Why do we love earthworms, exactly?

Seeing earthworms around in your garden means you are having billions of contributors to healthy soil. They are bacteria, fungi, protozoa and nematodes. Together, they form the soil food webs. 

Humus is food for earthworms. Earthworms swallow humus and release ammonium
Seeing Earthworms in the garden means there are healthy food webs in the soil

What the hell do these germs, bugs and worms do to your soil?


Do you know that plant root constantly release exudates with sugar, protein and shredded root tips attract to bacteria and fungi, boosting microbe community in the soil? It's amazing that I studied seven yrs in agricultural major, I still didn't know that. 

Plants roots exude sugar, protein, acid and root tips, these are food for bacteria to decompose. The slime that bacteria produce to attach themselves on soil particles will also make soil aggregates which help store water and air
Plant root exudate foster bacteria in the soil

Bacteria produce "slime" to stick themselves on the soil particle otherwise they will get washed away.  Just think about the "plaque" forms overnight on the teeth. Hard to remove, right? You even need a brush.

The "slime" is a tough glue, together with the pressure of plants root growth, will make soil crumb structure. Within the soil crumbs, there are more spaces to store air and water.


There are pores between soil aggregates or crumb structure. These pores store water and air
Soil crumbs create more spaces holding more water and air in the soil


Bacteria act as "storage bag" of nitrogen in the soil. Bacteria are made of nitrogen. When they are alive in the soil, they keep the nitrogen in their cells. When bacteria die or are eaten by their predator, protozoa, the nitrogen will be released as digestive wastes to the soil and available to the plants, usually in ammonium form(NH₄⁺). 


Who are they?
Paramecium, Amoeba, Euglena, Ciliates and Flagellates.  

Protozoa are the cute little things who have only one cell and only can be seen under microscope. They eat bacteria and fungi. When they ingest bacteria, the waste they produced contains carbon and nitrogen available to the plants. Do you know that in nature,  80% of the nitrogen a plant needs comes from the wastes produced by bacteria-and fungi-eating protozoa? 

Protozoa mineralize the soil nitrogen and make it available to the plants. 


Nematodes are non-segmented, blind roundworms that, along with protozoa, mineralize nutrients contained in bacteria and fungi.  Over 20,000 species have been identified so far. Some of them eat protozoa. Some eat bacteria and fungi. Some eat living-plants, or even grub and wasp. Some eat organic matters in the soil. 

Nematodes again are big mineralizer in the soil. They ingest bacteria, fungi, protozoa and organic matter, and then release the nitrogen once immobilized in these microbe, usually in ammonium (NH₄⁺) form.


Mites, springtails, termites and ants. 

Arthropods are shredders and aerators. They chew up organic matters in the soil , making them small pieces. Then, fungi and bacteria can use enzyme to decompose the small pieces. 

Arthropod transport bacteria from side to side, help them spread all over.  Remember why we shouldn't touch cockroaches? Because bacteria attach to the surface of arthropods. 

With healthy Soil food, soil can restore itself and rich in nitrogen. Nutrients fully cycle in the soil.
Bacteria, Fungi, Protozoa, Nematodes Arthropod mammals and bird together  form soil food web


Earthworms eat primary bacteria, along with protozoa, nematodes as well as organic matters. Earthworms swallow the organic matters, grinding them in their digestive trails. Finally, it's the bacteria living in this trail can digest and produce nutrients for earthworms. Earthworms absorb the nutrients. Any organic matter that is not fully digested is pushed out as waste (worm casting). It is precious soil amendment for organic gardeners.  

When earthworm move in the soil in search of food, they create more pores, channels and transport bacteria and leave their castings from side to side.  

All these contributors work for your garden soil. They improve water holding capacity, aeration, drainage. They work like a system. Bacteria keep nutrients the soil and protozoa mineralize them, being available to plants. Earthworm is the omnipotent one. She swallow everything in the soil and leave castings full of nutrients for plants. 

Use compost and organic mulch to feed them , instead of commercial fertilizer and herbicide to kill them. You will have these soil food webs working for you.