Weeds usually cannot compete with good stands of improved forage species that have been provided with lime, fertilizer, and proper grazing management. Good fertility keeps weeds from becoming established but is less effective once they become a problem. Clipping pastures provides some control by preventing weeds from setting seed. If annual weeds are cut below their growing points, most will die. Another alternative control measure is multispecies grazing with sheep, goats, and cattle.
Herbicides can also control some common pasture weeds.
However, herbicides are expensive, and only a few are labeled for use on pastures. To establish legumes into cropland, consider a preplant herbicide, because tillage operations have probably incorporated some weed seed. An alternative is to prepare the seedbed several weeks before planting and allow the weed seeds to germinate and emerge before plowing them under. Try the less expensive, alternative methods first, and use herbicides as a last resort. Legume Selection Planting a solid stand of a legume is not recommended, unless you are planning to sell high-quality pure legume hay.