2023-12-27 13:46:00
“We don’t have the irrigation capacity for that, crops are in danger”: faced with drought, the struggle for farmers
The concept ? At the entrance to the meadow, where the watercourse enters, a 600 m long ditch (the canal) was dug, touching the stream. A simple lifting board allows you to free the entrance to the canal in order to bring in the water from the river. The watercourse is also equipped with a sort of dam or valve equipped with a crank, which can be lowered more or less high, in order to choose the quantity of water which will be kept in the river. The canal, about fifty centimeters wide, has a series of dams – in fact a simple metal plank that can be raised and lowered – allowing the water to overflow in sectors and therefore to cover the ground in front of him. The excess water returns to the stream. Everything works by gravity, the meadow being on a slight slope. No need for external energy…
The Pré aux Tambales in Cierreux has the only traditional irrigation system in operation in the Walloon Region. ©cameriere ennio
The only way to have fodder during harsh winters
Until ten years ago, only the ditch remained, where the trees had regrown. The field was fenced and accommodated livestock. Until Pierre Luxen, a fine connoisseur of traditional irrigation, and Henri d’Otreppe, owner of the meadow, met during Heritage Days, decided to recreate the place as it appeared in the 19th century and to restore the subsidence channel. “In the Ardennes, this type of irrigation has been done since the Middle Ages. It was a way of producing fodder, to be able to keep animals in winter, explains Pierre Luxen. The winters being harsh, fodder was needed and the only places where it could be produced was in the meadows, by irrigating them. We therefore brought water at the end of winter or in spring. In spring, we often experience kisses here (winds from the North and East, in Walloon “hales di mas”). It was during these cold and dry periods that water was brought. The spring water is 5-6 degrees: even if it froze at night or if there was a little snow, we irrigated and it warmed the soil. The vegetation therefore began to grow much earlier. We were thus able to have good fodder without adding fertilizer. Only the alluvium brought by the water fertilized the soil.” But this tradition was lost after the First World War, with the intensification of agriculture. “Larger plots were needed. In addition, most of these plots were on a slope, so everything had to be done by hand and not with machines. Most of these slopes which were mowed were therefore wooded with spruce. As for the wetlands, we did not know how to use the machines there, and the land was abandoned.”
Restoration of biodiversity
On their land, the Otreppe family could have been content to see “Christmas trees growing”, jokes Henri d’Otreppe, but, for them, reviving this activity, “it’s a way of highlighting a ancient technique as well as a natural heritage, rejoices his son Joachim, an agronomist engineer. Certain grass species will, for example, be favored over others.”
Farmer Bernard Thomas in the hayfield he farms in Cierreux using traditional irrigation. ©cameriere ennio
Nowadays, the primary advantage of traditional irrigation is in fact the redevelopment of biodiversity, according to Pierre Luxen: “Look, there is lanceolate plantain here,” he exclaims, pointing to a few shy leaves. at ground level, right next to the canal. It’s an indicator, if it starts to appear, it’s because the phosphorus is slowly leaving… If you want to simplify the soil, you enrich it, you add fertilizer, especially phosphorus. On the other hand, the poorer the soil, the more biodiversity there is. This is why we no longer bring livestock here, which enriched the soil with dung and urine. We only mow, twice a year: when you mow, you export the minerals present in the fodder and you impoverish the soil. Here, it may take another 5 or 10 years to recover the initial flora, but it is already much more diverse. Centaurea, bird’s-eye trefoil, lovewort, primrose, autumn colchicum… Everything is already there, but not yet in large quantities.” On the flooded soil, we also see earthworms swarming: “when we bring in water for irrigation, the earthworms come out. This is why we can observe the black stork or even the woodcock here: they come to help themselves!”, laughs Pierre Luxen.
Nearly 12.7 billion spent on environmental protection in 2021
Prohibited fertilizer
Traditional irrigation promotes the development of biodiversity, explains Pierre Luxen, agronomist engineer in charge of the Abissage canal restoration project. ©cameriere ennio
To preserve this biodiversity, the farmer, Bernard Thomas, cannot add fertilizer, apart from a little organic every five years. The yield in terms of fodder harvest is also lower but the farmer is financially compensated within the framework of agri-environmental measures. “What mainly interested me was trying this old technique again,” confides Bernard Thomas. In addition, we certainly collect significantly less but there are all kinds of flowers which can be used as natural dewormers for calves. These plants are not found in other meadows, in intensive agriculture. Here, the flora is natural… Moreover, if we have a drier month of March, we will see that it has been irrigated: it is much greener… The technique is therefore effective for a dry spring, on the other hand in the event of summer drought, this is no longer the case. If in summer there was water in the stream, we would do irrigation, it would be magnificent! But the stream, in summer, is completely dry…”
Indeed, the upstream source is not only surrounded by conifers, which pump the water, but it is also used for the exploitation of drinking water for the surrounding communities… The Cierreux meadow does not have the authorization from the Province to divert a third of the stream when it is at low water. If the stream is below this minimum level, irrigation will be prohibited.
Droughts and floods
In other countries where traditional irrigation is still alive over large areas such as in the Aosta Valley where water from torrents is used in summer, the availability of water upstream is also a concern, given among other things the announced disappearance of glaciers due to global warming. “In the Ardennes, if traditional irrigation is brought up to date, it will have to be adapted to climate change,” believes Pierre Luxen. It may be necessary to store water and give it more of a buffer role than irrigation. When there are periods with intense rains in a short time as is the case now every year, we could put water in the canal as I am doing. We could also very well imagine having areas where we store water, as we already do in the Walloon Region. In terms of flood prevention, it is also water that does not go down into the valleys and does not create damage or erosion but which is reused at the appropriate time, when it is dry. We have to be creative…”
The Tambales meadow. ©cameriere ennio
“Traditional irrigation also makes it possible to recharge groundwater,” adds Joachim d’Otreppe, agronomist and son of the owner. It keeps the water on site and promotes infiltration. We remove the water from the watercourse for a moment, we send it into the canals which will return it to the ground. So it has more time to sink in.” “It’s an extra sponge to capture water when we have too much and to recharge the water tables,” insists Bernard Thomas. And natural irrigation has made it possible to recover this wet meadow. In spring, it becomes a wet meadow again like it used to be…”
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