In principle, all organic matter is compostable. However, some materials only decompose very slowly or cause other problems, so there are a few exceptions. Some materials shouldn’t be added too much to the compost:
- Cooked vegetable and fruit waste or leftover meat often attract a lot of vermin
- Lawn clippings and bark mulch make the compost sour; Grass clippings also often quickly form an air-impermeable layer
- Tea and coffee sometimes contain zinc and copper compounds
- Wood and shrub cuttings take a long time to decompose
- Printed papers can contain toxins
- Sick parts of plants or materials that have been contaminated with pesticides, e.g. cut flowers from nurseries or peel of citrus fruits
Weed should be weeded 14 days before commercial composting Australia or parched in the sun so that the seeds and roots lose their ability to germinate. Root weeds such as couch grass or bindweed must not be placed on the compost, as they will sprout again from the roots.
Ideal humus is obtained when the ratio of carbon (C) and nitrogen (N) in the compost is correct. A good C: N ratio is between 20: 1 and 40: 1.
What happens in the compost?
The decomposition in compost has 3 phases:
Pre-rotting , degradation phase : First of all, easily degradable substances are broken down . Bacteria convert a lot of substances quickly. Heat develops (approx. 50 – 65 ° C), which kills germs and weed seeds.
Main rot , renovation phase : The temperature drops to 30 – 40 ° C. Mushrooms do the main work, the metabolism slows down.
Maturity phase , cooling phase : substances that are difficult to decompose, such as lignin, are broken down. The temperature drops to approx. 20 ° C. Worms, woodlice and other visible living things are added.
Use of compost
The finished compost soil is spread over the cultivated areas and forms a fertile humus layer. Half-ripe or fresh compost (1/2 year old) can be added directly to the beds as mulch or to improve the soil. Fresh compost should not be added to root vegetables, onions, and cabbage, however, as it often attracts vegetable flies. Ripe compost (1 year) is nutrient-rich fertilizer:
- Vegetables approx. 1-3 l / m² per crop
- Lawn approx. 1-2 l / m² per year
- Perennials approx. 1-2 l / m² per year
- Woods approx. 1 l / m² per year
Also for potting compost is mixed. For example for sowing: 1/3 ripe compost, 1/3 garden soil, 1/3 sand; 1/3 ripe compost and 2/3 garden soil are used for potting soil.
Before the compost is used in potting soil, its tolerance to plants should be tested . In addition, the compost should only be used when needed, as excess nutrients are washed out unused.