Eagle Creek Watershed Project
A well-documented threat to human and environmental health comes from agricultural runoff, water containing phosphorus and nitrogen fertilizers leaving farm fields and entering lakes and rivers. While there are a number of concerns around contaminated agricultural runoff, a primary issue is that algae growth dramatically increases when it is exposed to these excess nutrients. The algal bloom that results chokes out natural vegetation by consuming all of the oxygen in the water and creating “dead zones” in which most animal life cannot exist. Sometimes the algae also generates toxic substances that are harmful to people, resulting in closed beaches and the elimination of other recreational opportunities.
The Eagle Creek reservoir is one of the primary drinking water sources and recreational areas in the Indianapolis metropolitan area. The watershed that feeds it is also heavily farmed, and the integrity of the reservoir’s water quality is a primary management concern.
Greenleaf Communities is currently overseeing field-scale research into farm management practices that could help to reduce the amount of phosphorus and nitrogen lost from the farm fields into the watershed. Primarily, we are studying the use of gypsum as a soil amendment for watershed environmental benefits. Additional benefits of the research include improving soil health and reducing erosion while increasing crop yields and providing an economic incentive for farmers to participate.
Our research is being led by Dr. Pierre Jacinthe, Associate Professor of Earth Science at Indiana University-Purdue University Indianapolis, and is being conducted on working farm fields Brownsburg, IN in the threatened Eagle Creek watershed. Fields with historic use of gypsum applications are being compared to fields with similar soil types, crops, and other management practices, but no history of gypsum use. Soil and water samples are collected regularly to compare the movement of nutrients (fertilizers) from the field and into the drainage ditches that eventually lead into Eagle Creek Reservoir.
It is helping to define best management practices that will be used by farmers and soil conservationists across the country to improve soil and water conditions and environmental integrity.
Excess nutrients run off fields into waterways where they contribute to toxic algal blooms that threaten public health, as well as eutrophication that harms aquatic life. One best practice that improves soil conditions is the use of calcium sulfate (gypsum) as a soil amendment; it improves nutrient uptake by the plants and reduces loss from the fields into the waterways.