Dijken op de campus
Dijken op de campus

Future Dikes builds experimental dikes on Radboud campus

The research programme Future Dikes is researching how species-rich grass revetment can contribute to the erosion durability of a dike. A new research facility has been constructed at the Radboud University campus to make experiments with grass revetment possible.

The strength of the top layer of a dike depends on a combination of the soil particles, such as sand and clay, and the plants which grow on top of the dike and root in the dike. Part of the research takes place in a field on the dikes themselves. But dikes and their surroundings are variable. Weather, climate, maintenance and incidents make it difficult to do longitudinal experiments in which conditions remain stable or are intentionally manipulated. Hence a new research facility has been constructed at the Radboud University campus to make experiments with grass revetment possible.

Experimental dikes

Four experimental dikes have been built near the greenhouses on campus. A river dike has been recreated on scale, using the same clay soil as is used in strengthening the Wale dikes. The soil conditions and slopes are identical as well. This autumn, numerous species of plants will be sown on these experimental dikes in different combinations. This will hopefully show which mixture of seeds results in the fastest and best rooting. On 5 October, the experimental dikes were opened during a meeting with users and partners of the research programme, which is financed by the Hoogwaterbeschermingsprogramma (lit: High Water Protection Programme).

Future dikes op de campus

Looking underground

Next to the development of plants above ground, researchers are also strongly interested in what happens underground. The roots of plants keep the soil of a dike together in case of flooding, according to theory. To look underground, see-through tubes are buried in the dike to track the growth of roots with special scanners.

“It allows us to track how the rootage develops on a weekly basis, and how long it takes to reach certain depths. We can even take samples of the roots to analyse which roots belong to which species of plant. The great thing is that such species-rich revetment can stimulate plants to grow more and deeper roots.” – Dr Eric Visser, associate professor of Plant Ecology at Radboud University and researcher at Future Dikes. The tubes have been buried on different levels to monitor both the shallow and deeper growth of roots. This allows for a precise analysis of the development of the vegetation, which rooting belongs to which mixture, and which combinations of species result in the most rooted dike.

The experimental dikes will be on campus for a couple of years, allowing for a longer study of the development of the revetment. From next year on, the influence of drought on the different sow mixtures will also be studied.

Contact information

For further information, please contact one of the scientists involved or team Science communication via +31 24 361 6000 or media [at] ru.nl (media[at]ru[dot]nl).  

Sustainability, Nature