To provide free nitrogen fertilizer pulled from the air.
That is a really exciting answer for the red clover, but I have more questions. Why are the farms in oregon doing this? Can farms in any geographic area plant red clover? Why are the flowers red but the leaves green? Do I have a similar red clover growing in my yard, that is just red clover leaves with small purple flowers?
Thanks, I looked up the other plant I was thinking of and it's called purple shamrock, it does not provide nitrogen fixing. It looks like the red clover is pretty widely grown across the US from your link.