Have you got worms?

With winter fast approaching, it's time to reach into the back of your truck, grab your spade and start digging to look for those all-important earthworms.

The Lumbricus terrestris (as the common earthworm is scientifically known) comes in all different shapes and sizes and although small, offers significant benefits to agriculture simply due to its natural activity within the ground. The way it feeds and burrows helps to incorporate organic matter into the soil and provide better drainage, encourage topsoil formation, improve structure and enhance nutrients. Having earthworms present in your field can be a reliable indicator for the condition of your soil, as well as give an insight into the effects any current agricultural practices are having.

Because of this, digging a hole is one of the first things I do when I arrive on farm and it always surprises me how few people see this as common practice. A spade is arguably the most important tool a farmer can have in their toolbox and consistently digging throughout the season can help to identify areas of compaction and pans throughout the profile. Importantly though, it can unearth how many of those little invertebrates we really have in our soils.

What does the number of worms tell you?

Soil scientists believe the optimal number of earthworms to indicate healthy soils is 400/m². The best time to look is from now to the end of winter – particularly after rainfall (which is never too difficult given the high levels we've experienced recently!)

The quickest way to identify whether you have the recommended worm-count is to dig a 20cm³ block of soil (about the width of a spade on all 4 sides) and break it apart with your fingers into a bucket or onto a sheet. Ideally you want to find an average of 16 worms in each 20cm³ area that you dig. This can be quite an arduous task so if you are short for time, try to dig a similar sized hole and see if you can find small tunnels throughout the profile of your soil as these are evidence of earthworms being present.

If you have got lots of worms this would suggest you've created a great environment for them to thrive in and hopefully your crops will do the same.

What if there aren't any worms?

 If you find you haven't got many worms, this could be down to undesirable soil conditions (such as it being too dry, warm or acidic), heavy machinery practice or tight cropping rotations that don't favour high worm populations.

However, even where worm counts are low, making some simple changes perhaps to farm practices, rotations or soil nutrient levels could help you to create more suitable conditions for earthworms. Because they are able to establish quickly, they could be contributing to your farm's productivity in no time.

So, dig out your spade and let's find out if you've got worms! 

Ashley Huntly-Rugg
Crop production coordinator

For specific advice for your business related to this blog or any other aspect of crop production get in touch with Frontier.