Cow manure contains many nutrients essential for healthy soil. These include nitrogen, potassium, calcium, magnesium, zinc and sulfur. Adding manure to a garden will help improve water retention as well. Although the manure may be smelly when first applied, the odor will soon dissipate. Apply the manure to the garden several months in advance because it takes some time for it to break down.
Calculate the size of your garden and estimate how much cow manure you'll need. About 450 pounds for every 1,000 square feet of garden space is a good rule of thumb.
Buy the manure, in 20-pound bags, at a garden store. Purchase it from a local farmer if you need an excessive amount. Plan to spread the manure in the fall just after all crops have been harvested.
Attach your manure spreader to your lawn tractor. Look at the tires of the spreader to make sure they are in good condition and will be able to handle a full load. Add air to the tires if needed.
Load the cow manure into the spreader by opening the plastic bags and dumping the manure into the spreader. If you have a bulk amount, you can load the manure into the spreader with a shovel. Fill the spreader to within about 6 inches from the top.
Drive to the end of the garden. Stop your garden tractor and engage the parking brake. Get off of your tractor and push the lever on the back of the spreader to release the manure. Return to your tractor and drive down the rows.
Drive over your garden area at medium speed, allowing the manure to cover the ground to a thickness of 1/2 inch to 1 inch. Refill the manure spreader as needed, remembering to push the lever on the spreader to the "off" position so it doesn't disperse while you are reloading.
Use the garden tiller to mix the manure into the soil. Wear gloves and heavy shoes when doing this. Move slowly with the tiller and overlap each row about 6 inches. Inspect the garden and run the tiller over spots where the manure is not mixed well with the soil.
Add a light layer of leaves, pine straw or hay to the newly tilled soil. Spray water very lightly with a garden hose. Allow your mulched soil to cure during the next few months and you will be ready for spring planting.