COMPOSTING

Compost

The Breakdown

Compost is decomposed organic matter created by the break-down of materials like leaves and food waste by various microorganisms. It contains macro nutrients and micronutrients such as copper, manganese, iron, and zinc that are often absent in commercial fertilizers.  The specific nutrients it has are dependent of the materials used to create the compost. These micronutrients enhance a plants ability to extract nutrients from other foods. Unlike synthetic fertilizers, compost releases nutrients over a long period of time, meaning a long-term supply of nutrients.

Compost is especially good for sandy soil because it helps bind clusters of soil particles called aggregates. This provides good soil structure and helps the soil retain both water and nutrients. In clay or silt soil compost helps to loosen the tightly bound particles so plants roots can spread, water can drain, and air can penetrate. 

The Recipe

The key to a good compost recipe is the balance of carbon, nitrogen, water, and air.

A common and simple ratio to get an acceptable balance of nitrogen to carbon is three parts brown, one part green. Brown refers to materials such as straw, woodchips, and other dry matter and green refers to fresh, damp materials such as grass, kitchen scraps, and manure.To maintain the proper level of moisture, the compost should have a damp sponge consistency. This will give the microorganisms enough water to stay hydrated, but will not be enough to drown them.When a compost pile is first created it likely has a sufficient amount of oxygen, but the microorganisms consume it as they work making it necessary to replenish the oxygen levels. This can be done by simply turning the compost.

Sacramento's State's compost program is a seven-step process

  1. Campus food and landscape waste are collected and chopped into small pieces.  Small material composts at a faster rate than large material because of the increased surface area.
  2. The materials are combined into a “pile”.  Microbes immediately begin to eat, digest, excrete, and reproduce.  These microbial processes heat the pile quickly.  Once the pile reaches a temperature of 130 – 140 degrees F for 5 days, the pile will be free of weed seeds and of pathogens as well. 
  3. As a precaution, the pile is turned after these first 5 days, and allowed to reach 130 – 140 degrees one more time.
  4. At this point, the pile will be ready for the worms because it will not overheat them.  The pile is ready for human use, because any potential pathogens have been eliminated through the compost’s initial heat process.
  5. The material is now turned over to the worms, which eat and live in this material.  They will process the same material several times.
  6. Each pass through a worm’s tract enhances the microbial content.  In essence, they refine this soil amendment.  As they eat, they reproduce.  Managed and harvested properly, our worm supply is inexhaustible.
  7. After several passes, the material and the worms are separated.  The worms can be added to new material as composters, or used as a high quality protein source for fish.