Earthworms: What are they? How to breed them? How are they used?

the earth wormsthey play an important role in the composition of the soil and in the recycling of organic waste.

They are part of a network of organisms thatconvert organic waste into a nutrient-rich substratefor crops and all kinds of plants. In addition, they increase the porosity of the soil and make it easier for the water to be absorbed by the roots, contributing to the photosynthesis process, which is so important for living beings.

However, not all earthworms are beneficial. Some can be very harmful pests for the plants in our garden. They are larvae of other insects that feed on the roots and other parts of the plant and prevent its proper development.

Let’s see those varieties that will be useful to us to increase the fertility of our soils.

What are earthworms like?

Among the beneficial species we find earthworms. There are more than 7,000 species of earthworms, divided into 23 families and more than 700 genera.

They are classified into three large categories from an ecological point of view:

a) Epigea:They live in the superficial layers of the soil and feed on the remains of decomposing organic matter. Its reproduction is accelerated and numerous.

They are the worms that are usually found in gardens and the most cultivated to fertilize the soil. These worms dig vertical galleries up to two meters deep, depositing their droppings at the entrances.

b) Endogeal:They are found permanently inside the soil, feeding on the soil more or less mixed with organic matter.

They come to represent between 20 and 50% of the biomass of European fertile soils.

c) Anecic:They live deep in the earth, very close to the roots of plants.

They dig deep vertical galleries, where they drag organic remains that they use as food once they have been mixed with the soil.

They are very difficult to find, as they do not venture to the surface.

Additionally, earthworms have been used to encourage biodynamic agriculture.

Types of Earthworms

Among the most beneficial earthworms we find the following varieties:

Eisenia foetida

Popularly known as the Californian Red Worm, and although it actually comes from Europe, it is called that because it was in California where it began to be used as an organic alternative for fertilization. It is also called the Eurasian tiger worm.

They are raised in places that do not exceed 40ºC, their ideal temperature being between 14 and 27ºC. They are dark red or brown with yellow stripes (like tigers), and are between 6 and 8 cm long. They do not support sunlight and live between 3 and 5 years.

This variety is the most used for organic crops. The Californian earthworm excavates the ground as it eats, depositing its droppings in different layers of the earth, making the ground more fertile.Ideal for making earthworm humus.

Eudrilus eugeniae

Known as African Earthworm or Night Crawler. It is a species native to West Africa, widespread in warm and tropical regions.

Its ideal development temperature is between 25 and 30 ºC. Under ideal conditions, it reproduces more rapidly than the California red worm. They are grey, with shades of purple, with sharp posterior segments.

Dendrobaena veneta or Esisenia hortensis

Despite having two different scientific nomenclatures, it is the same species of earthworm.

The use of one or the other depends on the region in which you are. She is popularly known as Dendra or Nightcrawler. It is a pink or gray worm, with segmented bands that give it a striped appearance.

It is found in European forests and, although its use is more common in fishing, it is increasingly used as a composting worm.

Its ideal development temperature is between 18 and 25 ºC. Compared to the Californian red worm, this species is better adapted to an environment with a high carbon to nitrogen ratio, making it an excellent choice for composts that are high in fibrous or brown materials.

As a disadvantage, it can become a pest if care is not taken in its cultivation.

Perionyx excavatus

It is an Asian species, small in size, also known as blues or Indian blues. It is believed to come from the Himalayan region. They are dark colored worms, almost black. Very long and thin.

They are suitable for vermicomposting in tropical and subtropical regions and are increasingly being used throughout North America.

Lumbricus rubellus and Lumbricus terrestris

Known as blood worm and common worm, respectively. They are species native to Europe, and develop at temperatures between 18 and 23 °C.

They live in soils with a lot of organic matter and prefer those with manure. They require soft and very moist soils to be able to make their holes.

Its presence increases the concentration of vitamin B12 in the soil.

eisenia andrei

Or common red worm. It is a relative of the Californian red worm and, like the latter, can carry out its activities in the surface layers of the earth.

