Between the vines, a black sheath threads its way. Jean-Claude Maillol points to the rows that line up in front of him, and details the different grape varieties with a machine gun flow: “Here it’s Syrah, there Grenache, and Carignan a little further .” A few kilometers from the center of Montpellier (Hérault), the air of this mid-July is hot, the heat wave is not far away, and the former agronomist does not lack excitement to recount the irrigation experience that is played at his feet: “We try several techniques, a buried drip, another directly on the vines… All this is controlled and analyzed by devices.” If the system may seem banal, the resource used to supply these plantations is less so: it comes from the dirty water of Murviel-lès-Montpellier, a small town of 2,000 inhabitants nearby.
Faced with a historic drought, France is thirsty. More than 90 departments out of 96 are subject to restrictions, and some villages even lack drinking water. Throughout the territory, farmers and scientists are trying to find the answer to these ever-increasing tensions over the resource. “Here we are studying how wastewater can be used for agriculture”, explains Nassim Ait-Mouheb, researcher at the National Research Institute for Agriculture, Food and the Environment (Inrae) who has not far from a dedicated laboratory installed in the treatment plant. By analyzing the residues of pollutants, but also of nitrogen, on different crops, the researcher is trying to find the right balance in the treatments to make reuse a solution to the problems of drought which are increasingly imposed on farmers. In Murviel-lès-Montpellier, irrigation using wastewater is still at the experimental stage. But, in this very wine-growing region, climate change and the modification of practices could make REUT (reuse of treated wastewater) very attractive for local winegrowers.
Maintain consumption standards
“The vine is rather adapted to drought and does not traditionally require water, so irrigation is there to maintain the level of production, and to compensate for rainy episodes, which are no longer the norm”, explains Nassim Ait-Mouheb. . Above all, the use of watering could become essential to continue to produce a wine that meets current consumption standards. “The public is fond of wines that are lighter and lighter, but the rise in temperatures generates wines with a higher alcohol content. So, with three or four irrigations, you can significantly lower this rate”, assures Jean-Claude Maillol
Jean-Claude Maillol, on his experimental farm, in Murvielle-Lès-Montpellier.
Valentin Ehkirch / L’Express
Murviel’s experiment is encouraging, but it cannot be the miracle solution to the problem of water, which is not experienced in the same way throughout the territory. The Hérault, with its wide disparities in access to resources, illustrates the complexity of the issue well: around Montpellier fruit trees, market gardening and vines grow, while other corners of the department remain historically dry. Located just over an hour from the city centre, the heights of the Causse du Larzac are a good example. In Caylar, Mélanie and Sébastien Valancogne’s farm enjoys constant air. Between the hills stretches a karstic plateau where dry vegetation has taken up residence. The terrain is used to droughts, and at this time of year the landscape is revealed in shades of yellow. But, for the past few seasons, this couple of breeders, who arrived in 2014, have noticed an aggravation of the phenomena of drying out and heat waves. Sébastien Valancogne points to a cloud of dust rising above the pastures: “Look at that, it’s not good, it’s a sign that the ground is very dry.” Their breeding, a dozen cattle and twenty horses, requires letting the animals graze in these grassy plots. “Today the pastures are not keeping up, they are too dry”, breathes Sébastien.
Plant trees to respond to the drying up
“Farmers have always experienced years of more or less marked stress, but we have changed the regime: these climatic hazards are becoming the norm”, notes Philippe Debaeke, director of research in agroecology at Inrae. According to him, the agricultural France of the future could be divided in two: “Climate change will be more favorable for certain crops in the North, while the Mediterranean area will be a hotspot warming,” he warns.
The disparity and multiplicity of problems force farmers to resort to a thousand and one solutions to adapt. To respond to the drying up of their pastures, the Valancognes have chosen agroforestry. This winter, the couple planted 1,500 trees of around twenty species particularly suited to the local terrain. “We took hardy species, such as hawthorn or rose hips, which resist heat and drought well,” explains Mélanie. These hedges make it possible to recreate areas of shade and slow down the wind, while promoting the rise of humidity in the soil.
Sébastien Valancogne, in front of the hedges he planted with his wife Mélanie, in Caylar, on the Larzac plateau.
Valentin Ehkirch / L’Express
To think together, the couple also initiated with their neighbors breeders an economic and environmental interest group (GIEE). A structure dedicated to the study of climate change on their territory. “There are now around ten sheep and cattle breeders with whom we precisely document the impacts of climate change on our practice.” There is no doubt that the Valancogne have long been aware of ecology, but this group should also make it possible to convince farmers with practices that are less suited to future challenges. “Some see more or less far in their practice, and are more worried about these changes. The GIEE helps to ask the same questions and to experiment”, supports Sylvain Micola, project manager on pastoralism at the Chamber of Agriculture from Hérault and leader of the group.
Multitude of solutions
Far from the dry plateaus of Larzac, descending towards the south, the landscape changes again. To the east of Montpellier are vegetable crops and fruit trees. The region experienced a great transformation after the construction of the Bas-Rhône Languedoc canal, a project decided in the 1950s, which allowed agricultural diversification and urban growth, by diverting part of the water from the Rhône. It is here, in the commune of Mudaison, that Robert Cecchetti developed his activity. Passing between the hundreds of apple trees that line up in front of him, the 50-year-old farmer grabs a fruit hanging from a tree. He points to a brown spot on this still green apple. “It’s the result of the heat, during strong heat waves the damage can be much more serious,” he explains in a calm voice. The apple grower remembers well the heat episode of June 2019, France had then broken heat records: “It was 47 degrees in the shade, the fruits literally cooked on the tree in one afternoon. ”
Robert Cecchetti in his Mudaison orchard, a few kilometers from the center of Montpellier.
Valentin Ehkirch / L’Express
Here the main problem is not the lack of water, but the recurrence and intensity of climatic phenomena known for a long time. To maintain his operation in good health, Robert Cecchetti therefore uses different systems. Anti-hail nets have been in place for about ten years, windmills have recently been installed to lessen the effects of frost on apples. Above all, the irrigation has been reviewed: “Before, we watered over the trees with a sprinkler system, which consumes a lot of water, since then we have switched to drip”, explains the operator. . However, Robert Cecchetti keeps part of his orchard under sprinkler irrigation. “When we have big heat strokes, we can gain 2 or 3 degrees, and in winter it also serves to protect against frost.” Finally, adapting also requires successfully maintaining one’s activity in the face of changing demand. “The varieties that have best resisted the heat are not necessarily the favorites of consumers. This means that you can adapt, but you have to be sure to sell.” For farmers, this part of the problem always remains in the back of their minds.