1. Team Meeting #5, Great Lakes Protection Fund Grant A Phosphorus Soil Test Metric To Reduce Dissolved Phosphorus Loading to Lake Erie Heidelberg University July 23 and 24, 2013 Observations from the rivers: Implications of bioavailability, particulate P delivery, and seasonality David Baker Project Director

2. 1. Bioavailable Phosphorus Export at Lake Erie Loading Stations 2. Particulate Phosphorus Delivery: Loading Station to Lake 3.Observations of direct P fertilizer runoff 4. Seasonal aspects of precipitation, discharge and loading Topics

3. The Study Area: From Waterville to the Western Basin Study Topics 1. Trends in bioavailable P export at the Maumee Loading station. 2. Transport of Bioavailable P from Waterville to the Western Basin during storm events. Waterville tributary loading station for the Maumee River

4. Total Phosphorus = Total Particulate Phosphorus + Total Dissolved Phosphorus Total Bioavailable Phosphorus = Bioavailable Particulate Phosphorus + Bioavailable Dissolved Phosphorus Dissolved Reactive Phosphorus Routine analyses at Heidelberg Bioavailable P studies at Heidelberg Major forms of phosphorus in river samples Focus on Storm Runoff Samples

5. Dissolved Phosphorus Annual Loads Total Dissolved P TDP Y = DRP Y x (TDP FWMC /DRP FWMC ) Y (TDP FWMC /DRP FWMC ) Y 1982 = 1.31 2010 = 1.10 Bioavailable Dissolved P (DHP) BDP Y = TDP Y x (DHP FWMC /TDP FWMC ) Y (DHP FWMC /TDP FWMC ) Y 1982 = 0.91 2010 = 0.97

6. Particulate Phosphorus Annual Loads Total Particulate P TPP Y = TP Y - TDP Y Bioavailable Particulate P BPP Y = TPP Y x 0.27

7. Maumee River Annual Loads Total Phosphorus (TP) TP is directly measured Total Bioavailable Phosphorus (TBP) TBP Y = BPP Y + BDP Y

8. Maumee River at Waterville, Average Annual Loads, 2023-2012 Total Phosphorus 2,437 metric tons per year Bioavailable Phosphorus 1,098 metric tons per year 45 % of Maumee TP is bioavailable

9. Maumee River at Waterville, Average Annual Loads, 2023-2012 Total Phosphorus 2,437 metric tons per year 33 % of Maumee TP is bioavailable at lake Bioavailable P Delivered to Lake Assumes 33% Delivery of PP 772 metric tons per year

10. Total Phosphorus Annual Load = 608 metric tons 1.88 kg/ha (1.67 lbs/acre) 70 % total particulate P (1.17 lbs/acre) 30 % total dissolved P (0.50 lbs/acre) Total Bioavailable Phosphorus Annual Load = 296 metric tons 0.91 kg/ha (0.82 lbs/acre) 43% bioavailable particulate P (0.32 lbs/acre) 57% bioavailable dissolved P (0.47 lbs/acre) TMDLs Nutrient Trading Target Loads Average Annual Loads 2003-2012, Sandusky River at Fremont

11. 3.Observations of direct P fertilizer runoff

12. Winter Broadcasting of fertilizer in the Lost Creek Watershed, 2010

13. . Dates custom applicators were in fields Some Fall Runoff Events from Honey Creek

14. 4. Seasonal aspects of precipitation, discharge and loading

15. March 1-June 30 load 20102011

16. Sandusky River Data

19. Total Phosphorus 08/28/2007 – Bridgeman (6 stations) 08/29/2007 – Landsat Image 08/30/2007 – Vincent Transect 0.083 0.100 0.062 0.113 0.066 0.139 0.100 0.206 0.105 0.181 0.053 0.107 DRP TP

20. 08/28/2007 – Bridgeman (6 stations) 08/29/2007 – Landsat Image 08/30/2007 – Vincent Transect Dissolved Reactive P.