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LaMP Presentation, David Baker
This document summarizes a presentation on phosphorus loading trends in Lake Erie. It finds that while point source phosphorus loads have significantly decreased due to sewage treatment upgrades, nonpoint source loads from agricultural runoff have not declined as sharply and show more annual variability. Specifically, the Maumee and Sandusky Rivers in Ohio export high levels of dissolved reactive phosphorus due to accumulation in surface soils under no-till practices. Reducing soil test phosphorus levels could help lower phosphorus losses to runoff.
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- 1. Lake Erie LaMPPublic Forum, Erie, PA November 6-7, 2009 Recent Trends in Phosphorus Loading to Lake Erie: Role of Changing Agricultural Production Practices David Baker, Senior Research Scientist National Center for Water Quality Research Heidelberg University, Tiffin, OH
- 2. Phosphorus: A majorproblem for Lake Erie 1. Sources: Point and Nonpoint 2. Forms of Phosphorus: Particulate and Dissolved Particulate + Dissolved = Total Phosphorus 3. Bioavailability of Phosphorus: Particulate ~ 30% Dissolved ~ 100% 4. Loading characteristics: Point sources -- ~ constant daily rate Nonpoint sources – pulsed during runoff events
- 3. The Lake ErieWatershed: Current Land Use Excessive phosphorus loads a primary cause
- 4. Total Phosphorus Loadsto Lake Erie 30,000 Lake Erie Target Load for Total Total Phosphorus, Metric Tons 25,000 Phosphorus set at 11,000 metric tons 20,000 15,000 10,000 5,000 0 1967 1972 1977 1982 1987 1992 1997 2002 2007 Water Year, 1967 - 2007 1. Obvious downward trend from 1967 – 1988. 2. From 1987 – 2007, trends, if present, much less certain.
- 5. Total Phosphorus Loadsto Lake Erie 30,000 Total Phosphorus, Metric Tons 25,000 20,000 15,000 10,000 5,000 0 1967 1972 1977 1982 1987 1992 1997 2002 2007 Water Year, 1967 - 2007
- 6. What happened? Let’s take a closer look at phosphorus loading to Lake Erie -- Especially from Northwestern Ohio and the Sandusky and Maumee Rivers
- 7. What are themajor sources of phosphorus that enter Lake Erie? Lake Erie Total Phosphorus Loading by Major Source Lake Huron Atmosheric Point Source Nonpoint Source Unspecified 30,000 Total Phosphorus, metric tons 25,000 20,000 15,000 10,000 5,000 0 1967 1972 1977 1982 1987 1992 1997 2002 2007 Water Year, 1967-2007 Data from Rockwell and Dolan
- 8. 14000 Point Source Nonpoint Source 12000 Total Phosphorus, metric tons 10000 Phosphorus removal at municipal sewage treatment plants. 8000 An $8.8 billion dollar investment 6000 between 1972 and 1985. 4000 2000 0 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 2007 Rapid declines through 1982. Much slower declines from 1982 to 2007 Note the small year to year variability in point source loads
- 9. 14000 Point Source Nonpoint Source 12000 Total Phosphorus, metric tons 10000 8000 6000 4000 2000 0 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 2007 Note the large annual variability in nonpoint source phosphorus loading
- 10. Lake Erie PhosphorusLoads External Phosphorus Average Percent of Sources to Lake Erie Phosphorus Total 1981 – 2007 Water Load, Phosphorus Metric tons/yr Load Years (27 Years) Nonpoint sources 6,467 63.1% 3 Point sources 2,201 21.5% 1 Atmospheric Deposition 496 4.8% Upper Lakes 1,080 10.5% Total Average Annual Load 10,244 100%
- 11. Maumee River, TotalPhosphorus Export Rate TP export rate mtons/day 140 All Lake Erie Point Sources = 6.03 metric tons per day Total Phosphorus, metric tons/day 120 100 80 60 40 20 0 10/01 10/31 11/30 12/30 01/29 02/28 03/30 04/29 05/29 06/28 07/28 08/27 09/26 Date, 2007 Water Year For the total point sources entering Lake Erie from 1981 – 2007, the average daily load has been 6.03 metric tons per day
- 12. In July andAugust 2003, three major runoff events occurred in the August 18, Maumee River (left). 2003 That summer had the most severe blue-green algal blooms that had been observed in recent years. Maumee River 7/1/2003 - 8/22/2003 Flow, CFS TP, mg/L as P 50,000 0.800 45,000 0.700 40,000 0.600 35,000 Flow (cfs) 0.500 TP (mg/l) 30,000 25,000 0.400 % Point 20,000 0.300 Source P 15,000 0.200 10,000 5,000 0.100 Maumee 4.9% 0 0.000 Sandusky 2.8% 7/1/03 7/11/03 7/21/03 7/31/03 8/10/03 8/20/03 Date
