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Home Composting

Why? Compost is a rich-dark, crumbly and earthy-smelling form of decomposing organic matter. It is a valuable soil amendment for use within the garden and landscape plantings. Its presence improves the soil tilth by binding soil particles together, increases the soil’s moisture-holding capacity and releases nutrients such as nitrogen for plant use. Composting is the most practicable and convenient way to handle your yard waste and some food waste, too. It is easier and less expensive than bagging yard waste or taking it to a transfer station or landfill. If you have a lawn, trees, shrubs or even planter boxes, you have a use for compost. Compost returns organic matter to the soil in a useable form. Improving soil is the first step in growing healthier plants. Healthy plants clean our environment, air, water and conserve soil. The result is a healthier place in which to live. What? Anything that was once alive is compostable: yard waste such as leaves, grass clippings, manure, straw, hay, plant refuse from the garden and kitchen. Mature corn stalks may take more than a year to form compost. Clip or shred woody yard waste and use it as mulch or for path making. Larger branches may be burned in the fireplace or stove. Finely shredded newspaper mixed with other nitrogen supplying material is also compostable.

Diseased plants should not be composted if the compost will be returned to the garden later. It is acceptable as a lawn top dressing. Although natural compost heating kills some diseases, unless it is turned frequently and allowed to remain unused for several years, some diseases may be returned to the garden. Avoid composting weeds laden with seeds. If the composting process is not complete, some of these may be returned to the garden. Put bones, fat and fatty foods, fish, grease and meat scraps in the garbage, not in compost. These attract animals, and may create odors during composting. Do not add pet waste to compost. How? Use compost as enrichment for flower and vegetable gardens, improve the soil around trees and shrubs, as an amendment for houseplants and planter boxes and when screened as a lawn top dressing. Seed starting mixes should not contain compost, minimizing the chance of introducing

disease. Composting is a disintegrating process. The organic matter is broken down by the action of numerous organisms, including bacteria,

fungi, and higher creatures. During this composting process, the energy in the roughage is lost as heat. The volume is greatly reduced. Some nutrients are lost by leaching or escaping gas. See Table 1 for the changes that occur in nutrient content of composts of different ages.

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Table 1.

Age of Compost Nitrates Phosphorus Potassium pH Soluble salts 3 years 20 115 40 7.1 39 2 years 38 18 50 6.9 53 1 year 137 20 250 7.6 130

Contents determined by Spurway test, ppm in extract solution Bacteria and fungi work in creating compost when the composting material is kept moist, has access to oxygen and contains nutrients high in nitrogen. Fertilizer furnishes nutrients the soil organisms require for rapid growth. Leaves, straw or other materials low in nitrogen require the addition of nitrogen to prevent excessive loss of bulk; bulk is, in part, determined by the nitrogen level present. What goes on in the compost pile is a very complicated biological process. Various systems shorten the time for producing compost and increasing its value. These are mostly related to increasing the oxygen and nitrogen supply. Practically, building a compost pile is not an exacting process. Locate a compost-holding unit in an out of the way location that is convenient to where the organic waste originates. Numerous units are suitable for holding the organic matter. Staked circles of small mesh wire fencing or plastic mesh or wooden pallets are inexpensive options. Tumbling barrel units reduce the labor required for turning the compost. These are probably the most expensive units. One may also construct bins of wood or concrete blocks. Turning units are a series of three or more bins that allow turning of wastes on a regular schedule. Large volumes of yard waste, creating high quality compost, flow from such a unit. Build the unit on the ground leaving the sides open because oxygen is essential for decay. (For details on composting container construction, request the fact sheet Building Bins and Boxes for

