One of my clover plots(my first one about 4yrs old) seems to have too much nitrogen build up which is causing grass to choke out the clover. I've sprayed with roundup and am thinking about discing and seeding with black oil sunflowers to utilize the nitrogen from the clover before reseeding this fall with clover. Do bees use sunflower nectar/pollen? The other alternative is grain sorghum, and I know bees cannot use it. I might also mix a little brassicas into the clover this fall to use up any nitrogen left over so my clover gets a good head start on the grasses.