Iowa Public Television


Freshwater Lake Pollution Blamed on Fertilizer

posted on June 17, 2005

Routine application of fertilizer may well be more damaging to freshwater lakes than previously believed. The buildup of chemicals, mostly phosphorus, is being blamed for fish kills and algae growth in Wisconsin lakes. A paper released this week by University of Wisconsin-Madison Professor Stephen Carpenter points the finger squarely at the use of chemical and natural fertilizers by industrial agriculture since the 1940s.

The Wisconsin Farm Bureau Federation disagrees with the conclusions of the report. According to Paul Zimmerman, Executive Director of Governmental Relations for the WFBF, farmers have improved soil conservation over the last two decades to make sure more dirt remains in place. Zimmerman blames dams that have made lakes more stagnant for some of the problem.

Carpenter's study concludes with a call for the use of various technologies to reduce or eliminate the problem. Suggestions included manure digesters to create sludge that could be sent to landfills, buffer strips to filter field runoff and the incorporation of new technologies to remove phosphorus from the soil.

Tags: lakes news pollution water quality