
Dissolved nutrients selected as Dutch entry for Stockholm Junior Water Prize 2021
Student Stijn Wiersma of the Bornego College has won the Dutch Junior Water Prize for his study on the size of hay particles and the solubility of nutrients in water. His conclusion: size matters.
More nutrients for plants
For his secondary school graduation project, Wiersma studied the particle size of organic matter and the water solubility of nutrients. This relation is important for making fertilizer: the more nutrients dissolve, the more nutrients for the plants.
In his research he took hay as an example of organic material. Hay has a big potential for the agricultural industry.
For his research he grinded and dissolved hay. His expectation was in line with the outcome: smaller particles dissolve better in water. However, this is not always better for the soil. An excess of nutrients can lead to leaching.
‘The size of the particles will have to be adapted to the soil’, says Wiersma who is excited to start a follow-up research, especially on the use of hay as fertilizer in developing countries.


Grand finale in Stockholm
The jury was impressed by the relevance of the study and the potential for the international finale in Stockholm. As winner of the Dutch Junior Water Prize, Wiersma will represent the Netherlands in the Stockholm Junior Water Prize with contending junior researchers from over 30 countries.
The finale will take place during the online Stockholm World Water Week in late August.
Last year, secondary school students Nikki van Haasteren and Elise Hornstra represented the Netherlands with their research on purification of water using biomimicry.
The overall winner of the Stockholm Junior Water Prize 2020 was the Japanes duo Hiroki Matsuhashi and Takuma Miyaki who participated with a solution to combat soil erosion by using the traditional Japanese soil solidification technology Tataki to collect rainwater on farmland.