Did you know that one horse produces approximately 45 pounds of manure per day? That means that in a year's time, you are looking at one heck of a manure pile.
It is environmentally responsible to plan for the disposal of manure from your horses. Manure should be kept 100 feet from wetlands or natural water sources and should be managed so it does not become a detriment to the environment.
You should develop a plan to deal with the manure. Many landscapers or nurseries will haul away the manure for free. Local gardeners also like to use manure, but composting your manure will make it more usuable for everyone.
Manure is fairly low in nutrients, but can provide valuable organic matter to fields and gardens. It can help the soil retain moisture during drought conditions and increases the porosity of the soil facilitating proper infiltration of moisture.
In order to compost manure, it needs to be stacked for about six months to kill the parasite eggs and weed seeds it may contain. The pile should be kept damp and should be turned often if the pile is more than 2 feet deep. The turning will help to allow oxygen in to help the beneficial bacteria do its job.
Manure should only be used on plants after they are actively growing. If you spread manure when soil is frozen or full of water or when plants are dormant, the nutrients will just run off.