FOR IMMEDIATE RELEASE: Monday, April 25, 2016
Research Shows Phosphorus Accumulation in River Basins
Analyses will help determine future management of phosphorus in ag production
ST. PAUL, Minn. — An international group of scientists, including a researcher from the Minnesota Department of Agriculture, has estimated the long-term environmental impact of phosphorus, a chemical element of fertilizer, in three world river basins.
Fertilizers used in agricultural production can leak into waterways and until now, scientists have not had a good handle on how the phosphorous in the runoff accumulates and to what extent.
For the first time, researchers have come up with a way to estimate on a large scale, how phosphorus flows through an environment over many decades. By doing so, researchers are gaining a better understanding of how and where phosphorus accumulates.
“There has been growing concern about excess phosphorus in our water resources; long-term analyses enable us to explore the true causes and consequences. This understanding may assist in the development of implementation strategies supporting sustainable agricultural production and improved water quality protection” said Heidi Peterson, research scientist with the MDA, and co-author of the study.
Peterson and the team of 13 researchers studied three river basins where food and water security are directly linked to phosphorus. The analysis included the Thames River basin in the U.K., the Maumee River Basin in the mid-western section of the U.S. and the Yangtze River Basin in China.
The study areas ranged in size from approximately 5,000 to 700,000 square miles. Historical records dating back 70 years were used to measure the human impact on the flows of phosphorus into and out of each catchment through trade, food waste, human waste and agricultural runoff, comparing these flows to losses of P from each river's discharge. The results showed that massive amounts of phosphorus have accumulated in the landscape — a form of "legacy P" that may affect aquatic ecosystems for decades or even centuries.
The study’s novel analyses illustrate the challenges researchers face in figuring how to manage the storage, exploitation and reactivation of phosphorus that is already present in our environment.
The study’s findings appeared in the April 11, 2016 online issue of Nature Geoscience.
CONTACT: Margaret Hart, MDA Communications Director
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