Composting in nature and in your backyard

Contribution made by Ross Lebold, Conservancy Land Protection Specialist

Composting in nature and in your backyard

In a recent survey, many Ohio Chapter volunteers were interested in information on composting. The first part of this article examines how it occurs in nature and in our forested preserves. The second part will discuss how you can do it in your own backyard, something that helps the environment and your pocketbook. As the leaves have begun falling, we felt there wasn't a better time to discuss this important topic!

Composting in nature

A common expression about nature is that ‘nothing is wasted.’ This is hardly a startling revelation even to the casual observer: Fruit and prey are consumed, carrion is reduced to bones, and dead trees are excavated by woodpeckers and beetles. But what about the dead leaves and twigs which fall to the forest floor each autumn?

Although not evident through simple visual observation, the forest floor is an area of great biological activity. In this narrow zone, a variety of invertebrates, bacteria, actinomycetes and fungi are enlisted to decompose any and all organic material which happens to ultimately rest there. This work begins with arthropods and worms which reduce the size of the material and transport it to other locations within the soil horizon. This is followed by the activity of the microbes which strip off sugars, starches, and proteins in relatively quick order. These compounds are repeatedly recycled as the organisms die and release them for reuse. The remainder of the vegetation such as lignins and cellulose are not as easily broken down and persist for much longer. These more resistant materials form the bulk of the material known as humus.

In the forest, the humus layer is an important component of the ecosystem due to its ability to retain water and temporarily store nutrients which can be used by living plants. In temperate climates such as ours, humus can accumulate and contribute greatly to the soil. The level of accumulation is usually a function of temperature, moisture, and available oxygen. The greater the temperature or amount of oxygen, the more rapid the decomposition of organic material becomes and less accumulation is able to occur. This is why the typically sandy tropical soils are often much less fertile than temperate soils.

Humus has colloidal properties (i.e. – it is chemically active) which allows the clumping of soil particles into aggregates. Colloidal properties also allow the soil aggregates to bind to nutrients and mineral salts which are available to living plants (known as cation-exchange capacity). Soil aggregates can also be formed from soil particles held together by organic glues derived from the remains of decay organisms. This formation of aggregates creates a condition often referred to as ‘crumb structure.’ Additionally, humus can increase soil porosity which is important for the transport of water and gases through the soil. Combined, these attributes contribute to a soil’s ‘tilth.’ Although a general word used primarily by the agricultural industry, tilth is a term most commonly used to describe a soil’s ability to be easily worked.

Humus, for all of its contributions to the formation of arable lands, could be considered the ‘capital’ within the soil. Although it is resilient, it can be easily destroyed. Excessive tillage overexposes humus to oxygen and accelerates its decomposition. This results in a depleted soil and leads to a greater dependence on chemical fertilizers and subsequent and nutrient pollution. Depleted soils are also prone to higher levels of erosion and compaction. With proper management and time, these soils can be restored.

Composting in your backyard

The same biological activity that is occurring on the forest floor can easily occur in your backyard. All you need to do is supply the ingredients and a little time, nature will take care of the rest.

Research has found that at least 20% of waste produced by communities is yard waste (this figure can get even higher in rural areas). It is the second largest component of waste we dispose of behind paper and paper products. In the past decade, many communities, municipalities, and townships have mandated residents dispose of their leaves in biodegradable paper bags that they can compost and use on their own land while cutting back on yard waste in their landfills.

If you have yet to compost on your own, here is a quick tutorial on how to do it. Why don't you give it a try this fall and reap the rewards this summer!

Compost bins

While most people prefer to use an enclosure for composting, it is also acceptable to compost in open piles. It usually depends on location, how much room you have, and aesthetic considerations. The location shouldn't be in direct sunlight is that might inhibit the correct amount of moisture in the pile. And you don't want to offend your neighbors with a compost pile that might get a little odorous next to their kitchen window.

If you want to have structure to your compost pile, there are several options that you could use. You can make a compost bin via several materials. One can use chicken wire staked to the ground, cinder blocks piled without mortar with air spaces between them, logs or poles laid in a log cabin fashion, or a steel barrel with the bottom removed and holes punched in the side.

There are also prefabricated bins or barrels that you can purchase on the internet or home centers as well. Depending on size and composting needs, they can range from under a hundred dollars to several hundred dollars.

