How Worms Improve Soil

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Spreading – and pH Balancing – the Love

Soil is constantly being covered by leaf litter. Left to decompose without earthworms, it can take up to two years for leaves to decay. Earthworms can shred surface detritus in a few months. Not only does this return vital nutrients to the soil faster to be absorbed by the plants, but it gives other soil organisms like bacteria and fungi access to the food value in the organic matter. Furthermore, as the worms move through the soil, they redistribute the materials. The shredded surface litter is pulled into the soil and the deeper soil moves closer to the surface. Bacterial slime and fungal hyphae (strands) bind soil particles together, allowing the soil to retain water and nutrients. As the worms bore through the soil (they can move rocks six times their weight), they creating spaces that allow air circulation (think rot prevention) and permit water and nutrients to dissipate throughout the soil and reach the root tips. The worms also process the soil through their amazing guts, leaving behind ph neutral castings. The really cool thing is that worms correct the ph of soil with the deposit of their castings by making it more acidic or more alkaline as the need may be. According to the book Teaming with Microbes, worm castings are 50% higher in organic matter than undigested soil. Castings also have “ten times the available potash; five times the nitrogen; three times the usable magnesium; and they are one and a half times higher in calcium.” All of these nutrients are in the soil, but passing through the worm’s digestive tract “unlocks” the bonds that otherwise prevent their absorption by plant root tips.

How Worms Benefit Plants

The burrows the worms leave behind fill with castings and debris that attract roots to grow along these nutrient-rich pathways. The result is thicker, deeper, and larger root systems for plants. Burrows are also pathways for water drainage and air passage, two vital material plants need but in the proper balance. Worm burrows maintain that balance so that soil is not so soaked that the roots begin to rot nor so dry that the roots dry out. Worms also break down the cellulose and lignin that comprises plant cell walls into a form that provides food for plants. Finally, some worms sacrifice themselves for the benefit of the plants. How? Well, when a worm surfaces from beneath the soil, birds swoop in for a meal. As the bird hops around looking for the worm, its gut deposits guano rich in nutrients and microorganisms while its feet distribute beneficial protozoa. True, some worms lose their lives to the cause, but a surprising number escape!

Worms Do the Fertilizing for You

Worms produce an average of ten to fifteen tons of casting per acre per year. Just imagine having to buy, transport, and broadcast that much fertilizer yourself! But worms do it all for you, so buy some worms and give them a job.

~Louise Cooper

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