Composting is an easily overlooked but highly beneficial method of turning organic waste into a useable resource. Farmers, gardeners, and growers can attest to its properties for supporting the growth and quality of fruits, vegetables, and ornamental plants.
In addition to improving soil health and supplementing the introduction of nutrients, backyard and industrial composting can conserve water, reduce soil erosion, and also cut the amount of greenhouse gasses that enter the atmosphere.
Kitchen composting bins and hot composting heaps have been a standard for backyard gardeners and eco-conscious homeowners, but the low cost of this solution and the need for better waste management and emissions reductions have spurred cities, counties, towns, universities, and private businesses to launch their own organic compost and food waste collection programs.
Now, more than 200 cities in the U.S. have set up curbside food scrap and organic waste collection networks. Diverting all of this biomass away from landfills and into a system that promotes better resource management is no small step towards improved sustainability.
Why Is Composting Important?
Aerobic composting performs an important function. When organic waste like food scraps, dead leaves, and grass clippings are permitted to naturally decompose, they’re broken down by small invertebrates, like worms, beetles, and sowbugs, as well as microorganisms like bacteria and fungi.
This converts waste into nutrient-rich matter that fosters healthy plant growth.
If food scraps or other types of waste are instead mixed in with trash, it ends up in landfills. Although it biodegrades, it does so through a process called anaerobic decomposition.
Anaerobic decomposition releases a byproduct known as biogas, which is comprised of methane and carbon dioxide. Both of these are greenhouse gasses that end up trapping heat in the atmosphere.
Considering that food waste accounts for nearly 20 percent of landfill contents, it’s no small contributor to landfill emissions and overall atmospheric pollution.
Preventing the production of biogas by keeping organic waste out of landfills can reduce the third-largest contribution of human-generated methane emissions, as well as considerable amounts of CO2.
Beyond emission reductions, composting is important for its ability to improve the water retention capacity of the soil. This prevents soil erosion and reduces irrigation requirements. The impact is substantial, as increasing organic matter by just one percent per acre can improve water retention capacity by 20,000 gallons.
In drought-prone areas that are also integral to food production, greater compost integration could further water conservation efforts. It can also help farmers and growers supplement chemical fertilizers by naturally adding more nitrogen, phosphorous, and potassium, as well as trace amounts of calcium, iron, magnesium, and zinc.
Food scrap pickup and curbside composting are convenient and will help ramp up contributions to sustainable agriculture and emission reduction. But if such programs are not available, backyard composting and home-based composting bins still provide benefits. There are two different types of compositing that just about anyone can set up and maintain.
Apartment dwellers, homeowners with limited space, and individuals who simply don’t want to devote a lot of time to their composting efforts can use cold composting. Cold composting is a slow method that allows food scraps and organic waste to passively decompose. This can be done in a covered container or outdoor pile.
Through the cold composting method, scraps are broken down into useable compost over one to two years. Hot composting amounts to a much faster process, with scraps breaking down in as little as a few weeks.
However, this method requires the right balance of moisture, oxygen, and a carefully maintained ratio of nitrogen and carbon. It’s also necessary to periodically turn compost to promote aeration and aerobic decomposition.
This needs to be done more often in the summer—about once a week—and monthly during the winter, depending on local temperatures and climate.