Owen Littlejohns
July 2021
Cover cropping… What is it?
Cover cropping is an increasingly common practice amongst vine growers. Of course it’s definitely not a new practise but it’s one that is coming back in fashion and we’re pretty happy about that!
Cover cropping is a management tool that involves sowing a crop in the ‘midrow’ (The grassy bit between the vine rows). Sowing is typically done shortly after harvest to catch a bit of warmth as we move into Autumn; that way germination happens while there is less machinery activity and we can avoid driving over the seeded rows. Typically the crop is grown through Winter and then is slashed, mulched or crimped depending on the desired outcome and original purpose for the crop in Spring.
Reason ONE: Green manure
What the hell is ‘green manure’ and does it come from a cow?
Well firstly I can certainly tell you it’s not from a cow, But I bet a cow would have a field day if it found some!
Green manure is simply a temporary crop that is grown to then be cut or mulched back into the soil once it is mature, hence the term ‘green manure’. Typically a green manure seed blend will be made up of fast-growing and leafy plants that will help add nutrients back to the soil. A green manure seed blend often contains legume species such as broad beans and parafield peas. Legumes are fantastic, not only do they tend to be vigorous growers, they also go one further and fix nitrogen right back into the soil. That’s definitely a win-win by any growers standards!
Reason TWO: Soil Structure
“How’s your soil structure?” It’s possibly the sexiest question you can ask a farmer. Try it next time you meet one, you probably won’t get another word in for the next half hour.
Soil degradation and erosion can happen in any vineyard when you’re not careful. Fortunately, cover cropping gives us one more tool to mitigate it. Choosing a cover crop to help maintain ground cover such as clover or a species with a highly fibrous and dense root system like ryegrass can go a long way to maintaining the structure of the topsoil and eliminating erosion.
Reason THREE: Improving Sward Diversity
Sward?
Sward? Don’t worry, I had to look it up too. It just refers to short grass, like you’d see any paddock or vineyard. Why is it important though? One big reason at least from my experience is that it will help suppress unwanted weeds. By sowing a specific and diverse cover crop, you have a high chance of smothering out unwanted weeds; like our broadleaf enemies Marshmallow (No, not the white spongy ones you toast) and Cape weed.
Reason FOUR: Beneficial Insects
This is the number one reason I LOVE cover crops!
There’s nothing better than having nature do your job for you. When it comes to pests in the vineyard it feels like there are countless threats. Fortunately, there are also loads of beneficial insects ready to fight these threats for you. Nothing makes the beneficial insects happier and harder workers than having a diverse habitat to thrive in. Cover cropping can provide exactly that; we can use flowering species to attract pollinators to our sites and build up the habitat needed to host predators. All it takes is some forward-thinking, a healthy cover crop and a bit of management and half the battle is done for you.
That’s it, four great reasons to be excited about cover cropping!
So… Maybe next time you’re lapping up the ambience at a winery ask them about their cover cropping program. And if the response is something like “cover what?” you’ll be able to hit them with four reasons YOU love cover crops .. and why they should too!