|Task Force II releases final reports|
|Wednesday, November 20, 2013 9:14 PM|
James J. Hoorman
The Ohio Lake Erie Phosphorus (P) Task Force II released its final report in October and there are a lot of interesting facts on phosphorus runoff and possible changes that may be coming in farming practices. This article summarizes and highlights major findings from the P Task Force.
The P Task Force is composed of representatives from Ohio EPA, Ohio Department of Natural Resources, Ohio Lake Erie Commission, and agribusiness, crop consultants and farmers. The purpose of the P Task force is to track and reduce soluble reactive phosphorus in Lake Erie and to develop policy and management recommendations based on new data and research. (pg 1)
P Task Force key findings: “Nutrient impairment is impacting the $11.5 tourism industry and causing increased costs to public water supplies.” (pg 1) Approximately 10 million people get their drinking water from Lake Erie.
“The Task Force concluded that there are multiple contributors to P in Lake Erie but agriculture is the leading source … in the Maumee River (~80 percent).” (pg 1)
A NRCS Great Lakes Conservation Effects Assessment report includes the following highlights in the P Task Force report:
“Eighty–four percent of P applied in agriculture came from fertilizer and 16 percent from manure. Lake Erie receives 44 percent of all P delivered in the Great Lakes. Cultivated Cropland contributes 61 percent of the total P delivered to Lake Erie. Average annual loads of P delivered from edge of fields is 2.05 #/A and from outlets is 1.43 #/A. Existing conservation practices are reducing edge of field P losses by 32 percent.” (pg 5) Ideally, a P loss of 1 pound or less per acre is desirable.
The Task force also reported that “the relative contribution of dissolved reactive P from turf to Lake Erie is low; however, recently the Scotts Company eliminated P from their lawn maintenance products resulting in an annual reduction 158 tons of P.” (pg 10)
To reduce harmful algae blooms (HAB) in Lake Erie, the task force set some targets for P reduction in the water entering Lake Erie.
“For total P, reductions of 37 percent (from 1,275 metric ton down to 800 metric ton) during the spring months (March 1-June30). For dissolved reactive P, a 41 percent reduction (256 metric tons down to 150 metric tons) in the spring will significantly reduce or eliminated HAB’s.” (pg 34)
Several best management practices are being promoted by the P Task Force: “Soil tests every three years representing no more than 25 acres. Recommend using intense precision technologies with GPS on as many acres as possible. No surface applications of P fertilizer on snow covered or frozen ground. Nutrients should be incorporated or banded and injected or applied to a living crop. Weather predictions and soil conditions should be considered to minimize runoff.” (pg 51)
“Including cover crops is critical to improving soil health, increasing water infiltration, and reducing critical peak runoff that is transporting sediment and dissolved nutrients. Improved crop rotations decrease surface runoff through better water infiltration and water holding capacity and decrease runoff and soil erosion.” (pg 52)
Residue and tillage management are critical components. “Mulch till and no-till are critical conservation practices to control erosion in the Western Lake Erie Basin. Recent information indicates that a combination of no-till, strip fertilization, and cover crops dramatically reduces runoff and nutrient movement especially on heavy clay soils that compact easily and seal off, even under no-till or rotational no-till (no-till one year, chiseling or vertical tillage the next) situations. These practices are important for climate change and sequestering carbon in the soil profile.” (pg 52)
Other practices that are being promoted: Grass water ways, drainage water management, filter strips/filter areas, constructed wetlands, blind inlets, phosphorus and denitrifying bioreactors, water sediment control basins, riparian forest buffers. (pg 52-54) The entire 96-page P Task Force report can be found at epa.state.oh.us/portals/35/lakeerie/ptaskforce2/Task_Force_Report_October_2013.pdf.
There is no “one” practice that can be recommended as best in all cases. Weather and management are key elements in the success of best management practices that reduce runoff, soil erosion and nutrient losses from fields!