If you own  horses I am sure you have heard over and over again that the best thing you can do is turn them out on pasture…that is if you have good pasture. Unless your horses are in Kentucky or Ocala Florida the majority of us need to face the fact that we have less than perfect pastures. Sure, they might be lush and green but they will have both pros and cons regarding soil, water, vegetation  and bedrock. If you raise horses, remember the top layer of the ground could play a role in whether your foal reaches it’s optimum performance capabilities. One Canadian race horse breeder who tested his soil discovered that in the first fifteen months of life his foals weren’t receiving the right calcium and phosphorus levels to grow strong bones. After he began supplementing for this soil deficiency, he found his horse started winning on the track. Agronomists recommend taking soil tests every four years (on hayed land , every two) . the tendency for most of us (like my husband ) is to fertilize but many times that investment doesn’t all end up back in the grass. So it might be more cost efficient to add needed supplements to our horses feed to counter balance soil imbalances. A good resource for to determine the soil quality of pastures is the county extension service. They will be able to recommend testing labs or soil consultants.