Making Compost

The process of making compost is very simple, but attention to all the details makes the difference between a true finished compost and a pile of partly decomposed material. The essence of composting is the breakdown of organic materials into a form that is stable and in which the essential nutrients are available to plants.

It begins with an understanding of the nature of the organic materials you are using. A balance must be struck between the amount of carbon in the raw materials and the amount of nitrogen available to the bacteria that break down the carbon.

The more woody the material, the higher the percentage of carbon. Examples of high carbon materials include wood fibre such as sawdust or shredded branches and twigs. Materials with moderate carbon content include things like fall leaves, garden refuse and straw. Examples of low carbon materials include kitchen garbage, grass clippings and green leafy plants.

The low carbon materials will break down quickly with virtually no need for the addition of high nitrogen materials. The more woody the material the more nitrogen you must add to produce a quick breakdown of the materials.

There are many sources of nitrogen rich, (protein rich), material. Some of the best are fresh manure of any kind, animal wastes such as bloodmeal and fishmeal, and high protein foods used for animals such as soymeal, linseed meal, alfalfa meal and cottonseed meal. When you build your pile, mix these materials with your organic material, keeping in mind that the woodier it is the more nitrogen rich materials you need. Water enough to make the material moist but not soggy. Piles need to be at least 1 - 1.3m, (3 -4 ft), high in order to keep the heat that is produced inside the pile. Smaller piles will cool too quickly and will not produce the high heat needed to kill weed seeds and pathogens.

The sides of the pile should be exposed to the air, (oxygen). The addition of small amounts of lime into the soil can be beneficial to gardens that have acidic soils that you wish to sweeten, however do not use large quantities and realize that even without added lime compost is alklaline in nature with a pH of 8.0 or so being common for the finished compost.

Once your pile is built it needs to be turned frequently in order to introduce oxygen into the centre of the pile. As the process of decay commences you will feel the heat in the pile. A good pile reaches a temperature high enough that you should not be able to hold your hand in the pile, (160 F). If you are not feeling the heat you need to add more nitrogen. Turning frequently will keep the process aerobic, (oxygen using bacteria). Without oxygen the process turns anerobic and a strong ammonia-like smell will result.

Your pile will reduce substantially in size as the bacteria consume the carbon and release it as carbon dioxide. A good portion of your pile literally turns to air. Once the heat subsides and the texture is fine and a deep brown color with no appreciable odor, your compost is finished and can be used in your gardens.

Usually a small layer of compost worked into the surface of the garden or added to planting soil is sufficient. As a rule of thumb, do not use more then 25% by volume, as the salts in compost may be detrimental. Likewise mediums for growing seedlings and such should not contain more the 25% compost, or the salts may injure the delicate tissues.

As in the rest of life, everything in moderation.