Reviewed by Julie Rawson
I am on an earthworm self-education binge right now, and when I start on such a binge I often find it helpful to go back into history a bit. For example, I am halfway through both of Weston A. Price’s Nutrition and Physical Degeneration and William Albrecht’s Foundation Concepts as I write this. Reading these authors who wrote from 70 – 100 years ago gives me an important perspective regarding our present day concerns about topics like climate change and carbon sequestration. I didn’t know until recently that Charles Darwin was a major force in our understanding of the earthworm and its role in agriculture and humus management. He spent 39 years studying the earthworm before he published The Formation of Vegetable Mould, Through the Action of Worms, with Observations on their Habitats in 1881, right before his death.
Thomas Barrett was born in 1884. He was a real Darwin fan, quoting the great scientist as saying, “It may be doubted whether there are many other animals which have played so important a part in the history of the world as have these lowly organized creatures.” And Barrett was a real earthworm fan, too. His book is divided into 2 parts – The Earthworm and Its Environment, and The Earthworm Under Control.
I found the first section of the book, The Earthworm and Its Environment, the most attractive and educational. Chapter one is on humus. “Humus is the end product of plant and animal life and must be created for current use from day to day and season to season,” according to Barrett. He speaks poetically of the single-celled yeast plant all the way to the giant sequoia eventually finding their way to the common burial place – the compost heap of nature. Barrett notes that the creation of humus from dead animal and vegetable matter usually takes from weeks to years with the notable exception that earthworms excrete humus. “Earthworms are the shock-troops of nature for the quick production of humus while she is waiting upon her slower processes,” says he.
Aristotle called earthworms the “intestines of the earth”. W L Powers, a Soil Scientist from Oregon State labeled them “colloid mills”. They produce the intimate chemical and mechanical homogenized mixture of fine organic and inorganic matter which forms their castings. In the alimentary canal the ingested materials undergo chemical changes, deodorization and neutralization, such that the resultant castings (manure) are a practically neutral humus, rich in water soluble plant food, and immediately available for plant nutrition.
According to Barrett, the earthworm is one of the strongest animals in nature for its size. Its body is formed by a series of from 200 to 400 muscular rings. “Thus everything that opposes itself to the blind attention of the earthworm becomes something to be devoured,” says Barrett. Here is how it works. The earthworm pushes itself through the soil, ingesting as it moves. All ingested material passes into the crop and then into the gizzard as a semi-liquid plastic mass. The grindstones of the gizzard, along with digestive juices similar to those found in human beings, act on the contents. A remarkable feature of the earthworm’s anatomy is the calciferous glands, located in the walls of the esophagus. They are unique to the earthworm. The liquid calcium that they secrete exerts its neutralizing action on the acids of the material that passes through the worm’s alimentary canal. Continuing with the digestive process, the material takes on valuable added elements from the intestines and urinary excretions. The end product is manure or castings.
Barrett enumerates the many values that worms provide to agriculture. Briefly, he mentions that they go deep into the subsoil and bring the minerals that are present there into the surface layers, and they greatly increase the air capacity of the soil and its water holding capacity. When their numbers are significant, they normalize pH, and increase calcium carbonate and nitrogen in the soil. The colloid humus content increases and the microbial life increases, and the nutrients in the soil are more highly water soluble and plant available. Finally, as a by-product of their castings production, resistance to pests and disease is enhanced in soils that are actively inhabited by earthworms. Barrett reminds us that the number of earthworms in a given environment is limited only by the amount of available food.
One of the most memorable parts of the book, for me, was the telling of a story by a friend of his about the friend’s grandfather’s farm in Ohio between the years of 1830 to 1890. This 160 acre farm boasted several paddocks that rotated between grain production, and pasture for mixed livestock. The barnyard, which opened into the paddocks, held oat and wheat straw stacks on raised covered platforms, for the livestock to eat during the winter and use as bedding. In the center of the barnyard was a compost pit that was fifty feet wide, 100 feet long and 2 feet deep. There were cables running between the barn and the pit attached to 12-15’ tall posts. Dump buckets from the barn were shuttled out to be dumped into the pit every day. From a spring nearby a flume was constructed to be used for adding water to the compost pit as needed. Chickens and ducks worked the pile throughout. At intervals, the farmer would add red clay in layers to the pile. When spring arrived, the compost (minus a starter of worms and compost for the next batch) was hauled away to the fields, and the compost and worms were ploughed into the field. The grandson’s job at this time was to shoot as many crows as he possibly could, because they came in the hundreds to devour as many worms as possible before they were ploughed into the soil! This farmer was renowned far and wide for his high quality crops, seed, livestock and ever more fertile soil.
The second half of the book talks about vermi-composting in more controlled settings like boxes in basements and/or shady outdoor locations (the author was from California). I found this section of the book not as intriguing, as a lot of the materials used in the process are not readily available now for possible replication. And, being a somewhat lazy farmer, my main interest in increasing worm populations on our farm is through appropriately worm-attractive practices in the field.
This book is short at 160 pages, and is an easy read. Some of the history in it is quite interesting, and Barrett’s ultimate enthusiasm for earthworms and their value is quite infectious. I leave you with the following quote: “We have written a book in an endeavor to create a mental picture of the most important animal in the world – the earthworm. When the question is asked, Can I build topsoil? The answer is ‘yes’. And when the first question is followed by a second question, ‘How can I do it?” the answer is ‘Feed the earthworms.’”