What is it about?

We developed a model to understand phosphorus (P) dynamics for the entire drainage basin of the Baltic Sea since 1900. This model included a rapid transport pathway that represented sources such as runoff from cropland and a slow pathway that represented leakage from mobile legacy sources. The model suggests that loss from the mobile pool contributes about half of current waterborne inputs to the sea; as a result, it could be difficult to make substantial near-term reductions. However, there are opportunities to meet environmental goals by slowing the accumulation of P in the landscape and by implementing measures that address the rapid transport pathway, such runoff from cropland, and the mobile stores, such as cropland with large soil-P reserves.

Featured Image

Why is it important?

All life depends on phosphorus (P), which is why it is an important crop fertilizer. Humans generally consume more P than needed and the excess ends up in sewage systems. Past management of P in fertilizer and human sewage has led to the accumulation of P in soils and sediments of lakes and streams. This accumulation is called “legacy” P because it can leak for decades to downstream lakes and coastal areas where it contributes to environmental problems.

Perspectives

For me personally, this paper is exciting because it is the first model (that I know of) that describes the extent to which legacy phosphorus can "leak" into surface waters, in this case, the Baltic Sea. A number of scientific studies have discussed the potential for phosphorus to accumulate and leak, but modeling these dynamics has been challenging. Our findings show the importance of having a long term perspective (i.g. being patient), when managing nutrients.

Dr Michelle L McCrackin
Stockholm University

Read the Original

This page is a summary of: A Century of Legacy Phosphorus Dynamics in a Large Drainage Basin, Global Biogeochemical Cycles, July 2018, American Geophysical Union (AGU),
DOI: 10.1029/2018gb005914.
You can read the full text:

Read

Contributors

The following have contributed to this page