A one thousand pound horse produces approximately fifty pounds of manure per day or about ten tons per year.  In addition, from six to ten gallons of urine is produced which when soaked up by bedding can constitute another fifty pounds daily.  Therefore, four horses in stalls can produce 160,000 pounds of manure and wet bedding per year.  That is a mountain of manure by anyone's standards.

 EQUIPMENT FOR MANURE MANAGEMENT

    Manure spreaders are wagons with mechanical apparatus designed to distribute manure as the tractor is driven through a pasture or field.  Spreaders are either friction-drive or powered by the Power Take Off of a tractor.  The smaller, older spreaders are friction-driven; the bigger, newer spreaders are made for a PTO.

     Friction-drive spreaders are ground driven, the power for the mechanics of the spreader is generated by the tires rolling on the ground.  Therefore, this type of spreader can be operated behind a pick-up or a team of horses as it is a self-unloader.  There are two levers, one to control the speed of the apron chain which moves the load toward the rear of the spreader and the other to control the beater bar at the back of the spreader which flings the manure into the air.  Spreaders powered by a PTO are usually bigger, heavy-duty spreaders which much be operated by a large tractor.

     Harrows are useful for smoothing manure into an arena or track after discing, and for breaking up and spreading manure on pastures.  There are basically three types of harrows, or drags as they are sometimes called:  the chain (or English), the spike tooth, and the spring tooth.  The English harrow and the spike tooth harrow are the most suitable drags for manure management.  The English harrow is made of heavy bars that criss-cross each other in a diamond-shaped configuration and have protrusions called teeth on the bottom side.  They are very heavy and expensive but do a wonderful job of leveling manure in a pasture as well as aerating the soil without ripping it up.  Home-made drags, simulating the English style, have been made with chain link fence, but the lack of teeth and their light weight make them bounce on top of the soil so result in little smoothing and leveling.  English harrows are difficult to load and when you move them by dragging behind the tractor, they work everything in the tractor's path.
 The spike tooth harrow has prongs (teeth) attached to a series of bars which can be rotated by levers.  In this way the teeth of the spike tooth harrow are adjustable for work or transport.  The teeth can be set in a flat position to move the harrow, in a slightly elevated position to break manure clumps, and straight up to dig into the earth.

   In dry sunny climates, harrowing is a good practice as it exposes the parasite eggs in the manure to the sun which kills them. In humid climates, however, it is felt that harrowing the manure in pastures just spreads the parasite eggs over a larger area while still allowing them to be viable, so in effect increases a horse's chances of reinfestation. In such a situation, regularly collecting manure would be best.