Vermicompost is a nutritive organic fertilizer enriched microbiologically-active peat-like material, and is commonly used for management of organic wastes by decomposition and humifiction of biodegradable organic wastes carried out by microbes present in the soil and gut of earthworms. Vermicomposts improve plant growth and development beyond that normally observed from just soil nutrient transformation and availability. These increases in plant productivity have been attributed to improved soil structure and soil microbial populations that have higher levels of activity and greater production of biological metabolites, such as plant growth regulators.
vermicompost could promote early and vigorous growth of seedlings. It has been found to effectively enhance the root formation, elongation of stem and production of bio- mass, vegetables, ornamental plants, etc. More available plant nutrients and microbial metabolites may be released into the growth media because earthworms may stimulate microbial activities and metabolism and also influence microbial populations
Intense use of agrochemicals, including inorganic fertilizers and pesticides, since “green revolution” of 1960s boosted crop productivity but at the expense of environment and health. This led to the exploration of alternatives to chemical fertilizers and pesticides among scientific communities. Several researches on potential of earthworms to degrade solid organic matter and analysis of worm cast have demonstrated the use of earthworm cast (vermicompost) in sustainable agriculture. Vermicompost is a nutritive organic fertilizer enriched with plant available forms of macro (Nitrogen, Phosphorus and Potassium) and micro (Iron, Copper, Zinc, etc.) nutrients, beneficial soil microbes; nitrogen-fixing and phosphate solubilizing bacteria, actinomycetes and plant growth regulators like auxins, cytokinins and gibberellins. In addition, composition of vermicompost show antagonistic ability against soil-borne pathogens thereby improving plant health.
After earthworms digest organic matter, they excrete a nutrient-rich waste product called castings. As food passes through their digestive tract, worms secrete chemicals that break down organic matter into sustainable nutrition. These chemicals, excreted with their castings, comprise vermicompost, which improves soil texture, structure and aeration. From the Latin “vermi,” which means worm, vermicompost offers nutrients that are immediately available to plants. It can be applied as mulch, incorporated as a component in potting mixes or brewed in water as a compost tea liquid fertilizer.
Earthworms leave soil 5 to 11 percent richer in the essential plant nutrients of nitrogen, phosphorus and potassium than when they first ingest it. As an organic fertilizer, vermicompost is a substitute for synthetic fertilizer in soil-enriched vegetable transplant potting mixes. As a soil conditioner, vermicompost is superior to traditional compost for its ability to improve soil structure and increase its water-holding capacity, according to the University of California’s Project Compost.
Increasing Plant Growth and Yields
Organic farmers value nonsynthetic fertilizers for their minimal impact on local ecosystems. When these fertilizers also produce faster plant growth and higher crop yields on tomatoes, peppers and strawberries showed that plants fertilized with organic vermicompost significantly outperformed the same crops fertilized with inorganic, synthetic chemicals research revealed vermicompost tea fertilizer yielded dramatic plant growth rates and crop yields of up to 50 percent.
Damping off is an infectious plant disease caused by seedborne pathogens such as Pythium, Phytophthora and Rhizoctonia species. Seeds rot before successful germination or post-emergent seedlings prematurely wilt at the soil line from infected lesions. Conventional disease prevention uses synthetic chemicals to pretreat seeds. A 2010 Cornell University research project using cucumber seedlings proved consistently successful disease suppression of Pythium damping off when active vermicompost was used in synthetically pretreated seeds. Heat-sterilized vermicompost did not effectively manage disease.