Composting, or biological decomposition, of organic materials is a way to reuse organic waste by converting it to a useful soil amendment or planting medium for your yard or garden. Although the process requires a careful balance of nitrogen rich and carbon rich materials along with air and water, it is a simple process that occurs naturally, just as leaves return to the ground and decay, providing rich nutrients to new plants. Not only does composting provide a rich addition to your garden, it benefits the environment by reducing the amount of organic waste that is sent to landfills.
A compost heap is composed of two main ingredients: green materials, which are nitrogen rich, and brown materials, which have more carbon. Added to the green and brown materials are bulking agents, such as wood chips, and water. Some examples of green materials include food waste, such as fruit and vegetable remnants, and yard waste, like grass clippings. Brown materials include wood chips and dried leaves. Other common additions to a compost heap include coffee grounds, eggshells, dryer lint, newspaper, tea bags, and manure. Since household waste can make up a significant proportion of total waste (23%, for example, of total US waste), using these materials for composting reduces what is sent to landfills. Meat, fish, fats, diseased plants, dairy products, coal, pet waste and chemically treated yard trimmings are not recommended for use in composting because they can contaminate the soil.
The materials should be added in a variety of sizes to facilitate a good mix and allow air and moisture to circulate throughout the pile. Once the materials have been added, the pile should be watered. Water helps mix the substances, and carry the nutrients throughout the pile. Oxygen is also required for composting — the pile gets air through aeration, or turning. Turning the pile should be done regularly, but not so much that the pile dries out. Temperature is another requirement for proper composting — compost heaps should reach temperatures of 140° F (60° C) to allow for proper microbial action. If the compost pile is too wet, doesn’t have enough oxygen, and doesn’t get hot enough, it runs the risk of simply rotting.
There are many benefits of composting. Gardeners may reduce their need for chemical fertilizers, which is beneficial if they are opting for an organic method of gardening. Plants thrive with the addition of rich compost, and the incidence of disease and pests are reduced due to the high temperatures associated with composting. It is also an inexpensive way to fertilize your plants — nearly all of the required materials can be found in the average household.
In addition to the common household process of composting, there are several other methods used for composting larger quantities, and for commercial production. Vermicomposting utilizes red worms, which eat organic matter, then after three to four months, these worms excrete nutrient rich castings. Windrow Composting utilizes large piles four to eight feet (1.2 – 2.4 m) high and 14 to 16 feet (4.2 – 4.8 m) wide. An aerated static pile is made up of a larger pile, usually over pipes which help aerate the piles. In-Vessel Composting, on the other hand, utilizes special vessels to compost materials. These vessels can add water, turn and aerate the materials as needed, providing for a controlled environment to compost large quantities of materials.
For the homeowner who wants to try composting himself, there are few materials and tools required. Once you have gathered up the materials to compost, a pitchfork, shovel and hose should be all that you need. You can simply make a compost pile, or purchase or build a simple bin that will contain the pile while allowing air and moisture to circulate. Begin by spreading six inches (15.24 cm) of brown material, then three inches (7.62 cm) of green material. Add a small amount of soil or compost on top. After lightly mixing the layers, add another three inches of brown material, then water. Turn the pile about once a week, and within one to four months, you should have rich compost.
Written by O. Wallace
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