LIFE CO2SAND: Improving sandy substrates with clay

Climate change may make cover sand substrates more acidic and dehydrated, with the result that today's agricultural functions are no longer possible. The participants within LIFE CO2SAND believe that they can make the substrates of arable land more resilient to climate change by adding clay to the sandy topsoil. The aim to treat 700 hectares of arable land with sandy substrates with clay, up to and including 2027, to increase the content of fine clay (lutite) to 8%.

The Province of Gelderland and Rijkswaterstaat are working closely together on the LIFE CO2SAND pilot project. Rijkswaterstaat aims to make its own large-scale earth-moving operations more sustainable, while the Province of Gelderland's focus is on making agriculture more sustainable.

Benefits of clay

Currently, clay that is found to be unsuitable for civil engineering projects is often reused to fill up former sand extraction pits, or for back-filling in projects. This approach does not use the potential benefits of clay as a soil conditioner in agriculture. Sandy soils could benefit in the following ways:

  • The ground will retain greater volumes of water over a longer period
  • Less nutrient run-off
  • Greater agricultural yield
  • Increase in nutrient availability for crops
  • Increase in organic material in the soil, and a possible result of more carbon being captured
  • Improvement in conditions for life in the soil

To add scientific credence to this, Wageningen University and Research and Eurofins are carrying out tests at de Marke experimental farm and various trial fields.

Encouraging municipalities with the soil-flow system dynamic model

The soil streams Buyer Group is developing new procurement requirements to encourage high-quality reuse in future procurement contracts. In this context, LIFE CO2SAND works with Copernicos to develop the dynamic model of the soil flow system. This model determines the circular value of excavated clay by linking it with solutions that municipalities can use. Policy makers, procurement teams and contractors can use the model as a decision-making tool at an early stage in projects.

The Environment and Planning Act (Omgevingswet) provides the opportunity to scale up initiatives like LIFE CO2SAND. We will help interested municipalities to set up their own environmental plans and soil quality maps. We will also work on methods to further facilitate the reuse of soil beyond the spatial scale of civil engineering projects.


July 2021 - June 2027

European programme


Project website



Rijkswaterstaat; Province of Gelderland; European Union; Wageningen University & Research; de Marke experimental farm