeds that also may be in the stand.
Additional and more detailed information on forage fertilization is also available.