I have red clover that grows naturally on my land in Portage county. It is part of the seed bank and pops up on it's own. One year when I had a thick coating of paper mill sludge dumped on a fallow 12 acre full sun flat field in the middle of the summer, the red clover came up through the sludge in huge amounts. I had done nothing but mowed the field in preparation for the sludge dumping. The paper mill sludge must have smothered any weeds that wanted to come up, but had just the right properties in it to get the red clover to germinate.
I have 15 foot wide fire break / driving lane that goes around the entire perimeter of my 12.5 prairie restoration. I have been planting RR ag and Eagle soy beans on it for the past two years so that I can get good weed control. Next fall after a spring controlled burn I plan on putting in clover on this area. There will definitely be a good amount if not all of red clover in my planting mix.