Environmental & Soil Microbiology

COMPOSTING

Written by MicroDok

Compost is simply defined as an organic matter comprising of plant, human or animal waste that have been decomposed and recycled or reused as a fertilizer to improve the fertility of the soil. Composts are very rich in nutrients, and it is widely used in several agricultural practices including but not limited to horticulture, formation of gardens and landscaping to improve the fertility of the soil in such scenarios. Composts are used in many areas over chemical fertilizers because of the ability of the former to retain the soil texture and biology unlike the latter. Composting is the controlled aerobic decomposition of organic matter by the action of microorganisms in the soil. It is natural process of recycling plant and animal organic wastes – in which both macro- and microorganism’s breakdown organic wastes into humus in the presence of aerobic organisms. A composter is a person that practices the act of composting. Composting is a simple way to add nutrient-rich humus which fuels plant growth and restores vitality to depleted soil. Composts are very rich in humus.

Humus is a complex dark or dark brown organic substance resulting from the breakdown of plant and animal material in a process called humification. The process of humification (which transforms organic matter into humus) can occur naturally in the soil, or in the production of compost. Humus is extremely important to the fertility of soils in both a physical and chemical sense; and it provides nutrients for plants and increases the ability of soil to retain water. Humus contains many useful nutrients for healthy soil, nitrogen being the most important of all. The composting process is dependent on microorganisms to break down organic matter of plant and animal origin into compost; and the microorganisms involved in composting includes bacteria, moulds, yeasts, actinomycetes and protozoa. Insects or arthropods such as beetles, worms, centipedes, snails and slugs are other macroscopic organisms or living creatures that can help aid the decomposing process of compost.

Composting is another important technology that can help us to reduce organic wastes in our environment while ensuring a green environment using similar wastes. It is a good environmental practice that is inexpensive and one which can help to keep organic wastes out of landfills – while enriching the soil and promoting sustainable agricultural practice in the process. It is an ancient practice that has been practiced since time immemorial to improve the fertility of the soil. Traditionally, composting involved piling organic materials of plant or animal wastes until the next planting season, at which time the organic materials piled up in the soil would have decayed enough to be ready for use in the soil. Composts are produced through the activities of aerobic microorganisms – that require oxygen, moisture and nutrients for growth and multiplication. The natural decomposition of plant and animal matter occurs at an accelerate rate when these conditions required for the growth of aerobic organisms (i.e. oxygen, water and nutrients) are maintained at an optimal level that supports their growth. As the plant and animal organic wastes are being transformed into composts or humus, they generate heat, water vapour and CO2 in the process.

Compost can be produced from a wide variety of feedstock or raw materials. The feedstock of composts includes raw organic materials of plant and animal origin such as leaves and food scraps respectively. Other feedstock of compost comprises of municipal refuse, dewatered sludge, paper, corn-cobs and straw. The benefits of composting are numerous. Composting conserves natural resources such as organic matter, nutrients and water; and it also help to combat climate change by decomposing organic wastes with oxygen driven by microbial activity, thus preventing the release of methane (CH4) gas into the atmosphere when plant and animal organic matter decompose in the absence of oxygen in landfills. Composting reduces water pollution by reducing the need for chemical fertilizers in our farms.

Composting improves the water holding-capacity of the soil; and thus reduces the leaching of nutrients in sandy soils. It also helps to prevent the formation of algae blooms in water bodies – which kills some aquatic life such as fishes. Composting is an environmentally-friendly way and a sustainable practice of improving the fertility of the soil, soil biology and the yield of plant crops. It is a good alternative to Landfilling and incineration especially in the disposal of plant and animal organic matter. Composting supplies a variety of macro- and micro-nutrients to the soil; and it improves and stabilizes the pH of the soil. Composing also supplies the required amount of organic matter or humus needed for a better plant root development. It improves the microbiota or biota of the soil. For example, the burrowing of earthworm into the soil is largely encouraged in the presence of sufficient amount of organic matter in the soil; and when this is the case, earthworms burrow or tunnel into the soil and in the process increases soil aeration and infiltration of water into the soil.

 

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