- 13. Drainage to interconnecting channel Area = 22.4% point source P load = 55% nonpoint P load = 9% P load, all sources = 29% Drainage to western basin Area = 42.6% point source load = 20% Drainage to central and nonpoint P load = 71% eastern basins. P load, all sources = 48% Area = 35.0% point source P load = 25% nonpoint P load = 20% P load, all sources = 23%
- 14. PLUARG Final Report, 1980 Pollution from Land Use Activities Reference Group
- 15. Total Phosphorus Total Total Particulate Dissolved Phosphorus Phosphorus Agricultural Phosphorus Control Programs in the Lake Erie Basin No-till and reduced-till to reduce cropland erosion Conservation Reserve Program, take highly erosive land out of production Conservation Reserve Enhancement Program – buffer strips
- 17. Sandusky River, AnnualLoads Sandusky R., Total Phosphorus of Total Phosphorus Loads Sandusky River: Total Phosphorus Loads 1200 Total Phosphorus, metric tons 1000 800 600 Calculated Directly loads 400 measured 200 loads 0 1975 1980 1985 1990 1995 2000 2005 Water Year Sandusky River Fremont, Sandusky River, Fremont, Particulate of Particulate Phosphorus Annual Loads Phosphorus Loads Particulate Phosphorus Loads Dissolved Reactive Phosphorus Loads Annual Loads of Dissolved Phosphorus 1200 300 Particulate Phosphorus, metric 1000 Dissolved phosphorus, metric 250 800 200 tons tons 600 150 400 100 200 50 0 0 1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005 Water Year Water Year
- 18. Sandusky River Fremont, Sandusky River, Fremont, Particulate Phosphorus Loads Annual Loads of Particulate Phosphorus Dissolved Reactive Phos. Loads Annual Loads of Dissolved Phosphorus 1200 300 Particulate Phosphorus, metric Dissolved phosphorus, metric 1000 250 800 200 tons tons 600 150 400 100 200 50 0 0 1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005 Water Year Water Year Sandusky R., Bioavailable Phosphorus Loading Sandusky R. Bioavailable Phos. Loads Bioavallable Soluble Phos. Bioavailable Particulate Phos. 500 Bioavailabe Phos, metric tons 400 300 200 30% 100 110% bioavailable 0 bioavailable 1975 1980 1985 1990 1995 2000 2005 Water Year
- 19. Maumee River, AnnualLoads Maumee R., Annual Loading, Particulate Phosphorus Loads of Particulate Phosphorus Dissolved Dissolved Reactive Phosphorus Loads Reactive Phosphorus 3,500 1000 Particulate Phosphorus, metric 900 Phosphorus, metric tons 3,000 800 Dissolved Reactive 2,500 700 2,000 600 tons 500 1,500 400 1,000 300 200 500 100 0 0 1975 1980 1985 1990 1995 2000 2005 1975 1980 1985 1990 1995 2000 2005 Water Year Water Year Maumee R. Bioavailable Phosphorus Loading Maumee River, Bioavailable Phosphorus Loads Bioavailabe Soluble Phos. Bioavailable Particulate Phos. 2000 Bioavailable Phosphorus 1600 Loads, metric tons 1200 Dissolved 30% bioavailable bioavailable 800 equals 400 110% of 0 DRP 1975 1980 1985 1990 1995 2000 2005 Water Year
- 20. Why has thedissolved phosphorus loading from the Sandusky and Maumee rivers dropped and then increased so much?
- 21. Figure 18. Analysisof Ohio commercial phosphorus fertilizer sales from 1955-2006. Source: Commercial Fertilizer Report, published by the Association of American Plant Control Officials
- 22. No-till and reduced-tillcan increase dissolved phosphorus runoff.
- 23. Soil Testing ForCrop For Environmental Production Runoff Environmental Soil Testing Agronomic 0-2 inches Soil Testing Soil Testing to 0- 8 inch Evaluate cores Stratification Soil 2- 8 inches Plants can generally Dissolved phosphorus access nutrients within concentrations are the top 8 inches of soil generally proportional to soil test P in top 2 inches
- 24. Critical Phosphorus SoilTest Concentrations for Corn and Soybeans Ohio State University Extension Fact Sheet, 2007, Watson & Mullen
- 25. Agronomic Soil Testing– 381 fields in the Sandusky Watershed
- 26. Sandusky DRP 90% of Sandusky Soil tests are in this range. As soil test phosphorus increases, dissolved phosphorus in runoff increases. The higher the soil test value, the more phosphorus farmers lose to runoff.
