For thousands of years, worms have played a vital role in farming because of their incredible ability to enrich nutrients in the soil.
Worm castings are among the most beneficial natural products farmers can use, because they promote plant growth and overall health without the negative effects of synthetic fertilizers.
According to Denali BioSolutions, worm castings are “tiny, roughly elliptical worm manure particles loaded with beneficial bacteria, fungi, protozoa and nematodes capable of rebooting the soil food web and all its functions and benefits.”
Denali BioSolutions (www.denalibiosolutions.com) is a Wisconsin-based producer of organic, commercial worm castings. These important, all-natural microorganisms help create a perfect medium for breeding hardy plants.
“If you’re not using chemicals, then you don’t get a chemical taste,” says Kelan Moynagh, owner of Yelm Earthworm & Castings Farm (www.yelmfarm.com) in Washington. “People who are connoisseurs prefer high-quality bud that is grown in completely organic soil, and high-quality usually means using castings. The thing about castings is that it gives everyone a green thumb.”
There are numerous benefits of using castings, says Denali BioSolutions market specialist Adrian Ramirez.
Plants that grow in soil with worm castings benefit from “faster seed germination and plant emergence, and also promote early and consistent root development and growth,” he explains.
Bacteria is an important component in castings, helping provide nourishment and fight diseases. Ramirez says nitrogen-fixing bacteria are the most important for soil because they convert atmospheric nitrogen into a form plants can utilize during photosynthesis.
Protozoa also aid in repressing diseases and releasing nitrogen that plants can benefit from when they consume bacteria, fungi and other protozoa in the soil. While some fungi in castings help decompose dead organic matter, like manure or leaves, Ramirez explains “mutualists (mycorrhizal fungi) colonize plant roots and are responsible for solubilizing phosphorus and transporting soil nutrients into the plant.” Phosphorus helps stimulate root growth, increases resistance to diseases and improves the overall caliber of the crop.
Additionally, nematodes play an impactful part in healthy soil by preying on unwanted or overpopulated organisms. In doing so, nematodes release good bacteria and fungi back into soil which benefits the plant.
Other benefits of castings include increased drought resistance and more consistent pH levels.
They’re also completely safe to use around children and pets, and they have longer lasting effects than synthetic fertilizers.
Julie Fritts, owner of 3 in 1 Worm Ranch (www.3in1wormranch.com) in Washington, stresses the importance of not using too many worm castings. Believe it or not, she says, using too many castings can have a negative impact on plants.
“Your plants don’t grow as well,” she says. “I did experiments where I tried going pure castings, and nothing came up.”
Fritts suggests a soil-to-castings ratio of about 3:1. Depending on the application and soil, some sources recommend a 4:1 ratio.
While some farmers elect to raise their own worms and harvest castings, it’s typically easier and more reliable to simply have them shipped in bulk. For example, Denali BioSolutions ships worm castings and other fertilizers and compost products in sizes up to 2,000 pounds.
Fresh, healthy castings are key for farmers to get the most out of their plants and soil.
“Our OMRI Listed worm castings are produced in very high volumes and under strict quality-control methodology to achieve impeccable biological and nutritional consistency from batch to batch,” says Craig Fink, president of Denali BioSolutions.
“We want to help cannabis growers achieve their goals in a cost-efficient manner by offering effective products and sustainable programs to support their operations from inception to perpetual harvests,” Fink adds.
Moynagh explains that one of the ways people can tell worm castings are healthy is their odor. He says good worm castings don’t stink; they should “smell like the earth.”
Another indicator is using springtails, which are small, white flea-like insects. To the naked eye, they look like small white dots.
“One way you can determine if the soil is healthy is to put springtails on it,” Moynaugh says. “If they skedaddle or die, you know you have a toxin. This is the way that some scientists have been able to determine the toxicity of soils.”
Worms do the dirty work of nature.
“We’re using worms to process manure,” Moynagh says. “More specifically in our case, dairy manure and horse manure.”
These worms in particular are commonly referred to as red wigglers. Unlike an average garden worm, red wigglers like to live in organic matter on the surface of the soil, instead of beneath it. “Because they live on the surface, they can handle a wide range of environmental conditions like moisture, pH, food levels and temperature,” Moynagh says. “And all they like to do is eat all day long.”
Although there are a variety of processes that can be used to harvest worm castings, Moynagh and his crew start out with a row of worms, feed them a layer of food and wait for them to eat through it.
“We can tell when they’re finished by looking at the row,” he says. “When the row is initially fed, it’ll have a rough appearance.”
Once the worms are done eating, the manure smooths out and takes on what Moynagh describes as a “sand dune appearance.”
Then the castings are ready to ship to farmers throughout the country.