By Adelene van Zyl
Compost is decomposed organic matter, which aids in plant growth. Compost ensures that plants can easily absorb nutrients from the decomposed organic matter. It keeps your soil healthy and ensures that the soil contains all the necessary nutrients. It is therefore important to consider what you add to your compost heap to prevent over supply of one nutrient and under supply of another.
Composting is a cost-effective way to ensure healthy plant growth from a small garden to a commercial farm. However, it is important to understand that generating compost from a sustainable compost heap will take time. Give yourself a time-span of one year for the compost heap to fully become sustainable and generating good quality compost.
How to structure a compost heap:
You can use any large container, depending on how much compost you want over a long period. The type of container is also not set. However, do consider limitations of materials and modify your container accordingly. If you use a plastic container, ensure holes on the side for aeration. If you use a wood container, ensure holes underneath to allow water penetration and preventing rot. The principle of making a sustainable compost heap is to use what you have.
Layers of a compost heap:
There are different methods one can use to determine how many layers should be in the compost heap and what plant materials you should use in each layer. The following is a basic example and should be altered according to what you have available.
The first layer is your ‘browns’ which consist of branches and leaves which already appear brown. This can be divided as separate layers as well. Examples are mulch from a chopped tree, old branches and leaves.
The second layer is your ‘greens’ which consist of freshly cut grass, fruits and vegetables. This is the layer where you can use any plant-based material. Examples are fruit and vegetable peels, rotten fruits and vegetables, used coffee or tea bags and eggshells. Make sure that no yeast-based products are added in the compost heap, as this will cause mold growth and ruin the whole compost heap.
The third layer is soil or manure. This layer need not be as thick as the other layers, but it is necessary to optimize the breakdown of the other two layers. You can add these layers on top of each other as indicated on the figure.
How to take care of your compost heap:
It is important to water the compost heap at least once every second week. This will aid in the breakdown of organic matter. You should also mix your compost heap at least once a month to ensure proper breakdown of the plant material. If you want to speed up the process, you can add compost activator as indicated on its package. Compost activator is usually added once one set of the three layers are present or when there is a large amount of browns relative to the greens.