One of the single best things you can do to improve your garden soil is to add organic matter. By adding significant amounts of organic matter, you are putting fuel back into the nutrient cycle which naturally adds plant nutrients to our soil and lessens (or eliminates) the need for fertilizer. Soil structure is improved by boosting organic matter content, making soils better able to retain water and nutrients.
You may be wondering where you can get some of this wonder material to christen your soil. Why not use materials already present around your home to produce it yourself? This process is better known as composting and it has been a major component of my gardening practices for years. It’s certainly not rocket science, but there are some guidelines to follow which can speed up the process and boost your success.
No matter what you do, composting will happen without much effort from us humans. It is constantly occurring in natural soil environments around the globe. This process of decomposing once living materials into compost, or “black gold” as many call it, is driven by tiny living organisms we cannot see. Microorganisms such as bacteria, fungi and actinomycetes are the driving force behind decomposition. They are aided by much larger critters, such as mites, centipedes, sow bugs, snails, millipedes, spiders, slugs, beetles, ants, flies, nematodes, flatworms, and earthworms. This larger soil fauna starts the decomposition process by tearing, chewing and grinding organic matter into smaller pieces, while the smaller organism finish the job. An efficient composting process takes advantage of what all these little guys do by providing optimal conditions for their life processes.
Like the rest of the biological world, composting organisms need food (nitrogen and carbon from organic matter), water and air to effectively decompose organic matter. Although there are tons of commercially available composting receptacles, compost bins can be made from a variety of materials, as long as they provide the basic needs of the biological life within your compost pile. Conveniently, this biology is already present in the environment and really doesn’t require anything other than food, water and air to do its thing. However, we humans can greatly increase the decomposition rate by catering to the needs of composting critters.
Changes in oxygen, moisture and temperature can inhibit bacteria, the primary drivers of decomposition, or even kill them. When oxygen levels in a compost heap fall below about 5%, aerobic bacteria become inactive or die. These aerobic or “air-loving” bacteria are largely responsible for decomposition and exist naturally in soil by the millions per tablespoon. When their numbers dwindle, such as when oxygen levels dip, the composting process can be slowed by up to 90%. Anaerobic bacteria, which become active when oxygen is limited, can slow or temporarily stop the process altogether. In addition, anaerobic decomposition has a foul odor which can be a sign that your compost needs some air. Therefore, one good practice of a well-functioning compost process is turning the pile periodically to add oxygen.
Just as we humans need a balanced diet to be healthy, soil fauna need the same. Since nitrogen and carbon are their primary food source, it is important to pay attention to the carbon to nitrogen ratio of materials you add to your compost. Generally speaking, nitrogen laden materials tend to be wet and green, such as grass clippings and other plant materials or vegetable scraps from the kitchen. In contrast, carbon rich materials tend to be drier and more brown than green, such as dead leaves, straw, and shredded twigs and stems. An ideal carbon to nitrogen ratio is between 25:1 and 30:1. So you should be adding a much larger quantity of brown, dry things than green, wet things. I have always added new materials in layers of “green and brown” to estimate this ratio.
When you consider the enormous amount of materials we deposit in landfills each year, composting food waste can take a major dent out of our ecological footprint. The US EPA estimates that around 20% of the materials we send to the landfill each year is food waste, which is a staggering number.
If you are looking for something garden-related to do in this season of winter dormancy, consider planning out a new composting facility for your garden area. You may be impressed with the valuable “black gold” you can create by recycling materials that would otherwise be discarded.
Interested in learning more about home composting? The University of Illinois Extension has a wonderfully informative website available at: https//go.illinois.edu/HomeCompost.