Have we reached a tipping point for phosphorus saturation?

CLG-BannerImages-180213-04Phosphorus is one of the main nutrients of focus in the Iowa Nutrient Reduction Strategy. It is essential to the growth of plants, but when phosphorus enters our water bodies it leads to excessive plant growth and increases in toxic algae that are harmful to human and animal health.

A recent study from the University of Montreal quantified, for the first time, the maximum amount of phosphorus that can accumulate within the watershed before additional pollution is released into the water.

Their results indicate a relatively low threshold compared to current application rates and notes that tipping points could be reached in less than a decade.

Research supervisor, Roxane Maranger, aquatic ecosystem ecologist at University of Montreal, compared the relationship of the land and phosphorus accumulation like this:

“Think of the land as a sponge,” Maranger said. “After a while, sponges that absorb too much water will leak. In the case of phosphorus, the landscape absorbs it year after year after year, and after a while, its retention capacity is reduced. At that point historical phosphorus inputs contribute more to what reaches our water.”

Be sure to read the full article to learn how they conducted the study and further implications of the results.

Locally, the implementation of nutrient reduction strategy practices like no-till, cover crops, phosphorus application management, perennial vegetation, buffers and more are imperative to the long-term sustainability on our water resources.

Liz Juchems