Strange stories

Honorary salvation for a soil pest

Why you should put a memorial to the earthworm

(Published in GralsWelt 78/2013)

It is surprising, almost dismaying, to learn how ignorant many people were in the 19th century. For example, how little did farmers know about their arable land and its life in the soil, on whose fertility the crop yields and thus the well-being of many people depend.

We are not talking about the microorganisms in the crust of the earth that can only be seen with a microscope, but about a "little bristle" that occurs almost everywhere, the earthworm that everyone knows. This was decried as a pest among the farmers - until a naturalist finally recognized its usefulness.

vacation on the farm

At the end of the 1830s, a young biologist was recovering on his uncle's estate after a long trip around the world. He showed his nephew that objects lying on the surface of the earth slowly disappear into the ground ...

The earthworms are to blame. They eat organic material (crop residues, leaves, etc.) and carry their excretions - new humus - to the surface of the earth. In doing so, they gradually undermine everything that lies on the surface and inadvertently also help the archaeologists. These could hardly dig up objects lost centuries ago - coins, jewelry, weapons, etc. - today if earthworms had not taken care of their “burial”.

Earthworms can be found almost everywhere where the ground does not freeze over continuously or is too dry; in the Alps up to 3,000 m altitude. There are around 3,000 species worldwide, around 40 in our latitudes. The useful worms have many enemies: hedgehogs, moles, shrews, birds, etc.

The uncle's observations fascinated the nephew. He built experimental set-ups, some of which developed into long-term studies, and paid close attention to the inconspicuous soil dweller for almost his entire life.

It was not until more than four decades later, on October 10, 1881, that a book appeared as the result of his studies with the title: “The formation of the soil through the action of worms " (1).  

Have you guessed the author yet? He was called Charles Darwin (1809-1882)!

With his writing, Darwin refuted old prejudices and declared the earthworm, as a humus manufacturer, to be one of the farmer's most important friends and helpers: “Worms prepare the soil in an excellent way for the growth of fibrous plants and for seedlings of all kinds. They periodically expose the soil to the air and sift it through so that no stones that are larger than the particles that they can swallow are left in it. They mix the whole thing intimately, like a gardener who prepares fine soil for his most selected plants. " (1, p. 175).

And earthworms are not only helpers of the farmer, but also of the archaeologist: “The archaeologists should be grateful to the earthworms, because for a very indefinite period of time they protect and preserve any non-decomposing object that has fallen on the surface by burying it under their excrement. In this way many elegant and curious paneled pavements and other ancient remains have been preserved, although in these cases the earthworms were undoubtedly aided by the washing or blowing of earth from the neighboring country […]. Even old, massive walls can be undermined and brought down; and in that regard no building is safe unless the foundations are six or seven feet below the surface, at a depth at which the earthworms cannot work. " (1, p. 175).

Between 10 and 400 earthworms live in one square meter of soil; the healthier the soil, the more. Their total weight can be over 3 tons per hectare. The piles of excrement excreted by the worms are tiny; but in total it results in an incredible amount. Darwin estimated 150 pounds per hectare. According to new projections, it should be considerably more: up to two and a half tons of worm solution per hectare per year!

Darwin's conclusion: "One can doubt whether there are many other animals that have played such an important role in the history of the earth as these lowly organized creatures." (1, p. 177).

But thanks to that, the earthworm still harvests very little. When plowing in the field or surrounding the garden, it is still dismembered, and not even the archaeologists put a monument to it. He is - even if Egyptologists and other archaeologists who dig for their treasures in the earthworm-free desert sand, disagree - an important helper for science.

(1) Darwin Charles, The Formation of Soil by the Action of Worms, March, Berlin 1983.
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The earthworm