Composting is a process that offers a variety of approaches, each having their own merits. Often, small-scale farmers and home gardeners will employ more than one method for composting waste from the kitchen, yard, and garden to minimize waste and recapture those valuable nutrients so they can be reapplied for the benefit of the next year’s crop.
Thermophilic composting or “Hot” Composting
Thermophilic or “hot” composting uses heat-loving bacteria to break down organic material like grass clippings, wood chips, sawdust and leaves. This system of composting waste to recapture nutrients is often used by small-scale commercial farmers and municipalities. The image above shows some of the students from our local Boys & Girls Club on a visit to the Buffalo, WY city dump where neighborhood waste, like grass clippings, leaves, and branches are collected to create valuable compost that is then sold for dirt cheap (see what I did there!)to local gardeners.
Vermicomposting uses worms, red wigglers to be specific, to break down food and garden waste in order to recapture what would otherwise be lost nutrients. The worm castings are often referred to as “black gold” because of the nutrient value they contain. The worms work around the clock along with their bacterial friends to ingest and transform the food scraps. The end result is a bin full of castings that are loaded with nutrients, bacteria, and fungi that are valuable as a natural fertilizer, soil conditioner, and amendment.
Aerated static pile
Aerated static pile composting, like thermophilic composting, uses bacteria to break down organic matter. The key difference is the use of an aeration source to foster the development of the bacteria to expedite the process. Often, aerated piles are exposed to airflow using perforated piping under the pile or fans that direct air to the base of the pile. This composting technique is often used in large scale operations where wets materials are being used in the process.
Aerated Windrow Composting
Aerated windrow composting is perfectly suited to large scale operations and is a preferred technique for municipalities. The City of Buffalo where our flagship Edible Learning Lab is located used windrow composting to process more than 15 tons of compost each year. Materials are piled in long rows up to 8 feet high and 14-16 feet wide. The windrows are tested regularly by the team which monitors temperature and moisture to optimize the timing for turning piles. An attachment on a tractor is used to quickly and efficiently turn the piles thus aerating it for optimal bacterial development.
Sheet composting is often called “lasagna composting” and is just what the name suggests. Inputs are layered in a lasagna pattern and breakdown over time. Brown and green inputs are used in an alternating pattern to create the pile which can be several feet high. The pile is then left to do its thing. Many home gardeners use this method to clear out garden debris in the fall to make the piles which they then cover in plastic. In the spring the beds are ready to go.
Hugelkultur. The name itself is fun to say! Raised beds are created in place using woody debris and plant biomass to created sloped mounds. A retention cover is often used to help keep the mound in place. The material breaks down slowly improving the fertility of the soil, retaining water for plant development, and providing a warmer soil as a result of the decomposition process that is unfolding in the mound. The approach mimics the process that unfolds in nature. Think of the layer of leaves and branches that cover the forest floor. Mounds create rich environments for plants for years with little to no maintenance required once they are built.
Trench composting is the “set it and forget it” of all methods. It’s perfect for the home gardener and a viable method for minimizing the amount of trash you send to the landfill each week. The process is all but invisible, enhances soil value quickly, and requires no maintenance once the trench is filled with food scraps, yard clippings, and leaves and then covered. Home gardeners can trench between rows or even rotate from one row to another where composting can be performed on a rotation of fallow rows.
For more detailed information about individual composting methods you can download our free Definitive Guide to Composting.