Soil. Dirt. Mud. Whatever you want to call it. Turns out it’s quite exciting stuff and I’ve become more than a little bit obsessed with it recently….
Soil health is the ability of a soil to sustain crop and livestock productivity long term. Ultimately – if your soil’s healthy, your crops will be healthy. If your crops are healthy, be it grass, legumes, maize whatever, it will all help towards maintaining a healthy, productive herd/flock. Which means I’m a happy vet!
How do you know if your soil’s healthy?
Well, you can probably tell me more than I can tell you and please do! There are tests which you perform annually, chemical and physical tests, soil pits, lab tests, etc but there are also biological tests. These look at the amount of “macrofauna” – big bugs like worms, spiders and beetles or your soil’s “structural engineers”.
The number of earthworms in a field is a good indicator of soil health. High numbers can bring many benefits.
Earthworms need oxygen to live and therefore, compacted, deoxygenated and poor quality soil do not contain as many, if no earthworms. Worms have been proven to enhance soil structure, improve drainage and break down organic matter and turn it into plant nutrients.
Vermicast or worm poop applied to soil produces higher plant yields. It has also been shown to reduce plant disease, your very own feritliser/pesticide – for free!
I asked a local farmer if I could dig some holes in his field to do some worm counts. He laughed and stated that “it wouldn’t be the weirdest thing you’ve done!” Brilliant. He was on board!
So, on a quiet Saturday afternoon armed with a spade, a bowl, an ID chart, helpfully downloaded from AHDB, the dog and the wind of Storm Ciara, I headed out to a field of permanent pasture. To the naked eye, this field looks like many others, the odd bird flitting about and rabbits darting away into the woods. Fairly ‘quiet’ on the nature front…. Or that’s what I thought until I started digging!
I dug several holes (before the wind got too much and I’d chased my plastic ‘worm bowl’ across the field for the third time). AHDB reckon 7-10 across a field is ideal and what I found really surprised me – loads and loads of worms.
Earthworm Types
In a 20x20x20cm patch I found over 40 worms (16+ is considered good)! These worms included several species and most importantly three different ecological types. All of which bring different environmental and soil structure benefits. A whole army, working for you – right under your feet!
Litter-dwelling or epigeic worms are exactly that, they don’t actually live in the soil, but just above. Matchstick sized – they are great prey for native birds. They feed on decomposing organic material such as grass and manure playing an important role in carbon cycling.
Topsoil earthworms are a little bigger and are the most common type found in your fields. They have horizontal burrows and are important for soil health, aggregation and nutrient cycling for plants.
The anecic earthworms are around 8cm long and are the typical ‘big lads’ of the earthworm community. They dig deep, vertical burrows that massively improve soil aeration, water infiltration and root development.
All of these guys are sensitive to tillage, waterlogging, compaction and soil pH. So if they’re there at all, it’s usually good news!
I’m looking to do more of these counts on different cropping systems and grasslands/meadows if anybody is interested in finding out a bit more about what’s happening in their soils so please let me know if you’re interested. I might even do a soil structure assessment at the same time if you’re lucky!! Hopefully, with the weather picking up, we’ll all get out to enjoy the sunshine how we want to, worm geek or not!
Claire
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