What about our food scraps and organic household waste? The next section of this unit deals with just that. In introducing composting as a method of recycling I will explain how compost is nature’s way of recycling. Composting is a natural way of replenishing needed nutrients to soil, improving it and creating an environment which plants thrive in. It is also one of our easiest ways to reduce our household garbage volume.
Composting turns organic materials into a rich mixture that improves soil and supplies nutrients to plants. Besides building good soil and controlling erosion, composting helps conserve resources and reduces the need to use chemical fertilizers. In the book,
All I Really Need to Know I Learned in Kindergarten
, Robert Fulghum states very simply, “If you make a mess, clean it up.”
Learning to compost is the first step we can take in cleaning up our mess and reducing our household waste. It is an appealing method of recycling because it is easy to learn. Types of compost, benefits of composting, how to’s, materials and uses of compost are covered in this section. Student activities are designed to simulate this concept.
Composting is one of the easiest ways to reduce vegetative waste and turn it into a usable product. It is the biological reduction of organic wastes to humus.
In early days when hunting for food was common, man began to compost. Sir Albert Howard, a British government agronomist, studied an organic method of gardening and farming in India from 1905-1934. He devised the Indore method of compost making, in which materials are layered sandwich fashion, then are turned (or are mixed by earthworms) during decomposition. Worms, insects, fungi and bacteria are important decomposers.
Today farmers realize that these organic methods restore life to the soil and reduce their use of chemical fertilizers. Plants, animals, insects and people are all linked together in a web of interrelationships with natural resources. Nature is a continuous composting program. Leaves which fall from the trees are composted and become available nutrients to the trees. Birds, animals and insects also contribute their wastes to help grow food. If we look around us at the earth’s greenness we are able to see the vast possibilities of nature’s composting program. In summary, compost builds good soil texture and structure, helps control erosion, recycles biological wastes, provides and releases plant nutrients, protects against drought, controls pH, supports essential bacteria, feeds helpful earthworms, stops nutrient loss through leaching, acts as a buffer against toxins in the soil, controls weeds, stretches the growing season and conserves our nation’s nonrenewable energy resources.
Decomposition is accomplished by the enzymatic digestion of plant and animal material by soil microorganisms. Processes of oxidation, reduction and hydrolysis are going on simultaneously. Their end products are used by the microorganisms for further breakdown.
Bacteria use the products to provide energy for their life processes. This energy is obtained by oxidizing the products. Raw materials have to be of biological origin for decomposition to occur. Then they are broken down to simple forms of proteins and carbohydrates. Carbohydrates break down into simple sugars, organic acids and carbon dioxide. Proteins break down into peptides and amino acids. Through this biological process, the decomposition eventually forms humus. Humus is the finely divided organic matter in soil, derived from microbial decomposition of plant and animal materials. Humus is valued by farmers and gardeners because it provides nutrients essential for plant growth, increases soil water absorption, and improves soil workability.
Because recycling garden and food wastes is a natural process it is important to practice this for maintaining a good environment. Backyard composting is one step we can take towards conserving our energy supplies and regaining control of our food supplies. To begin a compost pile, first you need to choose an area. Once you’ve chosen the proper area, you can spread the bottom with twigs, corn stalks or wood ships. Next you need a layer of finer materials such as grass clippings or small pieces of kitchen waste. Then a layer of dirt is placed over the garbage and moistened. This “layering” is repeated into the compost pile until the pile is about five feet high. A plastic sheet with small holes in it is sometimes placed on top. The compost pile has to be able to support the activity of the compost organisms. Moisture, temperature, pH and oxygen availability all influence the process. Composting can be done with or without oxygen. Decomposition in nature is mostly aerobic, i.e. done with oxygen. If the compost heap begins to smell there is not enough oxygen. Aerobic composting promotes high temperatures. The decomposition process is slower when the temperature is high, however high temperature is important to destroy weed seeds, insect eggs and harmful organisms. The compost pile also needs to be moist so organisms can thrive. If it is too moist, anaerobic conditions can develop and an unpleasant odor can occur. The pH should be between 6 and 7.5 and can be tested with litmus paper. Acid conditions can be controlled by adding some absorbent materials to the heap.
Once a compost pile has been activated, it is easy to provide a balance of nutrients for it. Kitchen wastes are one of the best sources of nutrients. Some of them to consider are banana skins, citrus rinds, coffee grounds, corn cobs, eggshells, nutshells and tea leaves. These materials decompose more rapidly when chopped or shredded. Other sources of nutrients include: hair and feathers, cut into short pieces (they are high in nitrogen content); leaves which are made up of fibrous organic matter gives good soil building quality; grass clippings, weeds, manure, straw, sawdust, wood ash, limestone, phosphate, rock, cottonseed meal and seaweed are all great nutrients.