© 2023 Dirty Worm Composting. All Rights Reserved.
In the world of organic gardening few products are more widely praised for their myriad benefits than worm castings. From increasing plant size and yield to improving the structure and health of soil, worm castings offer a number of proven advantages over other garden amendments, but why is this the case?
For us to get to the bottom of this question we need to look at what makes plants thrive in nature. Unlike modern agricultural systems that rely on huge amounts of chemical inputs every year to generate consistent results, unmanaged forest ecosystems are able to produce millions of tons of biomass without relying on anything beyond what is directly available in their environment, and this is possible due to the powerful process known as nutrient cycling that takes place in healthy soils all around the world. Plant roots don’t grow in a vacuum, and in fact, even just a pinch of soil from an old growth forest is likely to contain as many bacteria as there are people on the planet, not to mention a diverse array of fungi, protozoa and beneficial nematodes. All of these living organisms form a mutually beneficial relationship with plants, which offer up energy rich sugars and carbohydrates (the byproducts of photosynthesis) in exchange for a wide diversity of nutrients that only microbes are small enough and specialized enough to extract from the minerals of the soil. Bacteria and fungi, comparable to herbivores in a larger ecosystem, munch on the mineral formations of the soil, slowly concentrating their nutrients in their bodies in a form that is bioavailable to more complex life. But if that were the end of the story there wouldn’t be much in the way of free flowing nutrients in the soil ecosystem as they are largely bound up in the living cells of these organisms. Some of the most clever of these organisms have learned to exchange resources directly with plants, releasing nitrogen-rich wastes at the base of root systems and taking up plant sugars, but for the more stubborn species, their most valuable nutrients are only released into the ecosystem after they have been consumed by soil predators such as protozoa and nematodes, who only emerge when there are sufficient stocks of the “prey” species to support their numbers.
Unfortunately due to the excessive use of chemical fertilizers and pesticides in modern food production, which are toxic to all but the most resilient of microorganisms, all that remains of soil life in these systems are bacteria and in much smaller numbers than are found in unmanaged soils. As a result, while plants may still receive enough nitrogen, phosphorus and potassium to grow, so long as farmers can afford to have these shipped in from mines and factories all over the world, they now lack access to the same inputs which are available all around them but locked away in non-available forms.
This is where worm castings fit into the equation. For areas that have been stripped of their natural soil ecosystems, while it is a good starting point to add plenty of new organic material to the system by introducing compost and mulch, and this is a great way to up your concentration of existing soil bacteria, worm castings are by far the most biodiverse amendment you can introduce to your soils, containing anywhere from 10 to 100 times the number of bacterial and fungal species found in the same amount of compost as well as a plethora of soil predators such as protozoa and nematodes that immediately get to work cycling nutrients from those bacteria and fungi and making them directly available to your plants. And what’s even better, there is a naturally balanced concentration of these organisms that regulates the nutrient cycling process and guarantees that you will continue to have a rich diversity of organisms in your soil ecosystem season after season.
Like humans, every worm has a diverse gut microbiome that remains consistent throughout its lifetime, but unlike us, their microbiome is loaded with all the microorganisms soil needs to thrive, including the elusive predator species lacking in so many other organic amendments.