Compost - Black gold for your garden

In nature everything is recycled. Nutrients that fuel the growth of plants and animals are used, transformed, and then discarded. Expired plants and animals and their excreta are all used as resources by other organisms. The waste of one is the food of another.

Between 20 and 45 percent of the average household's waste that ends up in landfill is able to be composted. When plant-based kitchen and garden waste is put in a landfill it costs money and will it produces methane (a global worming gas), it also may pollute groundwater.

A great way of reusing your waste is to compost kitchen scraps and garden rubbish. Your garden will love it. Tiny organism, insects, and worms will turn your waste into nutrient rich compost. The most common composting technique is the traditional aerobic backyard composting. These techniques are not appropriate for apartments and unit dwellers and are often inconvenient, particularly during bad weather in winter in colder climates. Vermicomposting, or composting with earthworms, is an excellent technique for recycling food waste in the unit or apartment as well composting garden wastes in the backyard.

History of compost making and use

Composts have been used for centuries to maintain soil fertility and crop health. It is difficult to say who was the first to make and use compost. The first mention of returning manures to the soil is from the oldest writings on clay tablets of the Akkadian Empire which flourished along the Euphrates River in Mesopotamia in approximately 2300BC.

Cleopatra is said to have seen the value in worms as composters and declared the msacred in 50BC. Marcus Cato, a Roman statesmen, is recorded to have used compost over 2000 years ago. His system was the first recorded use of vermicomposting.

The Greeks and early Hebrews had words for compost and Luke 13:8 has an account of manuring fig trees.

The Middle Ages have many accounts of composting and using compost in agriculture. Modern composting was first described by Sir Albert Howard, working in India from 1905-1934. He experimented with layers of materials and devised what is now called the Indore method after the town of the same name. During the early days of organic gardening, this method was about the only systematic way for the home gardener to convert waste materials into humus. With this method, a compost heap is built in layers, using first a layer of green matter like weeds or leaves. Next comes a smaller layer of manure, which is in turn covered by a sprinkling of topsoil. The layers are repeated until the pile reaches a height of approximately 1.5 metres. The heap is watered and turned after 6 weeks and again after 12 weeks to allow air to penetrate so that the heap will heat up properly. The compost is finished after 3 months and is ready to apply to the garden.

The art of compost making has progressed greatly. Some gardeners are composting the way they did 20 years ago with great success, others use new techniques and methods that speed up the process and bring better results. Making compost can now be done in tumblers, bins, containers or with a worm bin.

Benefits of composting

There are benefits all round if you compost your kitchen and garden waste. There are many environmental benefits if we prevent green waste going to landfills eg transport to get it there, less methane production, less land required. We benefit from healthier and happier plants in our garden and the organisms and micro-organisms that turn our waste into usable compost benefit.

When we add compost to our garden it:

Types of composting containers

Compost can be made many different ways. We can make our own composting containers or we can buy commercial ones such as bins, tumblers, containers and vermicomposters. Some bins are made of woven wire – these are popular because they are inexpensive, easy to build, move and store. Alternative materials include cement blocks, wooden planks, bricks, or stones.

Tumblers make turning compost easier, and a multi-bin composter allows you to start a new compost while the first batch is still being made.

Worm composters can also be home made or commercially purchased. Vermicompost contains not only worm castings, but also bedding materials and organic wastes at various stages of decomposition. Vermicompost also contains worms at different stages of development.

Worm castings contain more than 5-11 times more nitrogen, phosphorous, and potassium as the surrounding soil. Nutrients are made more concentrated and available for plant uptake by the secretions in the intestinal tracts of the earthworms and the soil passing through the worms.

Composting ingredients

Combining the different ingredient in roughly the right proportions is necessary to give micro-organisms such as bacteria and fungi an environment in which to thrive is important. The ingredients are green matter, brown organic material water, and oxygen.

The green matter is high in nitrogen and provides the building blocks for the protein that micro-organisms need to reproduce. Examples are grass clippings, garden plants, and vegetable waste.

Brown organic matter is high in carbon and provides the carbon source of micro-organisms. Leaves, straw, woody plants and sawdust and wood chips are suitable brown organic matter.

The material in the compost bin needs to have enough water to be like a damp sponge. If it becomes too wet air will not get to the organisms – it will become anaerobic.

Oxygen is need for the micro-organisms to breathe. Turning the compost provides the necessary oxygen.

Micro-organisms

The micro-organisms are the natural recyclers. Many kinds of simple, microscopic organisms feed on dead plant materials taking what they need and leaving the remainder. The decaying material undergoes a step-by-step process that results in rich, dark humus.

The compost makers are bacteria, fungi, earthworms, and arthropods. Bacteria are simple microscopic organisms that commence the decomposition process. They are the most numerous organism in the compost material. Bacteria multiply quickly into huge populations that can generate high temperatures. Compost works best in the range of 110-140 degrees Fahrenheit.

Moulds, mushrooms and other fungi are simple plant-like organisms that are made up of a network of root-like structures called mycelium that dissolve and collect nutrients. The mycelium grows and develops spreading throughout the compost. Actinomycetes are small organisms that have properties of both fungi and bacteria, and perform a role similar to that of the bacteria in a compost pile.

Earthworms become more active when the compost becomes more soil-like. Their role is to enrich the humus, by passing the almost finished compost through their bodies, leaving behind their castings.

Anthropods are larger and more complex than the bacteria or moulds.

Compost uses

Compost can be used to enrich vegetable and flower gardens or as mulch around trees, shrubs, or plants, as a substitute for peat moss, and as a compost tea to use as a nutrient-rich liquid fertiliser.