Animal manure is a natural fertiliser because it is rich in nitrogen. However, it can't be used fresh because it contains materials harmful for growing plants. The composting process removes the harmful material from the manure. Animal manure compost is best used to grow the type of plants the animal is fed on. Pig manure is good for root crops such as leeks and potatoes.
Composting requires a ratio of carbon organic matter to nitrogen (C:N) measured in pounds. The ratio for pig manure is 6:1 or 6 pounds of organic matter to 1 pound of manure. Creating a compost pile using pig manure requires physical labour but is worth it for harvesting healthy crops.
Locate a spot for the compost pile. Compost piles generally do best in the shade but not too close to trees. The roots of some trees are attracted to the compost and roots grown into the pile if it's kept too close.
Create a drainage system for the compost pile by digging a trench with a shovel. The trench goes across the middle of the base. Cover it with stiff hardware fabric.
Cover the base of the composting area with a thin layer of twigs to assist with drainage.
Add the first layer of organic material 6 to 8 inches deep. The University of Missouri Extension Service suggests such materials as "sod, grass clippings, leaves, hay, straw, weeds, manure, chopped corncobs, cornstalks, sawdust, shredded newspaper, wood ashes, hedge clippings and many kinds of plant refuse from the garden."
Moisten the organic layer with water.
Add a layer of pig manure. Remember the C:N ratio for pig manure is 6:1. The layer of organic matter will be 6 times heavier than the layer of pig manure. This nitrogen layer is about 1 inch thick. Moisten with water.
Put a 1 inch soil layer on top of the pig manure and moisten with water.
Continue this rotation process until the pile is about 3 to 5 feet high. Remember to moisten each layer with water as you go.
Leave this pile for a few weeks and mix it together periodically. Keep it moist continually.
Let the pile decompose for 4 to 6 months before using it in the garden. During this time you can add more layers to the top but each new layer takes the same amount of time to make humus. Only remove and use the layers that are ready.
Build the compost pile in a location that is a convenient distance to the garden and a water source.