The Science of Composting
The basic principle of composting is that it mimics the natural decomposition of organic material in a controlled setting faster than it would occur in nature. The result is a substance containing nitrogen, phosphorous, potash, trace minerals and carbon that were part of the make up of the original material. Once mixed into soil, these nutrients will release slowly as the new growth occurs. Essentially, compost feeds the microbial element of the soil and in the process, nutrients are released for plant use. Finally, the most resistant carbon elements help provide tilth to the soil which improves soil structure.
The process of composting requires proper amounts of air and water, ideal temperature and an array of various microbes. There are a few approaches to composting: aerobic (with air), anaerobic (without air), accelerated or slowly, contained or piled. All approaches will work, it is a matter of evaluating your purpose for composting in the first place. If you live in an area where you intend to have a garden of some kind, be it flower or vegetable, then you may have the space to create an aerobic, layered system using small wooden stakes and some chicken wire fencing. If your intention is to simply reduce your “trash” output then a small, anaerobic, contained tumbler system would be sufficient. Within either system, you want to maintain a balance between moisture, temperature, nitrogen and ammonia. Ultimately, it should not an offensive odor but more of an “earthy” aroma. If you do have an odor problem then you need to back off on the moisture level by adding dry elements such as grass clippings, dry leaves or shredded newspaper. This will not only absorb the moisture but will help eliminate to odor.
You want to be sure to avoid adding any meat products into your compost until your compost is well established and you fully understand the balance you need to maintain, otherwise the compost will become infested with undesirable insects and excessive nitrogen. Its best to stick with vegetable scraps, coffee grounds, egg shells and grains mixed with other organic matter such as grass clippings, hay or straw, leaves and shredded newspaper.