Mud isn't a problem as long as the corral has high spots where the horse can go to get out of it. Most horses won't stand in mud or water if they have a choice. The problem with filling in the low spots is that, unless you can install a drainage system to direct the water away from the corral, you have insured the entire pen will be wet/muddy instead of only the low spot. Another problem with filling in the low spots is that horses tend to follow set routes to feeders/waterers and will tromp out those areas over and over again.Low spot in the corrals with mud. I would hate for my 13 yo new horse to get into it during wet seasons. Can't close it off or put hay down because I wouldn't want him to eat it. Any suggestions? I'm sure he wouldn't like dirty hooves. South kansas
This idea is a very SHORT term fix, since the fill used is organic materials. Organic things, bedding, straw, are made to continue breaking down until gone. Mixing that stuff with wet dirt is never going to make location dry out. In that breakdown process, mixture will turn the muddy spot into a BIG mudhole, never get it dried out. Probably will be even more slippery than regular mud in the paddock.If it were my mudhole - I would put down a layer of straw to soak up some of the moisture and provide a base layer; then start putting everything I cleaned out of his stall into the hole to raise the elevation or bring in more dirt from elsewhere.
Similar to the geotech fabric suggestion above.