Earthworms are considered key soil health indicator species and an important part of the soil biodiversity family. They can have huge positive impacts on soil function, soil health and soil fertility.
Earthworms, depending on which species, burrow at different depths through the soil profile and therefore help to construct extensive systems of tunnels which help to aerate the soil and improve soil drainage.
This can help with water infiltration which can be a challenge on a range of Irish farm fields. This has given them the nickname of Natures Natural Tillers.
As well as plant litter, earthworms also ingest a large quantity of soil, this then becomes excreted as what we call ‘Earthworm casts’. These casts are high in polysaccharides, which is a source of microbe rich food and also acts a carbon rich liquid to help to form the casts into granular structures.
These earthworm casts help to improve soil aggregate formation and also due to the increased nutrient content of the casts, also help with nutrient availability to growing plants, due to increased nutrient bioavailability.
Compared to the bulk soil they ingest the casts are significantly higher in bacteria, organic matter and available plant nutrients.
With the current emphasis on the reduction of Nitrogen fertilisers on farm, increasing earthworm activity can help to provide a renewable, sustainable, organic form of Nitrogen for Irish farmers.
Earthworms can also increase Nitrogen mineralisation, through the direct and indirect effects on the soil microbial community.
Earthworms also have an effect on the Carbon cycling processes in the soil. This can sometimes depend on the different management practices on farm.
It is important to try to be kind to these Natural Tillers, which can do a lot of beneficial work for farmers, so aim to provide them with a food source and protect them from the elements e.g. chopping straw, use of composts, use of high carbon sources of manures, cover crops.
The best way to check on earthworm activity on your farm is to grab a spade, dig a few holes in your fields and have a good Pooch, see what your own soils are telling you.
If you want to know more, call us at 087 648 7899 / 087 1306661 for a consultation, or we can put you in touch with one of our partner Merchant Agronomist or Advisors in your local area.