LIFE CO2SAND

Using clay to make farmland climate proof
Last modified: 5-September-2024

As a result of climate change we increasingly see longer periods of drought or, on the other hand, extreme rainfall. This has a great impact on farmers on sandy soils. Clay soil enhances the resilience of sandy soil, strengthening its capacity to handle extreme weather conditions.  Clay can also increase the fertility of sandy soil. In the LIFE CO2SAND, Rijkswaterstaat, (the Dutch Directorate-General for Public Works and Water Management) and the Province of Gelderland match the supply and demand of clay soil. We are applying the ‘clay-in-sand’ principle in demo fields. Farmers, area managers and land designers are welcome to visit these ‘field labs’ and make use of this technique for their own soil.

Clay for sandy soil: demand finds supply 

Farmers need to improve the quality of their farmland. There is a surplus of clay soil, which is not used at this time. In lowland areas, clay is extracted in nature restoration works and area development for road & house building. This clay is suitable to improve drought-sensitive sandy soils of farmers. The clay particles enable the soil to retain more water, organic matter and minerals. More organic matter in the soil goes with a reduction of greenhouse gasses in the atmosphere. This helps to slow down climate change. 

700 hectares of climate-proof agricultural land by 2027

We transport clay that is released in creating nature areas and in building roads and houses, to drought-prone sandy soils of farmers. 

The approach: 

We assess the quality of a parcel. Together with the farmer we determine which clay is most suitable and how much clay we need to sustainably improve their soil.
We work with demo fields. Each demo field is different and each farmer works differently. This enables us to gain experience with different local circumstances, clay types and ways of applying the clay.
On the demo fields we measure how much extra water the soil retains through the clay, and the change in soil fertility. We also measure differences in organic substance levels between the treated fields and untreated soil.
We engage with policymakers and land developers responsible for clay releasing projects to promote the inclusion of clay delivery to farmers in planning studies and tendering procedures.
We share knowledge with farmers, researchers and authorities by publications, demo days, congresses and calls.
We develop education kits for business consultants and agricultural schools.
We assess the quality of a parcel. Together with the farmer we determine which clay is most suitable and how much clay we need to sustainably improve their soil.
We work with demo fields. Each demo field is different and each farmer works differently. This enables us to gain experience with different local circumstances, clay types and ways of applying the clay.
On the demo fields we measure how much extra water the soil retains through the clay, and the change in soil fertility. We also measure differences in organic substance levels between the treated fields and untreated soil.
We engage with policymakers and land developers responsible for clay releasing projects to promote the inclusion of clay delivery to farmers in planning studies and tendering procedures.
We share knowledge with farmers, researchers and authorities by publications, demo days, congresses and calls.
We develop education kits for business consultants and agricultural schools.

What results do we have? 

  • In 2021 we started with 5 demo fields; 4 in Gelderland and 1 in Brabant. In 2023 a demo field was added in Overijssel. 
  • Meanwhile, 1 or more layers of clay have been applied to 33 plots with a total area of 185 hectares. The target is 700 hectares by 2027.  
  • On 37 hectares, the target of 8% lutum in topsoil has been reached.  
  • Soil fertility has demonstrably improved: higher binding capacity due to a larger clay-humus complex (CEC, Cation Exchange Capacity). 
  • Better resistance to leaf yellowing disease observed.
  • The acidity decreases, making the soil more fertile.
  • Roots actively seek the clay: rooting is visible in clay clods. The crop absorbs water and nutrients from the clay. 
  • The treated plots are considered more climate-robust because they can retain more organic matter thanks to the clay. 
  • Already, nearly 85,000 m3 of clay soil has been high-value reused for agriculture. 
  • Since 2021, we organised 14 demo days and received a total of over 500 farmers on the demo fields.   
  • In the long term we can expect an extra retention of 1.9 tonnes of CO2-equivalents per hectare per year.

Sand belt

The South and East of the Netherlands are part of the European ‘sand belt’. This belt is covered with sandy soils that are prone to droughts. The belt runs from Flanders in Belgium to Belarus and has intensive agricultural use. This is the target area of LIFE CO2SAND.

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Contact

For any questions or additional information, please feel free to contact us by telephone: +31 (0)26 359 99 99 or e-mail.

LIFE CO2SAND received financing from the LIFE programme of the European Union. Rijkswaterstaat is project partner.

LifeRijkswaterstaat Ministry of Infrastructure and Water Management