Production and use of vermicompost
The value of vermicompost for cultivated soil
Vermicompost is becoming an effective solution for soil improvement and crop yield enhancement, chosen by many farmers in sustainable agricultural production. This dark brown organic matter, a product of earthworm digestion, contains superior nutrient levels: 5 times more nitrogen, 7 times more phosphorus, and 11 times more potassium than conventional soil. As a result, vermicompost helps improve soil structure, increase soil porosity, enhance crop quality, and extend post-harvest shelf life.
Production model at Sonoma Valley Farm
In Sonoma County (California, USA), Jack Chambers' Sonoma Valley Worm Farm is a prime model on a commercial scale. Each month, the farm produces around 35,000 pounds of worm castings. Mr. Chambers stated that since 1992, the model has helped recycle over 1.8 million tons of organic waste, keeping it out of landfills and providing earthworms for home composters.
The main raw material for production is manure from organic dairy farms. The waste is first hot-composted to kill pathogens and weed seeds, then cooled and fed to the worms twice a week. At the farm, 10–12 million worms work continuously in composting beds measuring 80 feet long and 5 feet wide. Once the manure has fully decomposed, the bottom layer is cut away, collected and screened to remove worms before packaging.
Besides organic compost, worms are also harvested for commercial sale. Chambers noted that many of his clients are prominent Napa Valley wineries, and even celebrities like Oprah and Martha Stewart.
Household earthworm farming
Not only suitable for farm-scale operations, the earthworm (redworm) farming model can be applied right in households or small gardens. According to expert Meghan Elliot, residents only need to prepare one pound of Eisenia fetida redworms (approximately 1,000 worms) along with two plastic bins, newspaper, vegetable scrap residues, and household food leftovers to start composting.
The process is quite straightforward: drill air and drainage holes in plastic bins, stack two bins, line them with moist newspaper as "bedding," bury some food scraps, and add the worms. The worms will gradually adapt to their new environment and can consume an amount of food equal to their body weight daily. Over time, households can harvest vermicompost and worm tea to fertilize crops, reducing the need for chemical fertilizers.
According to experts, developing earthworm (perionyx excavatus) farming not only brings benefits but also economic value: recycling organic waste, reducing the amount of waste sent to landfills, supporting sustainable farming, and improving income for rural people.