If you make a bin out of chicken wire, cinder block, or logs/poles, the average size should be five feet in height, width, and lengthen. The bin should not be smaller than 4X4X4 or bigger than 6X6X6, as the temperature inside the pile can become too warm or cold.

Ingredients

A proper compost pile has five ingredients; organic matter (nitrogen-rich greens and carbon-rich browns), bacteria, water, and oxygen.

Most organic yard wastes can be composted. Nitrogen organic matter acts as a source of protein for microbes hard at work in the compost pile. Examples of nitrogen organic matter include green leaves, eggshells, fruit and vegetable scraps, coffee grounds, tea bags, hair, manure, bloodmeal, fresh grass clippings, and nitrogenous fertilizer. Carbon organic matter provides energy for the microbes and included dried leaves, plant stalks, vines, weeds (not gone to seed), twigs, and branches. Shredding leaves via lawn mower or bagged blower/vacuum hastens the compost process. Meat, fish, pet feces, dairy products, and plants infected with or are suseptable to disease are not good candidates for composting (such as roses).

Bacteria is something that you won't have to add as decomposers always live in soil and vegetable matter. Nonbacterial composters, such as fungi, worms, and invertebrates, will work on decomposing your pile as well.

As bacteria need oxygen to live and multiply, compost piles should be well ventilated. If your pile becomes odorous and you are using proper ingredients, your pile may not be getting enough oxygen and anaerobic bacteria may be taking over.

Water helps decay the materials, but if there is too much water, the bacteria won't get enough oxygen. A typical pile should have the dampness of a wrung out sponge. Piles consisting mostly of leaves should be monitored as leaves dry our quickly.

Layering of compost

The bottom of the compost should be the ground. Turnover the soil before starting the pile. The first layer should be 6 to 12 inches and consist of carbon-rich leaves and plants. The next layer should be a few inches thick and consist of nitrogen-rich fresh grass clippings, manure, and/or vegetable trimmings. Alternate layers until you get to your appropriate height level. You should add a thin layer of soil or manure on top of the pile.

If using grass clipping, there is no need to water the pile initially. Fresh grass clippings are 80% water and will provide enough moisture. However, if you are using a lot of dried leaves and little grass clippings, water as you go.

Mixing the pile

Compost made in the fall should be ready for use the following summer. You will need to mix the pile periodically with a pitchfork or shovel once a week for two or three weeks, and then once a month until the compost is ready to use. Mixing the pile brings oxygen into the pile and helps break up the materials into smaller bits. If the pile is dry, add water. If you take a handful, squeeze, and don't see beads of water, the pile is too dry.

Properly made compost heaps reach 130 to 160 degrees at its center, so when you mix the pile steam may rise from its center. Turning the pile maintains the temperature and ensures that all material is exposed to the center heat. The pile will no longer heat up when the compost is finished.

How to use finished product

"Black gold" is what gardeners call the finished product and you can use it many ways. While it isn't fertilizer, it does contain nutrients that improves plant growth. You can mix compost to the soil in your garden beds. In sandy soils, it acts as a sponge, retaining water and nutrients that can be reached by plant roots. In clay soils, it makes the ground more porous, which helps soil drain more quickly. You can also use compost to fill low spots in your lawn, as mulch for landscaping and garden beds (at a depth of two to three inches), and soil for potted plants.

Whether taking a hike through the woods or spreading compost around your backyard, nature reminds all of us that nothing is wasted!

Resources

Composting: A citizen's guide to the proper disposal of leaves and other organic materials. (1997). Columbus, OH: Ohio Environmental Protection Agency. Retrieved August 23, 2005, from http://www.epa.state.oh.us/pic/facts/compost.html

How to compost your organic waste. (2005). St. Paul, MN: Minnesota Office of Environmental Assistance. Retrieved August 24, 2005, from http://www.moea.state.mn.us/campaign/compost/

How to make compost. (2005). Harrisburg, PA: Pennsylvania Department of Environmental Protection. Retrieved August 25, 2005, from http://www.dep.state.pa.us/dep/deputate/airwaste/wm/recycle/FACTS/compost.htm

How to make compost, a composting guide. (2005). Compost Guide. Retrieved August 24, 2005, from http://www.compostguide.com/

Michel, F.C. Jr., Heimlich, J.E., & Hoitink, H.A.J. (2005). Composting at home. Columbus, OH: The Ohio State University Extension. Retrieved August 23, 2005, from http://ohioline.osu.edu/hyg-fact/1000/1189.html