I wouldn't be sure that is clover? I don't think they have such a big indentation at the end of the leaf and there is a paler line running across the leaf, there are some three hundred trefoils, plants with clover like leaves, I have at least three growing as weeds in my garden, not counting red and white clovers in the lawn. They are all legumes, so arguably they probably produce a bit of nitrogen, but I would think that what they take easily outweighs what they give, get it gone.