It’s a point of pride that we farm all our own grapes at Gusbourne. It sets us apart. It’s one of the best ways to ensure our wines are as close to perfect as possible.
And, while you might instinctively think that viticulture is mainly about the fruit, in reality it goes much deeper. A huge amount of grape growing takes place under our feet.
Jon Pollard, our Chief Vineyard Manager, has nurtured Gusbourne’s vines since they were planted almost 20 years ago. He knows our sites and our soils better than anyone – and yet he’s the first to admit that there’s far more to learn about viticulture in our corner of England.
One of the projects Jon’s currently working on, as part of a Government initiative with Innovate UK, is the use of cover crops. This is hugely exciting – even if it sounds rather technical – because somewhere within the conversation about tap roots and nitrogen fixing and the microbiome is an outcome which we all care about: working with, not against, nature. Benefit, not harm.
Before we dig into this, we need a little background. Firstly, what exactly is a cover crop and why should we be interested? Jon explains: “It’s essentially a non-harvestable crop. Something we’re not going to take out the ground, grown between rows of vines.
“There are lots of potential benefits. For example, we look at how a cover crop can improve the soil structure through its rooting ability. Plants with huge, thick roots, or tap roots, can keep airways and growth channels open for the vines.
“Other crops can be used to hold on to nutrients that we add into the system. If you put down a fertiliser, not all of it will be taken up by the vines. But cover crops can scavenge and hold on to nutrients, especially over winter.” These will then be released back into the soil when the cover crop is either mown or naturally dies back. “The organic matter is fuel for the microbiome – micro flora and fauna.
“Then there’s the ability of some cover crops – legumes, peas, beans, clovers, vetches – to fix nitrogen.” Fixing nitrogen is the process where bacteria living in particular plants take nitrogen from the air, making it available for other plants – in our case, the vines. And, as any chlorophyll-fingered gardener knows, nitrogen is vital for healthy, vigorous plant growth.
Lastly, there’s the most headline-grabbing of all the reasons to introduce cover crops – the boost in biodiversity. “Many cover crops are flowering plants, which the insects love, and means we’ll be bringing in more species to the vineyards. It’s all part of this regenerative agriculture movement.”
Working with nature, protecting the soil, nurturing biodiversity, bringing livestock into the system – these are the essential ideas behind regenerative farming. The key to a sustainable future for wine.
So, the potential benefits are clear. But what’s needed next is data. Research to prove that changing the way we farm isn’t just good for the soil, the insects and the vines – but also for the wines too.
This is where the Innovate UK project comes in. Gusbourne is a couple of seasons into the study, planting different crops and looking at the best ways to manage them. We’re trialling perennials that can go through the autumn and winter – “mining and holding on to the nutrients that escaped the vines,” says Jon. These are familiar names such as clovers and fescues.
“With these crops, you let them grow through the winter to increase the biomass as much as possible. Then you mow in the spring to make sure there’s enough ventilation under the vines. The cut cover crop is going back on to the rooting area under the vines, returning all their nutrition to the soil.
“Then for spring and summer growth you get annuals. Last year we planted some Phacelia – a vigorous plant that reseeds. And we’ll be putting in some fava beans which should grow strongly in the growing season and then we’ll cut them at the end of the growing season and use them to help establish the next perennial crop.”
With spring now upon us, it will soon be time to get a new batch of seeds in the ground in Bottom Camp, one of our Kent vineyard sites. A new growing season lies ahead, and with it more data to collect.
“It’s too early to see any concrete results from the trial,” says Jon. But, even without the scientific evidence, instinctively it feels like the right direction.
“Typically, we grow the vines plus about four species of grass,” says Jon. “So if we can increase the diversity of plant life, we’re also increasing the diversity of the fungal and bacterial life in the soil. Which means you have a better chance of having a symbiotic relationship between those fungal bodies and the vine roots.
“The fungal pathways can deliver micronutrients to the vines; in return the fungi are getting food from the carbohydrates the vines pump into the soil.”
It's a virtuous circle. Or, perhaps better put, a virtuous cycle.
The InnovateUK study may well pose more questions than it answers. But there’s little doubt that, for Gusbourne, a low-intervention, nature-first way of farming is key to our sustainable future.