We dig earthworms!
In honour of the Spring Equinox and Organic Wine Week, we’re encouraging all winegrowers to count your earthworms this week and join in celebrating these underground organic heroes on social media.
Instructions on an easy worm counting practice follow below.
Counting your earthworms is fast and fun. It is a great way to track your soil health from year to year. Healthy earthworm populations are a good indicator of healthy soil biology. In turn, organic growers know to love and respect our earthworms as these amazing little creatures provide huge support for vineyard health.
Early spring is a good time to do an annual worm count, as soil moisture conditions and temperature tend to be appropriate for earthworms to hang out near the soil surface.
This year’s Spring Equinox falls on Friday Sept 22nd in New Zealand. This day when light and darkness are equal feels like a perfect time to bring your earthworms into the light (before carefully returning them to the soil to do what they do best!).
You’re also welcome to do your worm count any day during Organic Wine Week, Sept 18-24, whenever weather and soil conditions are right in your location. Times of moderate soil moisture are best.
How to do it
1. Dig out a small hole, 20 x 20 cm square by 20cm deep.
2. Place the sod of soil on a surface (tarpaulin/cardboard/rectangular plastic bin) to count the earthworms by gently crumbling the soil.
3. When you are finished counting, record the number of earthworms, replace the earthworms in the hole and refill the hole with soil.
4. Repeat this five times in areas that are representative of the vineyard.
5. Include two samples from the undervine area for comparative purposes.
Do not sample fence lines or along driveways.
Keep a record of where you’ve sampled, the date and what your earthworm numbers are. This will enable you to track your earthworm populations from year to year. It’s also worth noting soil type and soil moisture conditions as these will influence your earthworm numbers.
We encourage you to share photos of your worms and your process on social media using the hashtag #wormcount2023. Please also use the hashtag #organicwineweek if you’re part of our organic winegrowing community.
Identifying your worms
Curious about what species of earthworms you’ve got? AgResearch has put together a helpful guide to identifying them (scroll to end of the page to find the guide). You may wish to track the numbers of the various species you find.
Why it matters
Earthworms are quiet, often unseen yet very valuable members of a vineyard team. They aerate the soil by burrowing, and their excretions are potent fertility enhancers. This means they tend to increase water infiltration and drainage, reduce compaction, benefit soil structure, and improve nutrient cycling and availability. All of these changes support better plant growth. So it’s very much worth the quick effort to check on your earthworms, and think about how you can support them to do well in your soils.
Earthworms love decaying organic matter and aerated moist soils with appropriate pH and low disturbance. The AgResearch guide also has some suggestions about how to make your soil a welcoming place for earthworms to thrive.
Shifting to an organic soil fertility programme is another great way to support your earthworms.
In addition to worm counts, early spring is a good time to do other vineyard soil assessments. With just some simple tools (starting with a good spade!) you can learn quite a lot about the health of your vineyard soils.
Doing the same measurements at this time every year can really help you track your soil health and can give your team a closer relationship to the soil beneath their feet. And there are no expensive lab tests needed.
OWNZ ran a webinar with Dr. Charles ‘Merf’ Merfield, sharing how to do a “vineyard soils WOF”: several simple hands-on soil health assessment tests. That webinar recording is online below for review.
Merf has since written up those practices in conjunction with BRI, published in a handy guide which is online here.
It’s a good time of year to remember that every great glass of wine begins in living soil.