Compost Season is Upon Us (Part 1 of 3 Part Article)

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1 Compost Season is Upon Us (Part 1 of 3 Part Article) As my compost pile begins to thaw out I have visions of harvesting my first batch of the season. This activity, more than any other, gets me into the gardening mode. I love the texture of finished compost, and that rich earthy smell. My imagination can easily see the tender plants and seedlings bursting forth as compost is added to the soil. Any type of plant can benefit from compost. Composting is not a new technology. Prior to the widescale use of chemical fertilizers, U.S. farmers typically spread composts made from animal manures, plant materials, and other organic products to enrich the fertility of the soil. The renewed interest in organic farming and gardening techniques, such as composting, can be attributed to increased awareness of the potentially adverse environmental and human health effects associated with chemical fertilizers and pesticides. Compost is not considered to be a fertilizer, but rather a soil amendment, although it does contain low levels of essential plant nutrients. By composting yard materials and food scraps, homeowners can reduce the amount of waste requiring disposal. In addition, a useful soil amendment is produced that, once applied to lawns and gardens, can condition the soil and replenish nutrients. Home composting saves transportation and disposal costs and has a direct impact on the amount of waste requiring disposal. What exactly does compost do? Compost enhances the structure of soil by binding soil particles together. This improves aeration and the ability of the soil to retain water and nutrients. Compost improves drainage in clay soils and water retention in sandy soils. Compost improves the buffering capacity of the soil and minimizes adverse effects to plants due to extreme shifts in soil ph. Want to attract earthworms? Adding compost to soil attracts earthworms, which aerate the soil and add additional nutrients to the soil. If all that wasn t enough, compost can store nutrients and release them slowly for use by surrounding plants. Compost is nature s way of recycling. It s also amazingly satisfying. The Keene Recycling Center on Route 12 North sells compost bins at wholesale prices. Start a lifetime hobby today. The next article will be about the biology of composting and how you can compost successfully. The Biology of Composting (Part 2 of a 3 Part Article) Composting is a controlled biological decay process that involves many species of microorganisms and invertebrate animals. In nature, dead animals and plants decay slowly. Composting involves human intervention to manipulate various organic materials and environmental conditions to speed up this process. A properly constructed compost pile represents a remarkably interactive biological and ecological system. It involves a

2 diversity of species that emerge in response to changes in the nutritional and environmental conditions of the pile. Following a few simple guidelines will prevent unwanted visitors to the compost pile including rodents, raccoons, and flies. The decomposition of organic material involves both physical and chemical processes. The decomposition of organic materials into smaller compounds results from the activities and appetites of various invertebrates such as mites, millipedes, beetles, sowbugs, earwigs, earthworms, slugs, and snails. The chemical decomposition of organic compounds results predominately from soil microorganisms. These include bacteria, actinomycetes, fungi, and some protozoans. Under the appropriate conditions, complex organic compounds present in food scraps and yard trimmings are enzymatically degraded into smaller compounds, carbon dioxide, and water. Heat is also generated as a by-product of this oxidative process. Composting continues as long as appropriate microorganisms are present and adequate environmental conditions are maintained. Once the decay process is completed, the nondegradable organic matter becomes the characteristic humus-like material called compost. Providing adequate sources of carbon and nitrogen is important since these elements are required by microorganisms for growth and cell division. Carbon also serves as an energy source for soil organisms. Ideally, the ratio of these nutrients in the compost system should approximate 30 parts carbon to 1 part nitrogen (by dry weight). This allows for the most rapid and efficient degradation of the organic material. Food scraps and yard trimmings can be classified into two categories according to their carbon and nitrogen content: "Green" materials, such as fresh grass clippings, manure, garden plants, and kitchen scraps contain large amounts of nitrogen. "Brown" materials, such as dried leaves and plants, branches, and woody materials have a high carbon content but are relatively low in nitrogen. Through experimentation and patience, a suitable formulation of green and brown materials will be derived. This is part of the art and science of backyard composting. For example, mixing together equal volumes of fresh grass clippings ("greens") and dry leaves ("browns") is a simple "recipe" for novice backyard composters. Materials to Include in Backyard Compost Aquatic plants Bread Coffee grounds Egg shells Farm animal manure Bones Materials to Exclude in Backyard Compost Pet manure (e.g., dog, cat) Dairy Products Diseased plants Fish scraps

