Vermiculite addition to soil decreases N water pollution by over 30%

The large amounts of nitrogen-containing mineral fertilisers in industrial agriculture are leading to water pollution with effects such as eutrophication and death of aquatic life. There is therefore a need for techniques to keep N in the soil to prevent leaching in waters. Here, we tested the effect of the addition of vermiculite, a phyllosilicate mineral, to the soil, on fertiliser NH₄ ⁺-N retention in laboratory experiments during 14–45 days. The added amount of vermiculite was twice the amount of the nitrogen fertilizer added. Our results show that addition of vermiculite increases NH₄ ⁺-N retention by over 30%, compared to a control. Adding vermiculite is thus a promising technique to control the eutrophication of water systems as well as reducing agriculture cost.