They prefer compost and soils with plant debris, such as leaves, and are not very inclined to live on soils with high mineral content.

They are distinguished from the California roundworm because they are darker and their stripes are less pronounced.

How are earthworms born?

Earthworms are hermaphrodites, which means they have both male and female sexes. This allows a specimen to fertilize and be fertilized at the same time. What they cannot do is impregnate themselves.

The fertilization process lasts about three hours. The worms are placed in opposite directions, that is, one places the “tip of its tail” on the “head” of the other. Both remain attached by a viscous substance that releases the clitellum, one of the rings of the worms.

Once they have attached, they begin to inject sperm into each other. Sperm cells are stored in an organ called the spermatheca. When they have finished exchanging sperm, they finally separate.

Subsequently, the clitellum again secretes a viscous substance, this time to form a crust to protect and feed the eggs, somewhat akin to a butterfly cocoon. As this substance is secreted, the worm begins to crawl backwards.

This movement has two purposes: the first is to move the viscous substance from the clitellum towards the head. The second consists of collecting the ovules to take them to the spermathecae where they will be fertilized.

Thus, the worm continues to crawl backwards, and when the ovules have finally been fertilized and covered by the viscous substance, the cocoon is formed. The cocoon finally detaches from the body of the earthworm and is left on the ground, without parental supervision.

A single cocoon can contain between 3 and 20 specimens, which develop over a period that varies between two weeks and three months, depending on the species. When the young have developed, they break out of the cocoon and begin to feed.

This process can be carried out several times, during the average 4 years that each individual lives.

What do earthworms eat?

the earth wormsThey feed on organic matter found in the soil.. In doing so, they help dilute and break down certain minerals and other compounds, which are returned to the soil in the form of excrement.

This is because earthworms harbor certain species of microbes in their digestive systems that help break down nutrients better and make them easier for the soil to absorb.

Thus, as they move forward, the worms deposit their droppings throughout all the layers of the earth, effectively dispersing nutrients.

This is why crops containing earthworms are richer in nutrients and more spongy, which facilitates aeration and water retention.

On average,worm droppings contain:

• 5 times more nitrogen.
• 7 times more phosphorus.
• 5 times more potassium.
• 2 times more calcium.

Why are earthworms important?

Among the main benefits they bring to the substrates we find:

• Improves aeration and water and nutrient retention capacity.
• Improves the germination capacity of seeds.
• Reduces soil erosion.
• Improves soil management.
• It enriches the substrate with organic substances and essential minerals.
• Promotes the assimilation of nutrients by transforming them into assimilable forms.
• Preserves and raises the organic content of soils.
• It favors the formation of mycorrhizae.
• Increases beneficial microbial flora.
• Increases plant resistance to pests and diseases.
• Does not contain bad odours.
• Improves the flavor of the fruits.
• Protects crops and makes them more resistant.
• It is suitable for all types of crops.
• Its excessive use is not harmful.

How do we take care of them?

Usually,earthworms do not require much care. Of course, we must ensure that we do not give them direct sunlight, since, being animals that live underground, they do not tolerate sunlight and can die within a few minutes.

Place the worms in a tray big enough and deep enough to fit all of them, but not to spill out. Cover it with soil and keep it in a dark and temperate place, in ideal climatic conditions, depending on the species you want to breed.

Feed them once a week with organic material such as leaves, grass, manure, kitchen scraps, compost, etc. Place this material on the ground. The worms crawl up to the food and go back down to their burrows when they are done eating.

Aboutyou must provide each month, half a kilo of foodfor every 30 cubic centimeters of space.

Thus, if you feed them every week, divide the amount of food into four parts, each one will correspond to the amount of weekly food.

Moisten the soil with each feeding, but be careful not to form puddles, as earthworms can drown in standing water. If you prefer, cover the bathtub to keep moisture inside.

Finally, if the soil is very acidic, every two months add lime and a little wood to keep the pH level between 6.8 and 7.2.

Where can we get them?

The most recommended is to buy them in fishing or agriculture stores. If you prefer, you can also buy liquid worm castings in specialized stores.