Composting is a natural biological process, carried out under controlled conditions, which converts organic material into a stable humus-like product called compost. During the composting process, various microorganisms, including bacteria and fungi, break down organic material into simpler substances. Composting is an aerobic process, meaning that the microorganisms require oxygen to do their work.
At home composting has the potential to manage all of the organic material in the waste stream which cannot otherwise be recycled. Some examples of organic material that can be composted include food scraps, leaves and yard wastes, agricultural crop residues, and paper products. It is not good to compost meat products or leftovers because it can encourage wild animals to try and eat it out of your composter.
There are many residential backyard and electronic composters that can be used for at home composting.
A number of factors are important in controlling the composting process and the time that the process takes. These factors include temperature, moisture, oxygen, particle size, the carbon-to-nitrogen ratio of the waste and the degree of mixing or turning involved. In general, the more actively these factors are controlled, the faster the process.
The length of the process also depends on the degree of decomposition desired in the finished product. Typically, an immature compost can be produced in about a month, while a mature compost may be allowed to cure for six months to a year.
What is the best location for a backyard composter?
The composter should be placed in a well drained area and where it is convenient to use. It should be placed where it can get as much sun as possible as the microbiological activity will work faster.
Yes, you can compost year-round. As the temperature falls, microbial activity decreases but it starts up again as soon as the weather warms up. To make room for your winter organics, empty the finished compost from your unit in the fall. You may also want to move the unit to a more accessible location for the winter. Also, organics can be collected in a covered container stored just outside the back door. In the spring, the collected organics can be added to your composter. Kitchen wastes are high in nitrogen so you need to add lots of leaves or something rich in carbon to be sure that you have the right carbon-to-nitrogen ratio needed for the microorganisms to be most effective.
In some cases, such as in the composting of grass clippings, the raw material may be too dense to allow for the proper flow of air or may be too moist. A common solution to this problem is to add a bulking agent, such as wood chips, to provide structure to material and to allow for proper air flow. The amount of bulking agent required is usually determined based on experience. Some facilities add commercial fertilizers to their composting process, but this can usually be avoided by combining different waste streams together in a specific "recipe". Inoculating the material with microbes is not normally required, since most wastes naturally contain the microbes needed for successful composting to occur.
Any waste management facility, including a composting site, has the potential to generate offensive odours or to attract pests. However, experience at hundreds of composting facilities has shown that proper design and operational procedures can prevent or control these problems. Excessive or offensive odours are generally a sign that the composting process is not proceeding properly, usually because of inadequate aeration or excessive moisture. Close monitoring of these factors can usually help to minimize odours. Facilities can employ abatement systems, such as biofilters, to treat occasional odours. Preventing odours and ensuring that the site is kept clean will ensure that the site does not attract rodents or other pests.
Compost can contain varying amounts of nutrients such as nitrogen, phosphorus and potassium. However, the concentrations of these nutrients in compost are usually lower than those found in common fertilizers.
Compost is more properly described as a soil amendment or soil conditioner which returns valuable organic material to the soil. In addition, compost does benefit the soil by improving soil structure, aeration and water retention.
The Compost Council of Canada serves as the central resource and network for the organics recycling and compost industry, working with its members to advance the recovery and recycling of organic residuals for the production of compost for improved soil health and vitality. For more information, please visit www.compost.org or call 1-877-571-GROW(4769).