Compost.) Start a pile by spreading out alternating layers of high nitrogen green plant material and high carbon

brown plant material six to eight inches deep. Plan to have the finished pile no more than two feet to its center. More than this and oxygen will not penetrate to that center. The material available should be sufficient for at least four or five layers. A readily available nitrogen fertilizer source may be added to each brown layer (for example, 10-10-10 @ the rate of 1/2 pound to each 30 square foot of layer surface). Organic nitrogen sources such as: alfalfa hay, cottonseed meal, dried blood or poultry manure may be substituted. If alkaline compost is desired, add ground limestone at the same rate, although this is usually not necessary. Although not necessary, a few shovels of garden soil may be spread over each layer assuring the presence of decay organisms. Moisten each layer thoroughly to the consistency of a damp sponge. Successive and alternating layers are built in the same manner until all plant refuse is used. Build a flat top pile with a shallow dish to the center that captures rainfall. A large pile that gives off steam is overheating and is not well moistened. Add more water to slow the heating process. The temperature should rise above 100°F. within a week. After the temperature drops below that, the pile may be forked over, adding water to dry spots. This restarts the heating process, hastening its decomposition. After a second cooling, close examination should not detect recognizable plant parts. It is advanta-geous to get it on the land before it loses all its structure. If uniformly fine textured material is desired, turn the pile again and continue the rotting process. Do not accumulate compost in the same place year after year.

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Whether pests or diseases persist in the compost depends on the organisms present and the heat generated in the decay process. Practically, compost is spread on gardens without disinfestation. Amateur soil sterilization is not practical. Organic matter may be used as a mulch without composting, although it may be harder to handle and be unsightly. Place lawn clippings and other fine material around shrubs or on garden plots where appearance is not as important. With limited space, composting may be done using worms, garbage cans or commercially available composting vessels. (For information on vermi-composting, request the Guide to Worm Composting fact sheet.) The “Green Cone” vessel is buried twenty inches in the yard. Kitchen waste added to the vessel breaks down to compost.

Copious amounts of compost are not made, but valuable kitchen waste is not lost to landfills. A plastic or metal garbage can with several holes punched in the sides and base provides a reservoir for making compost from kitchen plant waste. Place a catch pan beneath the can to collect any liquid that seeps from the compost in action. This fertilizer tea may be used on houseplants or the garden. A foundation of soil is placed in the bottom. If done indoors, red worms are then added. Layer shredded newspaper or leaves with plant waste from the kitchen. In about three or four months the can may be emptied and screened, removing the finished compost, returning the rest to the can for reworking.

Table 2.

Symptoms Problems Solutions Compost has bad odor Not enough air. Turn it. Center of pile is dry Not enough water Moisten while turning the pile Compost is damp & warm in center, but not elsewhere.

Pile too small. Collect more material. Mix old ingredients with new into a new pile.

Pile is damp & sweet smelling but does not heat.

Lack of nitrogen. Mix nitrogen source like fresh grass clippings or manure, blood meal or chemical fertilizer high in nitrogen

Summary. The compost pile is a teaming microbial farm. The process begins with bacteria, followed by fungi and protozoans and lastly by centipedes, millipedes, beetles and earthworms. Anything growing in your yard or plant material from the kitchen is food for these decomposers. Carbon and nitrogen from dead plants fuel their activity. Carbon is the energy source for microorganisms. Nitrogen provides microbes with the raw elements of proteins for bodybuilding. The more surface area microbes have to work on the faster the material is decomposed. Shredding or chopping plant refuse before it is added to the compost pile speeds the rotting

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process. A large pile insulates itself and retains the heat of microbial activity. Piles less than 3 feet on a side have trouble holding heat. Piles larger than that do not allow enough air to reach the microbes in the center. Composting action requires water. Solar energy and rainfall affect the pile’s moisture. Remember that good compost feels like a damp sponge. The faster the composting action, the higher the temperature of the compost. With the proper carbon to nitrogen ratio (30:1), lots of surface area and sufficient volume combined with adequate moisture and air, you have a hot pile capable of intensive management. This yields compost in six to eight weeks. With no additional labor, once constructed, a layered pile of organic refuse will turn to compost in a year or less. 8/1997 Chemung County

Heavy mesh wire or snow fencing can be used to construct a freestanding cylinder-shaped compost bin. When it’s time for the compost to be turned, the fencing can easily be rolled away from the pile and set up in a nearby location. The freed pile of partially decomposed material can then be placed back into the empty bin.

A double-bin system facilitates the procedure of forking over compost material. After the compost is allowedto partially decompose in one bin, it can be moved to the adjacent empty bin, a lower center wall in the bin making the transfer of compost easier. Bins can be constructed of material such as scrap lumber, snow fence, or cinder block. The exact dimensions of the bin are not critical. For a typical home garden a bin 3-4 feet in height and 5-8 feet square will suffice.