- 27. Phosphorus Stratification, Comparisonbetween top 2 inches of soil with 0-8 inch values, 381 fields in the Sandusky Watershed 200 180 Mehlich3-P, 0-2 inches, ppm 160 140 120 100 80 60 40 20 0 0 20 40 60 80 100 120 140 160 180 200 Mehlich3-P, 0-8 inches, ppm Phosphorus accumulates in the upper layer of soil under no-till and reduced-till cropping practices.
- 28. Sandusky Watershed, Comparisonof Agronomic and Environmental Soil Tests 0-2 0-8 inch 100 90 Agronomic Percentile of 381 fields 80 Soil Test 47 72 70 Environmental Soil Test 60 50 34 52 40 30 22 32 20 10 0 0 25 50 75 100 125 150 175 200 Mehlich 3 Phosphorus Soil Test Resuts, ppm
- 29. Crops in theSandusky Watershed: 2006 Cropland Corn Beans Wheat Hay Acres 758,630 248,430 406,210 97,980 3,670 Percent 32.7% 53.5% 12.9% 0.5% Very low erosion rates --- 1.9 tons per acre per year for cropland Most of the soils are classified prime farmland if drained (884,000 acres) and prime farmland ( 158,000) Not prime farmland – 117,000 acres
- 30. Average 453 kg/ha USGS Midwestern agricultural watershed Maumee (582 kg/ha) data base for Sparrow Model Sandusky (689 kg/ha) calibration Sandusky – higher than average suspended sediment export, even though low erosion rates. Cause: relatively high clay content of most cropland soils
- 31. Average = 0.851kg/ha Maumee (1.43 kg/ha) Sandusky (1.68 kg/ha) High total phosphorus loads in spite of 20 years of control programs to reduce phosphorus runoff.
- 32. Average = 25.48kg/ha Maumee (25.5 kg/ha) Sandusky ( 27.21 kg/ha) High nitrogen export in spite of low proportion of corn in cropland.
- 33. Value of nutrientslost in 2007 from Sandusky Watershed (as measured at Tindal Bridge and using 2008 fertilizer prices) Nitrate- nitrogen - $8,196,000 Organic nitrogen - $3,744,000 Particulate Phosphorus - $1,795,000 Dissolved Phosphorus - $602,500 Total - $14,337,500 ($17.88 per acre in watershed)
- 34. What strategy shouldbe used for programs to reduce dissolved phosphorus loading to Lake Erie from agricultural sources? High hanging fruit High cost per unit reduction Medium hanging fruit Medium cost per unit reduction Low hanging fruit Low cost per unit reduction
- 35. Should we focuson small Large watersheds, picking low, Watershed medium and high hanging fruit? Small Watershed 319 Project focus is often on small watersheds …. …supports assessment? Should we focus on low hanging fruit over large areas? Objective: Reduce phosphorus export Stream system from large watersheds to Lake Erie.
- 36. What are thelow hanging fruits relative to reducing dissolved phosphorus runoff? 1. Drawdown or no fertilizer applications on soils with agronomic soil test values above “maintenance range” 2. Soils with environmental soil test values above a “threshold value” (yet to be determined). 3. Minimize fall and winter broadcast applications of fertilizers. 4. Encourage deep banding and injection of fertilizers. 5. Improve soil tilth (water infiltration and water holding capacity) 6. Continue traditional soil conservation measures.
- 37.
- 39. How do youmeasure nonpoint source pollution? … the watershed approach for quantifying nonpoint pollution. Point source input Stream gaging/monitoring station watershed boundary Assumes 100% delivery of Total Watershed pollutant through Export the streams. Total Nonpoint source Point source loading = watershed - inputs output
- 40. The Heidelberg UniversityTributary Loading Program Sampling Stations Station Support ODNR Michigan DEQ Lake Erie CREP Great Lakes Protection Fund EDF/Joyce Foundation USDA/NRCS All stations are associated with USGS Stream Flow Stations
- 41. These observations ledto efforts to control agricultural phosphorus loading through erosion control efforts (no-till and reduced-till) to reduce particulate phosphorus.
- 42. The Maumee andSandusky Rivers make up about 62% of the land drainage to the 22.4 % of Western Basin. land area enters the connecting channels River Raisin 32.0 % of land area drains in to the central and eastern basins of Lake Erie 42.6 % of land area enters the western basin Maumee River Sandusky River