Composting is a process of transforming organic waste into a rich, high-quality, 100% natural soil: compost. It makes the soil lighter and saves fertiliser, soil and water. It also reduces our kitchen and garden waste, and avoids the need to take it to the waste disposal centre to get rid of it (btw, did you know that food waste in dumps produces methane gas?).
Under favorable conditions, the organic matter in the pile is broken down by micro- and macro-organisms (earthworms, insects, bacteria, fungi, etc.) and transformed into nutrient-rich humus.
These reactions require oxygen and generate heat. The temperature at the heart of the compost increases to 50 to 70°C as it decomposes, and then decreases.
The larger the pile, the greater the temperature rise and the faster the composting process.
Where to create your own compost ?
A good location for a compost heap is in the shade, as it dries out if it is too hot. Remember to water it if it is too dry and to cover it to prevent leaching.
You can use commercial compost bins or build your own with wooden planks or wire mesh. Be sure to leave the bottom of your compost bin in contact with the soil, as this is a direct source of micro-organisms (such as earthworms) that are essential to the success of your compost.
For those who want to compost a small amount of waste, you can dig a hole directly in the ground. Dig a trench 20cm deep and as wide as the amount of waste you want. Cover with straw or black plastic and keep moist as for normal compost. There are also balcony composters for those without a garden.
For those living in urban areas, and that don't have the time and/or space to have the pile at home, visit sharewaste.com, the website where you can "meet neighbours, recycle organics and build soil".
Keep an eye on the aeration and humidity level !
Aeration is a key factor as composting is an aerobic process. Poor aeration of the compost heap is the main reason for slow, partial, uneven or poorly smelling composting. It is estimated that air should occupy at least 50% of the volume of the pile. Therefore, mix the pile as often as possible (every 4 to 6 weeks) to aerate it well.
The first mixing should only be done 2 to 4 weeks after the waste has been placed in the heap. In this way, you avoid lowering the temperature and preserve the activity of the bacteria.
It is important that you check the moisture content of your compost. To check that it is satisfactory, squeeze a handful of compost in your hand. If beads of water start to appear, the moisture content is good. If there is a lack of moisture, cover the mixture with a tarpaulin, and if there is too much, stir and lift the tarpaulin to air the mixture for a moment.
When is the compost ready to be used ?
It can be mature after 3 to 6 months in spring/summer or 6 to 9 months in autumn/winter if it is well insulated and turned regularly. Some composters can even produce quality compost in just 4 to 6 weeks! Compost is ready when it smells like forest soil, humus and crumbles easily. Remove it from the base and incorporate it at the foot of the plants or in the planting holes. Be careful not to bury it but to incorporate it superficially.
You'll see how rewarding it is to see your "waste" become something valuable, and maybe even your relationship with the food and the land will change!