Get to know the basic science of composting

Get to know the basic science of composting

At BiobiN South Africa, we talk a lot about composting and extracting value from organic waste. As we keep the conversation going, we thought it may be a good idea to understand the basic biological and psychical processes that take place when we put our food waste into composting units.

So, what exactly happens?

Aerobic decomposition: sounds like a heavy bit of jargon; not really. As soon as we add our organic waste, microorganisms that thrive in oxygen-rich environments get to work. We turn and add oxygen to our compost units to promote an aerobic environment for these valuable microorganisms to start breaking down waste. In an aerobic composting environment, the composting process is most efficient and produces the least amount of odour.

Anaerobic decomposition: even though we want our aerobic micro-friends to do most of the work, we do want some anaerobic biodegradation to take place. Aerobic microorganisms, this time living in conditions with little to no oxygen, break down more durable waste material. Careful control of the conditions within a composting unit will ensure that the most efficient ratio of aerobic and anaerobic conditions is present during the different phases of the composting process.

Thermal phases: Compost goes through three thermal phases: the initiation phase, the thermophilic phase, and the maturation phase. During the initiation phase, there is a rapid growth of microorganisms which will start to consume the waste and generate heat as a result of their activity. Eventually, this phase comes to an end when the increase of heat is too much for their survival. Next, heat-loving thermophilic microorganisms take over. During this stage, most of the composting happens at a temperature around 70 degrees Celsius, and many of the harmful pathogens are removed. During the last phase, the temperature of the compost decreases, and a lot of the microbial activity slows down as most of the waste has been converted to compost. It is now ready for your garden!

What is the outcome? We all know that compost is good for your garden, but what is in it that makes it good? The answer is a bunch of beneficial nutrients and minerals such as nitrogen, copper, phosphorus, and zinc. Good quality compost will contribute to plant health, soil structure, and make your plants more resistant to disease.

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