Grassland irrigation
Inspiration from an age-old agricultural technique
Irrigating grassland is an age-old agricultural technique in which flowing water is led to the grassland through ditches with the aim of promoting growth and increasing hay yield. Only gravity and natural flow are used. Irrigation is mainly done in winter and spring. It prevents freezing, combats pests, improves soil structure, and supplies mineral-rich sludge.
For the Water & Land project we worked together with grassland irrigation communities from Lommel (BE), Mol (BE) and Lankheet (NL). In both Flanders and the Netherlands, this intangible heritage practice has been added to the Inventory for intangible cultural heritage. An international network campaigned for and succeeded in the recognition of the craftsmanship on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity.
In large parts of Europe, grassland was irrigated from the early Middle Ages until well into the twentieth century. This was originally a form of fertilization, but today it mainly produces grasslands characterized by their biodiversity. CAG and KIEN went into the water meadows and spoke to the heritage communities. The positive effect of irrigation on soil and biodiversity was emphasized each time. Grassland irrigation prevents freezing, combats pests, improves soil structure and supplies mineral-rich sludge. Administrators and academic researchers also agreed, and together we investigated what opportunities exist from intangible heritage for local climate action, climate adaptation, and in the field of ecological sustainability in general.
Although traditional irrigation is sometimes seen as a technique of the past, communities are actually working on very topical things.
– Eric Brinckmann
Traditionally irrigated grassland stands out for several reasons. They are always species-rich, and dozens or even hundreds of native plant species can be discovered there. Moreover, these grasslands not only contain local species, but also species that travel with the water or those that are more likely to be expected in more calcareous environments. These effects on biodiversity have a deeper cause. After all, biodiversity on the surface is related to that in the soil. The healthier the soil life, the more organic matter is converted, and more plant life can then be extracted from the soil. Grassland irrigation ensures that the phosphate, nitrogen, potassium, calcium and humus content of the soil is high, making it ideal for soil life and fertility. In addition, years of irrigation forms a sludge layer that is 10 to 20 cm thick in some places. This sludge layer reduces symptoms of drying out in the soil and ensures better water storage.
Grassland irrigation, just as knowledge about and management of watermill landscapes, can be very valuable in terms of rewetting the environment and raising the groundwater level. This is one of the increasingly recurring problems in the current challenge regarding the climate. The water that flows over irrigated grasslands has time to infiltrate the soil. In the fight against drought, grassland irrigation is a method that can be applied not only in large stream valleys and in former drainage meadows, but also beyond.
Grassland irrigation can be compared to the restoration of wetlands such as swamp areas or wet woods. We can store an enormous amount of water in our soil, it simply needs to be given time to infiltrate.
– Hans Nuyttens
Moreover, the wet environment of the water meadows is extremely suitable for carbon storage: they retain a lot of CO2. In addition, these irrigation systems ensure that water, which now falls much more often during peak periods, can be retained very effectively. The irrigation infrastructure can therefore also be used for water storage. Finally, practical knowledge about guiding water through ditches and streams, and the associated maintenance of these watercourses, can provide inspiration.
The technique of traditional grassland irrigation does not necessarily have to be adopted by one and all, on the contrary, intangible heritage is eminently dynamic and adapts to society and prevailing circumstances. Heritage can also simply serve as a source of inspiration for nature-based solutions, for example for the design of tidal areas along rivers. The history of the landscape and the intangible heritage that accompanies it can form the basis for technologically new, yet old solutions.
And in the future?
There are new applications for the technology of traditional grassland irrigation for rewetting or waterlogging. Yet converting these ideas into practice is not easy. Traditional grassland irrigation is labour intensive, and restoring former irrigation systems requires budgetary efforts. In addition, landowners, volunteers and farmers are needed who are open to (re)using the technology. You can read how we can value and validate this intangible heritage on the 'educational past' page.
