Parched soil and empty reservoirs aren't just warning signs of droughts in the summer, they’re also becoming the new normal in the early days of winter. Can science or nature help farmers endure future dry spells? We take a closer look in this edition of Down to Earth.
Vineyards at risk
Franck Renouard, a winegrower in southern France, knows a thing or two about drought. The Gard region where he is based is known for its dry Mediterranean climate. But even here, drought conditions in the winter have startled the business owner.
"We are used to water shortages in the spring and summer," he explains. "But now we’re also running low on water in the winter."
This past winter has been particularly dry. At one point, it didn't rain for over a month and half in the area. And yet the winter season plays a vital role, allowing the water table and reservoirs to replenish themselves ahead of the summer season.
It's a no-brainer, according to Renouard.
"Whichever way you look at it, the maths are simple: if you don’t fill up your bath, it won't drain. It’s that straightforward," he says.
For Renouard, irrigating his crops is not an option. The volume of water needed would be colossal: about 6 million litres in a region already suffering from acute water shortages. Drought-resistant grape varieties could provide some relief, but the winegrower offers an ominous prediction: "In the medium term, our vineyards are in danger."
The science behind future mega-droughts
In south-western France, scientists at the National Research Institute for Agriculture and the Environment (INRAE) are trying to piece together how and when droughts strike. To do so, they have designed an extreme climate simulator. It's a greenhouse, but on rails.
"Our automatic system detects the arrival of rain and then, every time it rains from May to September, the roof covers the crops and shelters them," says Marc Ghesquière, the lead researcher. "Little by little, they suffer from the lack of water."
The system is able to simulate much stronger droughts than those that occur naturally. In other words, it offers a glimpse into a future of ever more extreme climate impacts.
The goal is to understand how species behave and react in dry conditions. The next step will be to determine which genes are involved in this response and to select them for breeding purposes.
But it can take years before gene selection techniques can yield meaningful results, and crops need a helping hand now. One French start-up, Elicit Plant, is doing exactly that, having developed a product that can help plants limit their water consumption.
Its co-founder, Aymeric Molin, comes from a family of farmers who have been confronted with drought conditions throughout their lives.
"The product is made of natural plant extracts," he says. "It works by partially closing the plant's stomata, the tiny pores on the outer layer of the plant's 'skin', just like we have pores on our skin. We close them momentarily."
According to Molin, this method reduces the number of days crops are exposed to drought conditions, and yields can rise by 10 percent.
Agroforestry: A low-tech solution
Could nature itself be the best remedy against drought? Back in Franck Renouard's vineyards, an experiment is underway. The winegrower is placing his hopes on an alternative, low-tech solution: planting trees around and across his plot of land to retain the water.
It's an ancestral tradition known as agroforestry, which combines trees with crops.
Agroof, a local association, is a strong advocate of the method, helping farmers set up their own oasis of trees.
"The trees will have a significant impact on temperature levels around the vineyard," says its co-founder Fabien Lagre. "They can also affect the wind circulation, especially dry and warm winds."
In recent years, the association has seen a boom in demand for agroforestry, especially from farmers like Renouard who cannot rely on irrigation .
"We are running out of time. We will keep on planting trees in the years to come, hoping to stay afloat a little longer than the others, those who won’t have done the same."
