About Nutri2Forest project

Nutrient runoff, particularly phosphorus leakage from both agricultural and forest areas, is a common environmental challenge across Central Baltic countries. In forestry, phosphorus losses occur mainly on fertile, organic soils and where clear-cuts have taken place. Forestry clear-cuts caused by climate-induced pests and diseases, as well as conventional agricultural drainage practices, result in increased phosphorus transport into ditches, streams, lakes and ultimately to the coastal seas.

In agriculture, nutrient-rich soils under intensive use also contribute to phosphorus runoff, especially where drainage and fertilization practices are not aligned with circular economy principles. Wetlands and sedimentation basins, built to mitigate nutrient load from forestry and agriculture are often treated as waste endpoints rather than resources, thereby increasing eutrophication in shared water bodies, including lakes, rivers, and the Baltic Sea.

The Nutri2Forest project pilots a nature-based, circular solution that recovers phosphorus from drainage water from agriculture and forestry before it enters to natural water bodies. Modular filter systems with mineral-based sorbents will be installed in existing drainage systems, in e.g., ditches and sedimentation basins, targeting both agricultural runoff and runoff from fertile, organic forest soils where clear-cuts cause significant phosphorus leaching. These filters will be field-tested in four pilot sites (two in Latvia, two in Finland) representing the main runoff conditions in the Central Baltic region.

Unlike conventional approaches using iron or lime, the selected mineral sorbents not only capture dissolved phosphorus effectively but also allow safe reuse of the saturated material. After saturation/treatment, the phosphorus-rich filter material will be reused as a soil amendment substance in degraded or nutrient-poor forest soils.

Nutri2Forest projects main result is a fully tested, cross-border phosphorus recovery and reuse cycle demonstrated at field scale. The result includes tested filter prototypes, protocols for reuse of phosphorus-rich materials, and validated economic and environmental benefits. The solution turns sedimentation basins into circular resource hubs (decreased amount of waste), which can be replicated across the Central Baltic region.