Earthworm Engineers #2 – Arable Farming & Earthworm Populations

5184 3456 Sectormentor for Soils

Welcome to the second in our Earthworm Engineers series where you can learn from some of the best science about the value of these amazing creatures. We’re so excited that Professor Jenni Dungait is now the editor of the European Journal of Soil Science – and she’s made some important earthworm papers open access for a short time. We’ve picked our favourite four and summarised them in this blog series.

Access the earthworm archives in the European Journal of Soil Science, to learn more about the science behind on-farm worms!

#2: Effects of different methods of cultivation and direct drilling, and disposal of straw residues, on populations of earthworms

This paper was written in 1979, and uses some pretty intense soil sampling methods (dousing the sample sites with formaldehyde to isolate worms) – we think they probably could have done with Sectormentor for Soils to count earthworm populations at each site!

The paper makes some interesting conclusions about the effects of cultivation on earthworms in topsoil. They tested the number of earthworms over four years on direct-drilled fields that were sprayed with herbicide before planting, and ploughed fields (of varying soil types). They found earthworm populations were consistently greater in the direct-drilled soils compared with ploughed soils, although deep-burrowing species were affected similarly in both treatments.

They also test the effect of spreading mulch on the fields compared to burning straw residue, and find (unsurprisingly) that earthworm populations were greater in fields where straw residue was spread rather than burned, particularly in surface feeding species. This surface debris becomes an important food source for the worms, and makes their diet more stable.

The paper also suggests that the extra earthworm channels created under no-till soils may help to reduce any compaction in the soil, as well as distributing organic matter and increasing drainage. The presence of worm channels may also allow plant roots to penetrate more deeply, which can also reduce compaction.

It’s nice to know that regenerative farming approaches have such a positive influence on the earthworm community. We’re really excited to speak at Groundswell this year on how to become a soil expert on your farm, and to learn more about the benefits of no-till systems.