3 (e.g, sheep, cow,horse, poultry) Fruit Garden trimmings Grass clippings Hair clippings Leaves Sawdust Lard Mayonnaise Meat scraps Peanut butter Salad/cooking oils Salad dressing Straw Sod Tea leaves Twigs and shredded branches Vegetables Wood ash (small amounts) Aeration refers to the amount of oxygen in the system. The types of organisms active in the pile and the metabolic processes used to degrade organic compounds are related to the oxygen content of the system. Air can be introduced into the pile by turning the materials periodically with a pitchfork. Most problems associated with composting (foul smelling compost piles) can be corrected by turning the compost pile. Maintaining an adequate moisture content is essential since it provides the humidity required by microorganisms for optimal degradation. Water also dissolves the organic and inorganic nutrients in the pile making them available for utilization by soil organisms. A moisture content between 40 to 60 percent by weight throughout the pile is ideal. Exceeding this level slows decomposition and promotes anaerobic degradation. Moisture levels less than 40 percent cause the microbes to slow their metabolic activities and become dormant or die. Moisture is a key ingredient to the compost process. The optimal moisture level is achieved when the composting material feels damp to the touch; that is, when a few drops of liquid are released after squeezing a handful of the material (e.g., as wet as a "wrung out" sponge).

4 To increase the rate of decomposition, yard trimmings and food scraps should be shredded, chipped, or otherwise reduced in size. This is especially important for woody materials, large garden plants, and some fruit and vegetable scraps (e.g., citrus rinds, broccoli). Fallen leaves can be shredded by mowing them prior to raking and composting. In a loose pile, a homemade bin, or a commercially sold compost bin, you can make compost. It s easy, fun and provides a valuable soil amendment for your flowers, vegetables or lawn. Backyard Composting Methods (Part 3 of a 3 Part Article) Backyard composting is attractive to many homeowners since it can be adapted to fit their lifestyle, income, yard size, and overall ambition. Home composting can be performed by a variety of methods. Typically, these include: - placing materials in open piles - enclosing materials in drums or bins Ideally, compost piles should be at least one cubic yard in size (a pile 3 ft. by 3 ft. by 3 ft.). This provides the minimal insulation required to sustain the high temperatures in the center of the pile. Basic composting units or bins can be constructed at home from inexpensive materials or can be purchased at garden centers, through garden supply catalogs or at the Keene Recycling Center. The slow or "cold composting" method is the simplest way to compost yard trimmings and requires minimal work. A cold compost pile can be maintained as an open pile or enclosed in a holding bin. Materials in a cold compost pile degrade slowly since no effort is made to mix and aerate the materials. New material is merely added to the top of the pile. Finished compost (i.e., the material at the bottom of the bin or pile) is generally produced within one to two years. When you add fruit and vegetable trimmings, these should be lightly mixed into the pile to discourage animals and insects. The fast or "hot composting" method requires more work on the part of the homeowner. Finished compost can be produced within several months (unless you really know what you re doing, don t believe the hype that you can produce finished compost in a couple weeks). This method requires that materials be composted in the correct carbon and nitrogen proportions. Food scraps should be buried in the central and hottest portion of the pile. A properly constructed hot compost pile will heat up rapidly (i.e., over 100 deg. F within the first week) due to microbial activity in the pile. Maintaining this rapid degradation rate requires frequent mixing to aerate the pile and control its moisture

5 content. Unless it is properly constructed and maintained, a hot pile can "short-circuit" and revert to a much slower cold composting system. You like the idea of composting, but don t want a compost pile in your backyard. Have we got a deal for you. The Keene Recycling Center has a giant compost pile primarily consisting of leaves collected in the fall along with a small amount of grass clippings and other organics. The City of Keene is currently participating in the Cities for Climate Protection Initiative and is actively working to develop a plan to reduce greenhouse gas emissions. Pursuant to the City of Keene s participation in the Cities for Climate Protection Initiative, the City of Keene Solid Waste Division is expanding its compost operations to include food waste composting. The City of Keene recently secured a permit from the New Hampshire Department of Environmental Services to begin small scale food waste composting. A customer survey conducted during the summer of 2001 revealed that approximately 33% of the respondents were interested in bringing food wastes to the City of Keene Solid Waste Facility for composting. With over 15,000 residential drop-off customers at the Solid Waste Facility per year the potential to divert food waste is significant. Types of food waste accepted would include items such as fruit and vegetable scraps, bread products, egg shells and coffee grinds. These items would be incorporated into the existing leaf and yard trimmings compost material as a rich nitrogen source. The City of Keene s interest in expanding compost operations stems from the idea that compost represents a potential carbon sink whereby compost has the ability to store carbon dioxide rather than releasing it to the atmosphere. The City of Keene s compost initiative would be a part of the City s overall strategy to reduce greenhouse gas emissions. Whether in your backyard or our backyard now you have a many good reasons to compost. Start today when you are making your dinner salad, or your breakfast omelet. It s easy, fun and it really does make a difference. Composting Bins are available, just ask.