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The breaking down, or rotting, of dead organic material occurs naturally, all the time and everywhere. It is vital to our existence for without it, we would be up to our necks in a sea of garbage.
When the process of handling organic waste is ‘managed’ on an industrial basis, we call it ‘waste management.’ When we do it at home, we call it ‘composting’ and the end result we call – ‘compost.’ The word, ‘compost’ derives from Latin (composita, ‘to put together’) and French (you know – compote – stewed fruit.) In England, the word has been used in its present form since around the 14th Century according to Collins English Dictionary.
The word, according to the Oxford Dictionary, has two meanings.
- “decayed organic material used as a fertiliser on plants”
- “a mixture of compost or similar material with loam soil used as a growing medium”
As you see, they are closely related.
The Role of Composting
It is reasonable to say that anything that was once living can be composted – it will certainly rot. Plants, animals or micro-organisms, none are immune to the cellular degradation that starts to occur once life is snuffed out.
When we collect a load of dead or dying materials and combine them, we are creating a compost heap. These materials will rot down and eventually turn into a soil-like substance that contains all the mineral goodness that was in the original ingredients. It will contain a population of soil-dwelling micro-organisms that will be of huge benefit to the earth and the plants that grow in it and finally, it will help to condition the soil to which it is added.
It is a wonderful thing, and we need to appreciate that without these mechanics of degradation and rejuvenation our life on this planet would not be.
To understand about composting, you first need to appreciate its key role in at least two of the ‘cycles of life’ that are crucial to our survival – the nitrogen cycle and the carbon cycle, each of which is a part of the mechanism that allows life to continue on our planet. Secondly, it helps to get your head around the idea that Everything Living Dies and has to be properly dealt with in some way. Re-cycling is nature’s way of disposing of organic matter that has died – converting its elements back into a form that is usable once again, allowing new life to appear and giving it sustenance.
This process is one of our ways of dealing with the organic waste that we generate, but unfortunately present practice is not nearly robust enough to even nearly solve the vast heaps of rubbish surrounding us. Using anaerobic land-fills is no longer an option. There is not enough room and the resultant chemical pollution is not even to be considered. Animals do their bit according to their habits. (Where would we be without sea-gulls and rats and birds of prey?) But they cannot do it alone.
We humans are chiefly responsible for the staggering amount of organic rubbish, (let alone the inorganic stuff) that requires clean, safe disposal and we should be using our kitchen waste and trimmings from our gardens and lawns to fuel our compost piles. We should also be encouraging community efforts in this field. At least then, we are making the effort to clean up a part of our own mess. Here we have a win-win method of re-cycling and on a domestic level, it can be an almost effortless operation.
On a personal level, how can we exploit the rich gifts that this amazing substance offers? Well, if we are gardeners, of course we have a very good idea of what we can gain from using this stuff, this black gold.
Firstly, if it is made well, it is an excellent fertiliser. If we control what we add to our bin, we can ensure that the end result is chemical and disease free and over-flowing with the nutrients so desperately needed by our soil. If our soil is lacking a specific mineral, we can make sure that the ingredients we use will supply it.
A catch-phrase that, to me, encapsulates the whole idea of garden composting, is, “Compost works on the soil while fertiliser works on the plants.” Think about that for a moment. Here we have the complete opposite of much of what we buy to feed our gardens. Those artificial fertilisers are applied, sucked up by the plants and that is that. When using our product, however, the nutrients are bound up in the structure of the soil in a form that is slow-release and is easily absorbed by adjacent root-systems over a period of time. It also offers protection to the roots from pathogens and a variety of pests.
As a soil amendment, it helps to mitigate clay soils by breaking them up and providing channels that allow the passage of oxygen and moisture. In sandy soils, it provides structure, enhancing water retention and preventing erosion. All of this contributes to the growing environment, giving plants their best opportunity to thrive.
In nature, a good example of natural decomposition is the forest floor where the ground is covered with a thick layer of dead and partially rotted leaves and twigs that have fallen from the trees above. This mix of leaves in various stages of decay is known as ‘humus’ and in this situation, its primary function is as a mulch. Because its original ingredients are limited, it is not the best fertiliser in the world, but it offers fantastic protection to the forest floor and the roots of the trees. It insulates the roots from extreme temperatures. It helps to keep the soil moist in dry weather and it inhibits soil erosion in severe rain. It also provides a habitat for small insects and animals, all of which have a part to play in the life of the forest and helps to stifle the growth of weeds and seedlings around the base of the tree trunks.
Just another role for ‘black gold’ to play in the eco-system.
How Does it Actually Happen?
Quite naturally and without too much help from us, unless we are controlling the process. There are several different systems of composting that can be managed, like worm farming (vermiculture) and bokashi but they are for another day.
Very briefly, the organic waste we put into our bins starts to break down at varying rates, depending on what it is. (Compare a melon with a small tree branch. That watery melon is going to collapse within a couple of days. That branch could last for a couple of years at least.)
Once the break-down happens, though, the action speeds up. Initially, a variety of small creatures such as worms, slugs and insects, emerges for the buffet. They break down the plant tissue, making it available to a variety of micro-organisms – bacteria and fungi which then invade and start their own attack, converting the damaged tissue on a chemical level, using the released carbon and nitrogen to fuel their own activities. Worms, if present, will eat the bacteria along with a small amount of the vegetable matter, helping to pulverise the waste still further.
The carbon and nitrogen are obtained from two different types of ingredients. All organic waste is divided into these two categories, that which is rich in carbon and that which is rich in nitrogen. Carbon is derived from dried and dead plant matter like wood chips or straw, (called browns) while nitrogen is obtained from fresh ingredients like fruit, vegetables and grass-clippings.(called greens) Both are compost essentials, that is, they are two of the four essential ingredients that must be present for the composting process to succeed. The micro-organisms that are the driving force here use carbon as an energy source and nitrogen as a source of protein. An imbalance of these two elements will result in less than successful results.
So, along with the the essential carbon and nitrogen, what else is needed?
The four composting essentials are Nitrogen, Carbon, Oxygen, Water and the absence of any one of these will halt the process.
In the natural state this is what will happen in any pile. It will take some time, depending on the blend of ingredients and the temperature. It could take up to a year or even more.
So can the process be accelerated and is there any point?
Yes. the process can be hurried along by accelerated microbial action, known as Hot Composting and it is here that human intervention is helpful. (Note that heating your pile does not necessarily affect the level of nutrients in the end result. That is dictated by the quality of the original ingredients.) The aim is to raise the temperature in the bin to around 150^ F. and that is done by ensuring that there is a plentiful supply of oxygen. The benefits of this temperature hike (apart from the much shorter time it takes) include the destruction of pathogens that could be harmful to humans and plants and the ‘cooking’ of unwanted seeds that would otherwise sprout in your garden after your compost had been added. It can be quite difficult to raise a small domestic pile to these temperatures, but never fear. Your pile will get warm to some degree naturally, and your results will still be a great success.
We are looking at a real miracle of nature here and transforming your waste in this way can prove to be a wonderfully rewarding occupation. Try It!