Hi. I recently moved and improved my coop and run to a shadier spot. The summers here have been really hot. However we have recently had a lot of rain and I realised there's a lot of clay in the soil. It makes it slippery for me, and rock hard for the chickens once it has dried. In gardening terms, the best way to break up clay is to add gypsum & organic matter (compost, straw etc). I know the chickens would love the straw, but don't know if the gypsum is a good idea. I also have a large supply of composted cow manure. Is this a good or bad idea to spread it in the run? Any other ideas?