Helping Farmers Help Watersheds

Plants and animals need phosphorus to thrive, but when farming practices cause an increase of this nutrient in streams, rivers, and lakes, aquatic algae and other plants take advantage. Blooms of algae can spoil the natural balance of aquatic ecosystems and interfere with sources of drinking water.

The process whereby increases in nutrients lead to over-abundance of algae and other plants is called “eutrophication.” In 2007, Dr. Christine Shoemaker of Cornell University’s Department of Civil and Environmental Engineering, received a $100,000 CARTI grant to improve the ability to understand and manage eutrophication in water bodies in Upstate New York due to excess phosphorus. The project is a collaboration with Cornell’s Department of Earth and Atmospheric Science.

Shoemaker, a SyracuseCoE associate, is a mathematician, engineer, ecologist, and water management expert, who is studying the impact of farming on phosphorus levels in watersheds that supply New York and other cities with drinking water.

A major issue is how to reduce phosphorus that enters water from cattle feed. Most of this phosphorus enters the ecosystem as cattle manure that is applied to farmland. Farmers often feed their livestock more nutrients than they need for optimal health. Research by the New York State Department of Environmental Conservation shows that farm phosphorus runoff can be reduced by 30% through a “whole-farm plan.”

“Earlier work by my colleagues and I indicates that if farming best-management practices are not implemented, phosphorus levels are going to increase, because there is more phosphorus going into the watershed than is leaving it,” explains Shoemaker, who, along with her students, has developed a computer model to track water, sediment, and phosphorus in the 47-square-mile Cannonsville watershed, one of four reservoirs in the Delaware watershed system that supplies New York City.