The micro-herd is the microorganisms, including bacteria, fungi, and other microbes, that play a crucial role in the decomposition process.
These microorganisms are the active players in the composting process. They feed on garden and kitchen scraps and turn that discarded organic material into dark, nutrient rich humus. As the micro-herd does its work, the compost pile heats up facilitating the decomposition process.
The microherd includes different types of microorganisms essential for composting, such as decomposer bacteria that break down complex organic molecules, nitrogen-fixing bacteria that play a role in nutrient cycling, fungi like molds and yeast, and other microbes.
When yard waste or vegetable scraps are thrown into a compost pile, the decomposer bacteria are the first to act upon the material. Their job is to secrete enzymes that breakdown the complex organism into simpler byproducts so that other microorganisms can do their work.
Through this decomposition process, these bacteria release essential nutrients – nitrogen, phosphorus, and others – back into the soil. Once these nutrients are broken down into their simpler forms, plants can take up the nutrients through their roots.
Plants cannot survive without nitrogen. Nitrogen is responsible for cell development and growth and chlorophyll production. Nitrogen-fixing bacteria make atmospheric nitrogen available for the plant. Seventy-eight (78%) percent of the earth’s atmosphere is made up of nitrogen but it is not in a form that plants can use. It is the responsibility of these nitrogen-fixing bacteria to establish a presence in or on the plant roots of legumes, such as peas, beans and clover, through a symbiotic relationship with the plant. Other non-legumes plants, such as grasses, shrubs and trees rely of free-living nitrogen fixation for their nitrogen supply. Free-living nitrogen fixing bacteria do not create a symbiotic relationship with the plant and instead live freely in the soil making itself available for all plants.
Like decomposer bacteria, fungi breaks down complex organic matter into simpler molecules making them accessible to other microorganisms or plants. Fungi will create a network of thread-like structures within the compost pile. This network is called fungal mycelium and it helps improve the structure of the compost, aides in aeration and water retention. As we know, proper aeration is required for a healthy compost pile.
As you can see, without the micro-herd, organic matter would continue to exist in a less decomposed state, and the recycling of nutrients essential for growth would be hindered.