Dan Mullen (CC BY-NC-ND 2.0)

Series: Phosphorus In Wisconsin's Land And Water

Phosphorus is an essential building block of life, but it's also one of the world's most common and troublesome pollutants. Intensive agriculture unleashes excess levels of phosphorus in the form of manure and other fertilizers. What plants don't consume of this essential nutrient lingers on the ground or makes its way down into soil. Rain pushes this phosphorus into streams, rivers, lakes and groundwater. When too much enters a body of water, it can fuel blooms of noxious and sometimes toxic microorganisms — a frequent problem in lakes around Wisconsin and in the Great Lakes. Farmers, scientists, environmentalists, and state and local officials are struggling to reach a consensus about how to manage this nutrient pollution while maintaining a robust agricultural industry.
 
In a startling turn-about, Lake Superior has lost its championship title as the clearest of the Great Lakes.
Phosphorus is one of the most important components in the ongoing struggle to balance agricultural prosperity with water quality. What scientists call "legacy phosphorus" — or "legacy P," a common abbreviation — exists in a sort of nutrient limbo.
Phosphorus has always been a big part of just about any water-quality discussion, including those about its levels in the Great Lakes. It also intersects with another big ecological problem in the lakes: invasive species.
The city of Waukesha takes pride in its wastewater treatment plant.
The U.S. Environmental Protection Agency has approved a Wisconsin program that backers say will give the state more flexibility in meeting standards aimed at reducing algae growth in waterways.
It looks like Wisconsin will be counting on more animal waste digesters to handle the growing amount of cow manure at large dairy farms.
There may be a way to prevent harmful blooms of algae in some lakes or reservoirs, according to a new study.
The state of Wisconsin is betting on manure digesters in rural northeastern Wisconsin to curb water pollution and other environmental problems linked to the spreading of manure on dairy farms.
Joe Stapleton owns a farm near Spring Green, Wisconsin. He's a conventional farmer, so he does use some chemical herbicides and fertilizers on the fields where he grows corn, soybeans and alfalfa.
One organism, exploding in population, thrives at the expense of others in its ecosystem. That's essentially what happens when a toxic algal bloom spreads a slimy, stinky trail across a body of water.