Spread it over the lawn. You'll be returning the fertilizer you used BACK to the soil so that it can be recycled into more ....grass. Your husband might consider leaving the clippings where he cuts them; a very good practice as long as the lawn is mowed often enough so that it doesn't look like a hay field, lol.

Composted grass clippings can be used just like and along with any compost. Nutrient rich, such compost is a benefit to any soil. That is, unless a lot of herbicides have been used.