In our last blog post, we covered some of the basic factors that play a role in the process of composting and biological breakdown of organic material. But now that we know the various factors that go into the equation, what's the best approach to actually turn those food scraps into beautiful, black gold? Well, as it so happens, there are a variety of different composting methods that can get us to that end product. Let's explore and define some of the more common composting methods:
Home and Garden Composting
Most commonly seen in the form of backyard composting or creating a small pile at a community garden, home and garden composting is a good method for breaking down yard trimmings and small amounts of food scraps. However, meat, dairy, bones and large quantities of food scraps are not appropriate for home and garden composting (as they won't breakdown properly, and most likely become the snack of backyard animals!).
Vermicomposting relies on a species of worms, red wigglers, contained in bins to feed on food scraps, yard trimmings, and other organic matter to create compost. The worms break down this material into high quality compost called castings. One pound of mature worms (approximately 800-1,000 worms) can eat up to half a pound of organic material per day! The worm bins can be sized to match the volume of food scraps that will be turned into castings, and it typically takes three to four months to produce usable castings. The other byproduct of vermicomposting known as “worm tea” is used as a high-quality liquid fertilizer for houseplants or gardens.
Aerated (Turned) Windrow Composting
Aerated, or turned, windrow composting is best for large volumes of food waste generated by entire communities or high volume food-processing businesses (e.g., restaurants, cafeterias, coffee shops). This type of composting involves forming organic waste into rows of long piles called “windrows” and aerating them periodically by either manually or mechanically turning the piles. The ideal pile height is between four and eight feet with a width of 14 to 16 feet. This size pile is large enough to generate enough heat and maintain temperatures, but small enough to allow oxygen flow to the windrow's core. Because of the temperature the piles can achieve (up to 160 degrees!), windrow composting can break down meat, fish, dairy, and bones as well as compostable products (cups, plates, utensils, etc. made from plants or plant-based plastics). The windrow method is what's used at CompostNow's various commercial composting partner facilities.
This method involves feeding organic materials into a drum, silo, concrete-lined trench, or similar equipment which allows good control of the environmental conditions such as temperature, moisture, and airflow. The material is then mechanically turned or mixed to make sure it's properly aerated. The size of the vessel can vary in size and capacity. While in-vessel composting can process the same variety of material as windrow composting (while using less space to breakdown the material), the equipment can be expensive and require technical expertise to operate. This method can produce compost in just a few weeks, however it takes a few more weeks or months until it is ready to use because the microbial activity needs to balance and the pile needs to cool. Just like a fine wine, compost gets better as it matures.
And those are just SOME of the ways that our favorite soil amendment can be made!