By Christine Morgan, ND, Somervell County Master Gardener Intern
What is it and why is it important?
Let’s start with some definitions. What is vermiculture? It is the raising of earthworms under defined and/or controlled conditions. In this application, it is a cultured organism. The culture of earthworms is known as vermiculture. Vermicomposting is defined as using earthworms and microorganisms to convert organic waste into black, earthy-smelling, nutrient-rich humus. Humus is a nutrient-rich, complex, highly stable material formed during the breakdown of organic matter.
There are two different forms of vermicomposting. The first is a compost pile outside consisting of dead plants, leaves, green grass clippings, small twigs and herbivorous animal (cow, horse, goat, sheep, rabbit) manure. Poultry manure can be used sparingly from clean flocks and if it is aged. Green poultry manure can be very strong and for other reasons is not recommended as the primary manure. The best sources are from only plant eating animals. Some people also add kitchen waste from fruit, vegetables, greens, and egg shells. Manure from dogs, cats, pet rodents, and pet birds should NOT be included. Meat, bones, shellfish waste, and dairy products should be excluded also.
The second form is indoor kitchen waste only composting. People use this method to recycle kitchen garbage, make a wonderful soil additive and fertilizer, and raise earthworms to sell and for fishing.
Worms need a constant temperature (between 59-77*F) to be happy and healthy. Below freezing will kill them if they are exposed to 32*F temperature or lower. Outdoor worms burrow deeper as it gets hotter in the summer (above 86*F), and move closer to the surface in the Fall and Spring. In the cold of Winter, they again move to warmer quarters whether that is the center of a warm, active compost pile or deeper in the ground. Kitchen waste composters do best in an indoor environment like a basement or cooler room, especially because of the fact that their habitat is constantly being opened and changed…i.e. influx of new waste material every week.
Temperature, moisture, acidity, and ventilation are very important factors to take into consideration if you want worms to work for you. Worms “breathe” through their skin, which must be moist for exchange of air and excretion of waste (castings/worm manure) to occur. Yes, worms can drown in too much moisture/water. They are fairly tolerant of a wide range of acidity. On a 14-point PH scale, 1 being very acid and 14 being extremely alkaline…PH5 to PH9 is suitable. So they like a slightly acid environment, more to the acid side than alkaline. Ventilation is important because they need oxygen to “breathe” and do their “work”. They produce carbon dioxide just like we do, and use oxygen in many of their bodily processes. Breaking up soil, digesting waste matter is what they do. Sort of like tiny plows, breaking up and aerating the soil to help plant roots grow and spread.
The next important piece of information is the fact that there are two different general types of earthworms. Who knew? We have “earthworkers” and “composters”.
First, let’s discuss “earthworkers”. These are the worms you mostly find outside in soil, gardens, and under planters, buckets, etc. They are the “soil-dwelling” species. The scientific name for one of the most prolific species is Lumbricus terrestris. They don’t process large amounts of organic material, they don’t reproduce well in confinement (captivity), and it makes them nuts if someone digs around and messes with their burrow system. Their common name is “nightcrawlers”. This worm is the most studied of the 4,400 species of earthworms currently named. Another trivia fact…none have been found in Australia! They require large amounts of soil or decaying material and like it cool (50*F). Digging burrows and knowing the intricate burrow system is very important to them. They have a territory and don’t like moving day. They play an important role in soil fertility. They perform important soil mixing functions as they travel between the surface and several feet below. They take organic materials into deeper layers of the soil, mix it with subsoils that they consume in their burrowing activities, and bring mineral subsoils to the surface when they deposit their casts (worm poop). The burrows aid in soil aeration and in water retention by increasing the rate at which water can penetrate the deeper soil layers. In plant beds, near water faucets, or garden spaces they are free to burrow and work their magic.
The second general category of worms is the “composters”. Composters are worms that consume and process massive amounts of organic material. They reproduce quickly in confinement, and tolerate the disturbance caused by adding bedding and burying new waste. They don’t really care about burrows…they are more concerned with food, eating, and reproducing. The scientific name for a large species is Eisenia fetida. Their common names are Redworms, Tiger Worms or Red Wigglers. Their natural habitats are manure piles, compost piles, or decaying leaves in heavy brush or forest type habitats. They tolerate a wide range of temperature, acidity, and moisture conditions. They are tough worms and withstand handling well. They tolerate being shipped through the mail and living in plastic bait containers without dying. Like I said, they are tough. They like to live and work on the surface in upper layers of soil or bedding, perfect for living in bins and adding new layers of organic material on a regular basis. Another composting species, Lumbricus rubellus, has the potential for doing double duty as a composter and earthworker.
Interesting Worm Facts
Earthworms don’t have any teeth, but they have a gizzard like a chicken; grit helps them grind and process organic matter, which is their food. They have no eyes and can’t see…but making cartoons of worms with no eyes seems wrong somehow… Worms are hermaphroditic. Worms have both ovaries and testes, so they can decide who they want to be! They make cocoons with the egg in it and fertilization takes place in the cocoon. Usually 2 or more worms hatch from one end of the cocoon. It takes two worms to fertilize an egg in the cocoon.
Worms are very important in farming and gardening. They are hard workers in breaking down decaying matter and making soil more beneficial to plants. We know when we see earthworms in our gardens, that the soil is rich and probably healthy to support plant growth. If you have no worms in your soil, I suggest getting a soil test ASAP from your county agent to find out why. Recycling kitchen waste and composting outside is a “green” action that helps the earth, your garden and your plants. Worms are an important link in the cycle of life. Now you know more about worms than your neighbor!
References:
www.aggie-horticulture.tamu.edu/beneficial
Worms eat by Garbage by Mary Appelhof
www.easttexasgardening.tamu.edu