Tuesday, September 11th, 2012
Researcher says years of data needed
Water monitoring stations
By Nancy Allen
CHICKASAW - A USDA researcher says he would like to get 20 years worth of data from water monitoring stations to see which conservation practices work best at keeping nutrients on farmland and out of waterways.
The biggest dam may be funding.
Kevin King of USDA's Agricultural Research Service talked about eight edge-of-field water stations - two in the Wabash River Watershed and six in the Grand Lake Watershed - at Monday's Ag Solutions meeting in Chickasaw. Ag Solutions, a nonprofit farmer-led group, is trying to develop cost-effective solutions to lessen the runoff of phosphorous, the main nutrient feeding toxin-producing algae blooms in Grand Lake.
The stations measure the levels of phosphorous and nitrogen in surface water and tile water leaving farm fields.
"It's imperative to have long-term data to have it be credible and scientifically sound," King said. "It would be good to have data over at least 20 years."
Installation of seven of the stations was funded with USDA funds in the Mississippi River Basin Initiative and one with funds from Ohio EPA's research and development office.
Each station cost $25,000 to install and will take about $6,000 per year to maintain and operate, King said. There is no guarantee federal funds will be available in the future to operate the stations and gather data; that is a concern, he said.
The six stations in the Grand Lake Watershed were installed beginning in April and the two in the Wabash River Watershed were installed last year. There has not been enough rain to gather any conclusive data yet, King said.
Baseline data will be gathered for the first few years with farmers participating in the study and then installing various conservation practices every few years. It will take two to three years after a conservation practice has been installed to gather data to help determine whether it is working, King said. Researchers will look at the impacts of single and multiple practices.
Determining how phosphorous is leaving farms should help determine which conservation practices to use to stop it, he said. Existing studies on how water moves through farm tile are limited, he added.
"You have to understand the mechanism; is it a surface runoff problem or is it a tile problem," King added.
Different practices researchers plan to test include water table management using tile stops; cover crops; how, when and by what method manure and commercial fertilizer is applied; end-of-field tile filters to capture nutrients before they leave farmland; land application of gypsum to lower phosphorous levels; variable rate application of fertilizer; and no-till verses rotational tillage.
"We'll look to the farmers for new things to test too," he said. "They're the innovators."
Existing studies show the longer it takes the water to filter through the soil before it reaches a tile, the more phosphorous is taken out of the water.
"It's a soil quality issue," he said. "If we can make this water ... go through a torturous path before it gets to the tile, the better off we'll be."
Soil with deep cracks can be corrected by planting cover crops or by tillage, he said.
"Our ultimate goal is to understand if it's tile or surface water that is the primary transport mechanism of excess phosphorous and what best management practices exist or can we test to try to address those," he said. "The edge of field data is invaluable."
About a dozen farmers attended the meeting to listen to King's presentation.
King said next month he will help install a wood chip bio-reactor in a field tile at St. Charles Center. The tile is near a wetland and a cattle lot that has had manure runoff problems. The bio-reactor converts nitrates into a gas released into the air and captures phosphorous in a filter containing a slag (steel) aggregate. The technology was created by Aleksandra Driso, a research professor at the University of Vermont.