GYPREG - reduce nutrient leaching from agricultural lands with gypsum

There is a lack of effective methods to reduce nutrient leaching from agricultural land, especially phosphorus and particularly in organic farming. In addition to increasing the need for more fertilizers to maintain production, nutrient leaching cause significant problems when nutrients leach into watercourses, leading to eutrophication and, consequently, algal blooms and other problems. Therefore, to restore the Baltic Sea's ecosystem, it is crucial to decrease nutrient leakage from agricultural land.

The addition of gypsum to farmland can reduce phosphorus leaching by increasing aggregate stability, allowing the soil to more efficiently bind phosphorus. In Finland, large quantities of gypsum are produced as a byproduct of synthetic fertilizer production. Thanks to this, several large-scale projects have been conducted in Finland, such as SAVE, demonstrating that gypsum can significant reduce phosphorus leaching, even on the water catchment scale.

The GYPREG project, co-funded by the EU's Interreg Baltic Sea Region program, aims to test and demonstrate the possibilities of using gypsum on farmland in other countries around the Baltic Sea, such as Sweden, Poland, Latvia, and Lithuania.

In Sweden, we will:

1. Transfer knowledge from the Finnish experiments to Swedish stakeholders translated into Swedish.
2. Conduct a GIS analysis of the areas where it is most relevant to use gypsum on farmland.
3. Perform laboratory experiments testing the effects of gypsum and gypsum/lime mixtures on Swedish soils.
4. Conduct field trials with gypsum.
5. Carry out demonstrations for Swedish stakeholders.

To promote the Baltic Sea day 29-08-2024 the GYPREG-project arranged a field visit to Sättragården outside Upplands-Väsby. Participating was the Crown Princess Victoria who took the opportunity to try spreading gypsum both by hand and tractor and to see the fast binding effect of gypsum on clay soils. See a movie of the visit here.