Composting: what it can do and how it works
Whether in central composting plants or in your own home: composting has many advantages. Among other things, it serves to form humus and can maintain and even improve soil fertility. Most of us know far too little about the impressive process and associate compost with unpleasant smells. You want to know how composting works, what can end up on the heap and why professionally operated compost doesn't smell at all? Then you should read on now.
What happens to our organic waste?
What happens to organic waste is regulated by the Recycling Management Act, the Organic Waste Ordinance and the Fertilizer and Fertilizer Ordinance. The largest proportion of organic waste from private households ends up in the organic waste bin and is then fermented and/or composted in central plants. The valuable fertilizer is used to improve the soil, especially in agriculture and horticulture. In principle, all garden and kitchen waste from private households must be left to the public waste disposal authority. One is only released from this if professional and proper self-recycling is guaranteed: Self-composting must be carried out professionally and in an environmentally friendly manner all year round .
Create compost - what do I have to consider?
According to the Federal Environment Agency, self-composting is not an alternative to separate collection, but it is a sensible addition when operated professionally. Since there are hardly any specifications for use in your own garden, here are a few helpful tips for you. Non-professional private composting can even be rated as ecologically disadvantageous, especially with regard to greenhouse gas emissions, soil over-fertilization and endangerment of groundwater. You can build your own compost and save on organic fertilizer and organic bins in the future. The compost heap is not only suitable for disposing of garden and kitchen leftovers, but also transforms waste over time into humus (humus = part of the soil that is formed from dead organic substances).
The right location
The compost location should be chosen carefully: in the semi-shade, sheltered from the wind, not on stone, concrete or asphalt, not in a pit and preferably easily accessible. Once you've found the perfect spot, you're good to go.
After you have loosened up the subsoil, you can start layering. The first layer should be branches and twigs, followed by a layer of leaves, smaller branches and some grass clippings, followed by garden and kitchen waste. The materials to be composted should be broken up and mixed well. By the way, diversity is very important.
The optimal conditions
The compost should always be moist, but never wetter than a squeezed sponge. If there is a lack of moisture, many microorganisms go into a rest period, which slows down the rotting process. Adequate ventilation is also important. Therefore, do not use a container that is closed on all sides. Regular repositioning is also required. It contributes to aeration and mixing and accelerates the ripening process.
How organic waste becomes compost
Once your optimal compost has been created, degradation processes begin immediately. The so-called "rotting" causes the degradation and conversion of organic substances. Tiny little creatures get to work. Composting means creating the best living conditions for the oxygen-loving microorganisms: They need oxygen, water and insist on a comfortable temperature.
First, rapidly degradable materials are processed. It gets really hot - in the fresh compost the temperature quickly rises above 70° C. After that it gets a little cooler again and the microorganisms migrate. The so-called cold rotting takes place and the humus production starts.
The more diverse the mixture of waste, the better the rotting process and the more valuable the compost will be in the end.
What can end up in the compost:
Anything that contains carbon in a biodegradable form can also be composted. However, not all substances are also suitable for your own composting in the garden. Here is a small overview for you:
- leftover fruit and vegetables
- tea and coffee grounds
- dry lawn clippings, tree and hedge clippings
- easily compostable leaves (e.g. linden, willow, maple, hazelnut)
- old earth
Suitable in moderation:
- Plant-based litter for small animals
- Paper, cardboard, small amounts of kitchen paper and newspaper
- fresh lawn clippings
- citrus fruits
- Ash from untreated wood
- treated wood
- coated paper
- diseased or infested plants
- leather, metal and glass
- feces of carnivorous animals (e.g. dog feces)
Since some waste (e.g. cooked food, meat, bones) attracts vermin, it is better to dispose of it in the organic waste bin.
Does compost stink?
With proper care, compost does not stink, but smells of fresh forest soil. However, if it is not well ventilated, the waste rots and there is an unpleasant smell. The bacteria that develop in this way form the foul-smelling gases ammonia and hydrogen sulfide. The climate-damaging gas methane can also be produced. Professional care and regular digging not only accelerates decomposition, but also largely eliminates the risk of methane formation. The right care is not only good for our nose, but also important for the climate.
The worm box - a small compost for the office
No garden? No problem. You can easily get nutrient-rich soil on the balcony: with a worm box. As a mini compost, it also turns vegetable waste into worm castings, which you can use as fertilizer for the window boxes.
First you need a wooden box. You can build these yourself from pallets or buy them ready-made. Holes of about 6 mm must then be drilled into the base plate. Of course, a worm box also needs worms. You can get them in specialist shops. The larger the box, the more worms you need. It is best to get advice on this on site.
Line the wooden box with damp paper and put a layer of garden soil on top, followed by some leftover vegetables - not too much kitchen leftovers, please; around 200 g daily are sufficient at the beginning. Now the worms get to work.
After three months the first compost is ready. To use it, lure the worms out of the compost by tipping it to the side in the box. You then put new kitchen leftovers on the empty side, into which your animal helpers will have moved after about four weeks. Then sieve the worm-free compost well - done.
Caution: In winter, the worm box must be in a warmer place. Your roommates do not like frost.
In our Leipzig office we have our own worm box from wurmkiste.at . Since our product packaging can be composted at home, we can throw it directly for the worms to eat :p. You can also dispose of your packaging in the compost, but please do not overdo it. Balance is key - also on the compost heap and in the worm box.