Municipal composting operators must understand the intricacies of making compost to produce a high-quality product. Whether your operation has been going for years or you are just starting one for your municipality, the following are five points you will need to know.
Composting can be compared to microbe farmingMicrobes are responsible for breaking down the materials that create high-quality composting, specifically aerobic microbes. These rely on air for their oxygen supply rather than water, like anaerobic microbes. In order for aerobic microbes to flourish, they do still require water and they must also have a good source of food. In a sense, compost operations are farming microbes to create the compost they sell.
Feedstock material and nutrient balance are importantHigh-quality compost depends on healthy microbes. The green and brown materials you use will affect the nutrient balance you provide to the microbes. You will need to use the right mixture to provide a healthy environment, which will take research and practice. Green materials like grass clippings and manure provide nitrogen, while brown materials like dry leaves and wood chips provide carbon. The size of the materials you use, or particles, will also affect how the microbes grow. Shredding, grinding, and chipping can create particle sizes that give microbes more surface area to thrive. Smaller particles can help create a more uniform pile that insulates well. On the other hand, if the particles are TOO small, they can suffocate the microbes.
There is a connection between moisture content and oxygen flowAs stated above, microbes need moisture and oxygen to survive. Water allows the microbes to get to the nutrients in the composting materials. Feedstock often provides moisture on its own, but sometimes outside moisture is needed in the form of rain or watering. Oxygen must also be provided in the correct amounts and this can be done by aerating the piles. There are many methods for doing this, but turning of some sort should be done. Be careful not to add too much oxygen or you could dry out the compost.
Temperature mattersHaving compost piles that hold optimal temperatures allow microbes to do their jobs, as well as destroy weed seeds and pathogens. The microbes actually raise the temperature of a pile to at least 140° F. If the right temperatures are not met, anaerobic conditions occur, like rotting.
You will need equipment that is up to the taskLarge-scale composting operations require special equipment and tools to produce high-quality compost. Although the supplies you use will depend on your unique needs, there are some that are common to most operations.
- Composting screen: This tool is important for sifting large particles out of your compost. You should conduct some research to see which product is the right for you, as there are many available.
- Starters and accelerators: These start your piles off with microorganisms to do the composting and allow for a faster decomposing environment.
- Compost turner: For large-scale operations like municipal composters, this type of equipment is usually large. The turners introduce oxygen into the mixture and help to make it more uniform. The best way to do municipal composting is to place the piles in long rows known as windrows. Compost turners are often made specifically for windrows and other large piles. When choosing a compost windrow turner, be sure to pick the right one for your operation. You will need to consider the size, the engine, and the powering option (self-propelled, pull-type, and front type), among other options. You can also ask about customization, how easy it is to make repairs and replacements, and the efficiency of each turner.