Raw material quantity and composition

In the homeplace are many sources of raw materials for the compost pile. From the kitchen comes coffee and tea grounds, and vegetable and fruit trimmings, which amount to 0.2 to 0.9 pound (90 to 400 g) per capita per day. From the landscape comes leaves, grass clippings, brush trimmings, old plant material, and many weeds, yard trimmings that represent 15 to 20% of the municipal waste stream. Leaves present less of a challenge in both collection and composting than do other organic sources while representing a major portion of the waste stream. In most cases the home compost pile will be built with landscape trimmings and rakings. Starting with leaves and grass clippings, for example, and adding some brush or wood chips for a bulking agent could prove to be the right mix to begin composting in the first year. Kitchen wastes can be added to the pile as they occur .

Most all organic materials will compost, but not all of them should be put in the pile. Some organic wastes will attract rodents, dogs and cats, while weeds and pathogen-infected materials may survive the composting process. Also, fatty foods and bones should be avoided because they will attract rodents and create odor problems. Cat and dog fecal materials as well as cat litter should not be used in the pile due to harmful pathogens.

In looking at compostable materials one consideration should be the amount of time each material needs for breakdown. High nitrogen materials, like grass, will break down very readily while wood chips may take up to two years to reach the humus stage. The higher or wider the carbon:nitrogen ratio (C:N), the longer time it will take for breakdown to occur. Coarse materials, such as straw, nut shells, corncobs and stalks, will also take longer to breakdown. However, the greener and more succulent the material, the
quicker the breakdown period. All materials that are high carbon should be cut or shredded into small pieces and mixed with high nitrogen materials, such as manure or fresh grass clippings.

Do not discount the rough or coarse materials because they can be used as bulking agents in the pile. Coarse matter will break down slowly in the pile and will improve the pile structure by allowing air circulation. A bulking agent is very important when there is not a good mixture of materials or when raw materials tend to pack together.

It might take several attempts to get the right mixture of materials that will give you the perfect recipe for composting. Mixing different types and sizes of organic materials will provide a well- drained and arable compost pile. The more varied the materials going into the pile, the better chance of maintaining the proper C:N ratio and efficient decomposition.