I've come across the related concept, perennial Clover is planted in Orchards to provide a Nitrogen source for the trees. I found a statemtent on there being an 18 month lag before the Clover would start to release Nitrogen for the trees to use, so its not immediate but will have good long-term effects. People will also grow Clover in lawns for the same reason.
I also will re-iterate the use of organic fertilizers. The Rhizobium bacterium that do the Nitrogen fixing can be sensitive to chemical fertilizers. Using a chemical fertilizer may undo what you are trying to do with the cover crop.