(source: biorama.eu)
1. INTERFERING MATERIALS
Glass, metal, and plastics clearly do not belong in the compost heap – an explanation is unnecessary.
2. ASH
Coal ash is suitable for composting only to a limited extent. Ashes contain high concentrations of heavy metals, and the large quantities of potash increase the salt content of the compost, leading to a saturation of the soil over the years.
3. MATERIALS CONTAMINATED BY PESTICIDES
Although most pesticides are degraded through composting, these starting materials are hardly recommended. Too little is known about the combination of such agents and the danger of the degradation products. For an example, clopyralid (this substance is allowed as a herbicide not only for farming and plant nursing, but also for home gardens) is not degraded in the digestive system of a cow, nor in the subsequent composting of manure. It has phytotoxic effects even in the compost.
4. VACUUM CLEANER BAGS, STREET SWEEPINGS
The contents of vacuum cleaner bags and dirt from the road or the parking lot contain tire debris, air pollutants, etc. It is also not known what these materials introduce into the compost heap ecosystem.
5. LEATHER AND TREAT WOOD
Leather and wood are often impregnated with chemicals that assist in the preservation of leather or the preservation of wood. These also kill the soil life in the compost and can be difficult to degrade, as they were actually designed to withstand the forces of nature.
6. DOG, CAT, AND BIRD DROPPINGS
The droppings of these omnivores is usually contaminated with germs and parasites, which can become a problem if the compost sanitation is not sufficient.
7. ROOT WEEDS
Creeping thistle, couch grass or field bindweed are very tough, and oftentimes, only two to three centimeters long pieces of root already multiply magnificently in compost heaps. Roots that were painstakingly removed from beds should therefore left out to dry for about ten days in the sun; to see if they are still alive, make a cut into the roots, and only then put them into the composter!
8. WEED SEEDS
Weed seeds can only be destroyed in composting by the high temperatures in the hot rotting. If the weeds are weeded out before flowering, there certainly are no seeds, and young plants can be much easier to remove from the bed.
9. MEAT, SAUSAGE, BONE
May only be composted if a hot rotting takes place by the addition of fresh waste. In no case can large pieces or a whole animals compost! Avoid areas where there are problems with rodents. Meat residues should be covered to protect them from flies.
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