Micro-Cosmic: The Hidden Universe Beneath Our Feet

For years, the Research and Development team at Domaines Barons de Rothschild Lafite has been fascinated by the tiny life-forms that nourish our grapevines: microorganisms. Concealed underground and invisible to the naked eye, these minuscule powerhouses are hard at work digesting and enriching the soil that feeds the vine roots. Dive beneath the surface, into the microbiome of our vineyards.

Shovels in hand, hats perched atop our heads, we are digging around Aussière’s vineyards. As spring comes to a close, we are planting… underwear. Organic cotton briefs are buried about a foot deep, where they will remain until summer’s end. Four months later, not a single pair comes out intact – depending on where they were planted, some are close to unrecognizable: the cotton has been completely digested.

Beneath the surface of the soil, tiny beings are now well-fed: our microorganisms. They range from bacteria and fungi to algae; these microscopic creatures and microbes play a central role in soil fertilization. If the Government of Ontario’s website is to be believed, «there are more organisms in a teaspoon of healthy soil than there are people on Earth».

«The vine doesn’t feed itself; it’s mostly the fungi that do the feeding» explains Manuela Brando, R&D Director at Domaines Barons de Rothschild Lafite. While science hasn’t definitively connected a well-fed vine to a more productive one, she’s sure that the two are linked. «For example, when we’re healthy and not tired, we perform better. So I believe that a healthy, well-nourished vine will produce better wine».

This is the third straight year the ‘underwear test’ has been run in France at Domaine d’Aussières, Château L’Evangile and Rieussec, as well as in Argentina and Chile at Bodegas CARO and Viña Los Vascos. It’s a cost-effective, nature-friendly, and eye-opening way to gauge the soil’s microbiological activity. The underwear’s degree of decomposition varies depending on its location; once unearthed, it’s weighed to assess what’s been lost to decay.

Our first finding? Water is the biggest game-changer for microorganisms. Without it, no decomposition happens. Trees also seem to promote proliferation. Another key factor is the soil’s fertilization level, particularly the richness of its compost.

The dung beetle: a compost virtuoso

Horn pointing skyward, front legs dug into the earth, a tiny dung beetle is rolling, with its back legs, a ball of manure three times its stature. Don’t be fooled by its small size: the dung beetle is the world’s strongest insect, capable of lifting up to 1,141 times its own weight.

While modern society might overlook the dung beetle, it hasn’t always been so. In Ancient Egypt, countless frescoes and engravings celebrated the ‘sacred scarab’, another name for the dung beetle. Its astonishing physical strength only equals its ecological impact: this insect plays a central role in the ecosystem. So much so that in the 1960s, the Australian government imported around 40 species of dung beetles to enrich their soil, in an operation called the ‘Dung Beetle Project‘.

According to the latest SEPANSO report, which focuses on beetles in the Lafite Marshlands, the area «now holds the largest variety of dung beetles in the Gironde region». The NGO has identified 31 species of dung beetles between 2012 and 2022, some of which are new and exceptional for the region. «This doesn’t surprise me,» says Manuela Brando, with a smile. «But I’m thrilled about it».

Unlike the Australian effort, dung beetles found their home naturally on the lands of Château Lafite Rothschild — thanks to their love of cows. In the vibrant biodiversity of Lafite’s marshlands, about thirty Marine cows roam freely. This endangered breed was introduced by Baron Eric de Rothschild.

Manuela, who has been working here for a decade, has always seen them wandering through the marshes. «I think Baron Eric had a ‘naturalistic’ approach,» says Manuela. «He wanted to protect an endangered cow species. He did it out of passion, out of a calling—he simply loves these marshlands». And in fact, besides being protected, the Marine cows contribute to soil fertilization with their dung – a fact which the beetles relish.

«The dung beetle is the perfect example of an auxiliary insect,» Manuela continues. An auxiliary insect, she explains, helps us humans to take care of the land. «They balance the ecosystem. They bring microorganisms » she adds.

«This compost, these microorganisms, are the stomach, the digestion, the nutrition. They’re also what allows the vineyard to thrive».

The head, the heart and the ‘gut’ of our estates

On our estates, dung beetles aren’t the only ones enriching the soil with manure—we humans have also gotten our hands dirty. Since 2017, we’ve been conducting experiments on 15 hectares of our land: we collect cow dung, pack it in cow horns and bury it. «This produces a small amount of manure that we can spread over our plots,» explains Manuela. «The preparation then acts like a starter culture of microorganisms; we inoculate our parcels with this culture».

‘Cow-horn manure‘ is a core practice in biodynamic agriculture. In biodynamics, the farm is seen as a living organism, a holistic entity. In this approach, the health of the soil and ecosystems is paramount, and we are here to take care of it.

Though it promotes a nature-friendly culture, biodynamics is also a controversial practice, often criticized for its esoteric dimension. For this reason, in addition to her role as the Head of R&D at Domaines Barons de Rothschild Lafite, Manuela Brando is conducting a thesis on the «effects of biodynamic preparations on vine functioning and grape composition». Through her research, Manuela aims to understand whether there are scientific foundations to the effects of biodynamics.

«It might be a quirk of the profession, but in biodynamics, we talk a lot about the ‘body‘» continues the researcher. Silica, a mineral derived from crushed quartz found in sand, clay, or even cow horns, is considered the ‘brain‘ of this ecosystem. Nettle, rich in nitrogen, is its ‘heart‘. And manure is the ‘gut,‘ responsible for digestion. This blend of silica, nettle, and manure forms a complete meal for microorganisms.

«Today, we conduct extensive studies on the vine’s microbiota,» Manuela goes on. The ‘microbiota’ refers to the community of microorganisms living in a body or a substance. Indeed, current scientific studies have shown that 99% of the human genes expressed within us are not in our DNA, but in that of our microbiota. When it comes to the vine, it could be very similar.

«We humans are holobionts,» Manuela Brando resumes. But what exactly is a holobiont? It’s an organism composed of both its genetic tissue, as well as that of microorganisms. «These two tissues co-exist, function in synergy. They cannot live without each other, that’s what creates the concept of a holobiont». Indeed, she elaborates, «we’ve realized that the vine is also a holobiont, like all other plants». As a result, the study of the vine’s microbiota «is the study of all its microorganisms: at the root level, in its leaves, and its fruit –  all of which function in synergy with the vine’s physical body, allowing it to live, interact, and operate.”

«We used to overlook all these microorganisms,» observes Château Lafite Rothschild’s R&D Director. «We’re now starting to realize that we have a lot to learn from them». In her view, the study of the microscopic, of the microorganisms, is «the science of tomorrow».

The research, her thesis, the buried underwear… to Manuela Brando, all these elements are intertwined. «These are things we do to assess the life of our soil, the presence of insects, of plants that can help us enrich the overall biodiversity of our vineyards». And when asked why Château Lafite Rothschild is leading these projects, she pauses for a second and says, «If vineyards like ours aren’t conducting this research, then who? I believe that it’s pretty much our duty».