What’s Underneath Your Garden?
Written by: Brian Banh
Cultivating your garden into beautiful greens, reds, or any color you can think of takes hard work and dedication. When tending to the garden seems unbearable some days, just know that there are so many components supporting your garden to make it as bountiful as it is: the sun providing much needed light for growth, water to sustain the plants, nutrients in the soil to make the plants strong, and wormy friends traversing underneath. The tube-like invertebrates in particular are one of your best friends in the garden, and although they don’t seem like much, their presence in the soil contributes to the healthiness of your garden space.
Worms play such an important role in our soil that farmers and gardeners see their presence to determine the health of their soils. They are considered our soils’ engineers where they alter the physical, biological, and chemical properties to create a healthy foundation for our plants to grow in. Physically, they change the soil structure by simply excavating through it. The tunnels they create underneath create macro pores. These pores aerate the soil and allow water to filter through easily. The loosened soil also allows roots to penetrate and spread throughout the soil profile.
Biologically, worms are one of the main contributors to decomposition, an essential natural process to recycle organic material back into the earth. They do this by shredding large plant litter on the surface layer. These fragmented pieces are then accessible for fungi and bacteria to decompose further and unlock the nutrients from these pieces. Some worms even bring these particulates down to layers close enough for plant roots to uptake from.
Finally, the unlocked nutrients from the fragmented litter changes the chemical composition of the soil. Processing the litter through their digestive tracts, their castings leave the soil more nutrient-rich than what came in. Their castings contain nitrogen, phosphorus, magnesium, potassium, and calcium, and directly benefits microbial growth in the soil. Their nitrogen-rich casts fertilize the garden, and keep plants happy and healthy.The nutrients that come from their castings are so beneficial and potent that farmers sometimes dub it as “black gold.” Even in our own PICA garden, we utilize a vermicompost bin (aka worm bin) to produce exactly this!
Ways to Care for Your Worms:
If you’re now thinking about caring for worms in your garden, here are some places to start. There are some garden and farm activities that are currently damaging worm populations, and here are the big ones: heavy tillage operations, overstocking, and chemical fertilizer overuse. Heavy tillage operations are harmful to worm populations because the tilling agitates and aerates the soil too much; heavily aerated soil reduces the amount of organic matter available for worms. To address this, some farmers switched to no till methods in their gardens and farms to support a positive worm population. If tillage operations are absolutely necessary, farmers top their soil with organic matter like manure, green manure, and compost for their worms to consume.
Worms see the peak of their population thrive in the spring months because of the increased moisture of the season. They can lose between 20-50% of their body weight per day from excreting their mucus and castings, so they need constant moisture to thrive. To provide a consistent moisture-filled habitat for them, preparation is KEY. The cold of the winter months can exacerbate the evaporation process in the soil, especially if the fields are plowed and laid bare. The moisture in the soil will dry out quickly and the worms within the top layers will freeze easily, eventually leading them to die off (good thing they are quick to reproduce). In the winter time, make sure to prepare cover crops to retain the moisture in the soil. That way the eggs and young worms most vulnerable to the elements will be safe to thrive in the spring!
Finally, reduce fertilizer and agricultural chemical use if possible. Low levels of pesticide use are enough of a detriment to our squirmy friends. If a pesticide does not prove to be lethal, they can cause damage in other ways, especially affecting their reproductive functions. For example, the neonicotinoid pesticide imidacloprid, known for its toxicity to honey bees, also damages worm populations by damaging their DNA and their ability to produce cocoons and sperm. Reducing the use of these chemicals will directly benefit the worm population and their offsprings.
Caring for worms also means caring for the soil through reduced tillage operations, increased cover cropping, and reduced agricultural chemical use. In the end, a more sustainable garden or farm will be created and the soil’s worm population will flourish. It’s a win-win situation! Remember our unseen friends beneath the soil the next time you go out to the garden. Happy planting! :)