The microbial composition of compost varies depending on the decomposition processes. The success and functioning of each species depend on the amount of food available to them at each stage of development.
We mention only a few species that live in compost.
Actinomycetes
Actinomycetes are bacteria that resemble fungi and appear as gray, thread-like networks spreading through the compost mass like filamentous webs. They are among the first organisms to break down fibrous plant tissues such as cellulose, chitin, and lignin. They can decompose tree bark and paper, softening them for consumption by other organisms. Actinomycetes are also the basis for the production of streptomycin.
Bacteria
The most numerous and smallest organisms in compost help decompose plant and animal materials, releasing nutrients and serving as food for other organisms, including earthworms.
Fungi and mycorrhizal fungi – mushrooms
The most beneficial fungi are saprophytic species, which feed on organic matter and release humus. They can break down lignin and cellulose and produce nutrients that serve as food for earthworms. Mycorrhizal fungi are of major importance in agriculture, as they form symbiotic relationships with plants. It has been scientifically proven that earthworms contribute to the multiplication of mycorrhizal spores. This makes vermicompost extremely useful in agriculture.
Nematodes
They are microscopic worms that live in compost and play a role in digesting residual substances and microorganisms, also forming food for other organisms.
Protozoa
They feed on bacteria and are an important food source for earthworms, especially Eisenia fetida. Their numbers are determined by temperature and food availability, but they can form cysts and re-emerge when conditions become favorable again.
Rotifers
They are microorganisms known as “wheel animals,” creating vortex-like currents in water and soil by rapidly moving their tiny cilia, directing organic particles and other microorganisms toward their mouth. They also have the ability to form cysts.
Macroscopic residents
Black Ants They should be reduced by aerating the compost with a fork for several consecutive days.
Red Ants-Some earthworm species are protected by red ants, as these ants feed on predators of worms. The mucus layer on the worms’ surface prevents ants from attacking them. Earthworms also help ants maintain their nests, as they feed on fungi that cause decay in ant colonies. Although this relationship may appear beneficial, in most cases red ants attack earthworms and other beneficial insects. Maintaining adequate moisture, creating an oil barrier around compost containers, or using a 50% boric acid + 50% sugar mixture along ant pathways can help keep them away from compost. plasat in calea furnicilr, le va tine departe de compost.
Bathroom moth flies
Small moth flies (about 4 mm), with larvae reaching around 5 mm. They are considered beneficial for composting because the larvae help decompose organic matter.
Centipedes
They are generally carnivorous and nocturnal. They do not cause significant damage when present in small numbers.
Colembola
They are about 2 mm long and have pincers at the tail end. They can reach up to 100,000 per cubic meter of soil and are highly beneficial in composting, as they accelerate the decomposition process.
Fruit Flies
They are beneficial, but their population must be controlled.
Multipedes
They are useful for composting as they structure and aerate the compost through their mechanical movement, making it more favorable for bacterial activity.
Tetranychus urticae (spider mites)
Beneficial for composting – they feed on fungi, spores, nematodes, collembola, other mites, and small insects.
Fungus gnats and sciarid flies
They look like mosquitoes but are not harmful. Sciarid flies are small black flies, about 3 mm long, with long antennae and legs. Their larvae are transparent, reaching up to 5 mm, and feed on fungi. They are not harmful to compost.
Potworms (Enchytraeidae)
Small white worms – sometimes confused with nematodes ranging from 1–50 mm. They are beneficial in composting, feeding on plant fragments, fungi, and silica granules, contributing to the decomposition process.
Pseudoscorpions
They are about 4 mm in size and do not have a tail like scorpions. They feed on other organisms such as plant lice, collembola, and small insects.
Snails and slugs
They help decompose plant material, and their secretions stabilize soil moisture, contributing to improved soil structure. Enzymes produced by snails break down cellulose, creating food for microbes. There are seven species harmful to plants that can proliferate when compost is spread on the soil. It is advisable that compost does not contain snails and slugs.
Spiders
Good to keep away from compost.
Woodlice
There are 37 species, including 5 common ones. They feed on dead vegetation, wood, fungi, and algae, and find their ideal habitat in compost. They are highly beneficial, providing pre-digested food for microbes. It is recommended to have them in compost and even encourage their presence by creating suitable conditions, such as adding a decaying log (e.g., a stump) to the compost.