Worm compost, also known as vermicompost, results from using worms to break down food scraps and other organic matter. Brandling worms (Eisenia fetida), European nightcrawlers (Eisenia hortensis) or red worms (Lumbricus rubellus) are added to compost, where they consume organic waste and then excrete it in the form of nutrient-rich castings. In addition to its soil enrichment value, worm compost offers other environmental and agricultural benefits.
Worm compost offers several environmental benefits. First, worms are capable of breaking down organic matter like food scraps, which means less garbage being sent to landfills, not to mention the resources used to remove and transport waste. In addition, worms are a natural soil detoxifier capable of breaking down hazardous elements like lead, cadmium and other heavy metals. The use of worm compost as a soil enhancer also benefits the environment because fewer synthetic chemical fertilizers are manufactured and used in gardens.
Its use to enrich garden soil is another benefit of worm compost. Not only does worm compost improve soil's nutrient levels, but it also benefits the soil's physical composition. Worm digestive juices help to break down soil and organic matter, making essential macronutrients -- nitrogen, phosphorus and potassium – more readily available to garden plants. Besides the macronutrients, more beneficial copper, iron and zinc is found in worm compost than in animal manure. Worm compost also increases moisture and helps soil to retain these vital nutrients.
Another benefit of worm compost can be increased yields of garden vegetables and flowering plants. Tomatoes, peppers and marigolds grown with worm compost added to soil can bear more fruit and flowers than when traditional chemical fertilizers are used. Increased yields of wheat and sugar cane have also been demonstrated.
Worm compost also helps to protect plants from the threat of insect pests and disease. This benefit is related again to the worm's digestive system, which adds beneficial microbes to the soil. These microbes then reproduce quickly and work to combat microorganisms in the soil that cause disease and weaken plants, making them more susceptible to insect infestation. Worm compost also reduces problems with harmful parasitic nematodes and arthopod pests.
Worm composting is more time-efficient than traditional composting, producing useable worm compost in just three to six months, depending on the size of the compost bed and the number of worms used. If properly cared for and provided sufficient waste, a thousand worms can eat up to 1 pound of waste a day.
- Purdue University Extension: Household Composting With Worms
- New York Times: Worms Produce Another Kind of Gold for Growers
- Cornell University: Worm Composting Basics
- University of Hawaii Sustainable and Organic Agriculture Program: Vermicompost Research Update 2009
- Utah State University Extension Sustainability: Vermicomposting
- Penn State University Cooperative Extension: Vermicomposting Animal Manure
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