Nitrates in Groundwater- Filtering Out the Facts. Bruce Montgomery

Transcription

1 Nitrates in Groundwater- Filtering Out the Facts MN Agriculture and Nitrates Forum July 25, 2012 Rochester, Minnesota Bruce Montgomery MN Department of Agriculture

2 Nitrogen Fertilizer Management Plan Review MDA is currently revising this Plan which has been in place since 1990; Plan provides direction on how the State should proceed when groundwater is adversely impacted by the use of nitrogen fertilizer; Committee is made up of agricultural organizations, state agencies, UM, county staff and environmental groups; Review and recommendations should be completed by early next year; Many of the materials discussed today have been presented and discussed

3 3 out of 4 Minnesotans get their drinking water from GROUNDWATER 26% 20% Groundwater- Private Groundwater- Public Surface-Public 54%

4 Mythbusters

5 Driving with your tailgate down increases gas mileage. TRUE or FALSE??

6 Driving with your tailgate down increases your gas mileage? Correct Answer---FALSE (BUSTED)

7 Nitrate contamination is widespread across Minnesota and rapidly getting worse TRUE or FALSE??

8 Complicating Factors

9 Important to note that well construction and placement has huge implications on most water quality parameters Young Water (Sand points, observation wells) Moderate to Old Oldest (Public water supply wells, high capacity irrigation)

10 Nitrates Tend to Stratify Near the Top of the Aquifer Data Source: Bill Schuh, North Dakota State Water Commission

11 Travel Times Can Vary Drastically on a Localized Scale

12 County Well Index Data Nitrates in Private Drinking Wells Based upon the County Well Index, (MDH), approximately 6% of all wells in the state exceed MCL; Most elevated conditions are found in the Central Sands region and Washington/Dakota Counties

13 Two Home Owner Nitrate Monitoring Networks have been Recently Established Networks have been designed to provide lowcost nitrate trend information; Private wells; Homeowner participation is the cornerstone of the design;

14 Nitrates in Private Drinking Wells in the Central Sands Home Owner Network Approach included 1,555 Minnesota families; This recent data (2011) suggests that about 5% > Health Standard (10 mg/l); Approx wells will be used for long-term trends

15 Nitrates in Central Sands Network MDA Observation Wells-Edge of Field This data strongly suggests that nitrate loading was appreciable in the 1990 s and may now be stabilizing.

16 Southeast Nitrate Monitoring Network Data Source: MDH

17 Southeast Nitrate Monitoring Network Data Source: MDH

18 MDA Monitoring Uses a Diverse Approach: Streams/Rivers Springs Wells Edge of Field

19 Upward NO 3 -N Trends in Surface Waters

20 Spring Monitoring in SE Minnesota What s Their Story? Trend Summary: ppm/year and statistically significant Data Source: John Hines, MDA Monitoring Unit

21 Spring Monitoring in SE Minnesota What s Their Story? If this trend continues, the median value would exceed the MCL in approximately 32 years (range years) Data Source: John Hines, MDA Monitoring Unit

22 Spring Monitoring in SE Minnesota What s Their Story? Trend Summary: 2-4 more years needed to do trend analysis Data Source: John Hines, MDA Monitoring Unit

23 Drinking Water Standard Data Source: MDA Monitoring Unit

24 Data Source: PCA website

25 Nitrates in Public Water Supplies Based upon MDH data, less that 1% of Minnesota s public water supplies exceed the MCL; Older Data Source: MDH Figure 10. Distribution of public water supply wells in the County Well Index with nitrate-n greater than 3 mg/l

26 Ag Communities Dealing with Elevated Nitrate Issues The number of communities currently dealing with elevated NO 3 N conditions is well established and contained. Data Source: MDH/MDA

27 Hastings Municipal Wells Nitrate Results Drinking Water Standard

28 What s at Stake for Community Water Suppliers Dealing with Nitrate Problems? Nitrate removal systems typically cost between $2-3 Million for upfront construction costs and also maintenance costs Costs of drilling new and/or deeper wells; Costs of blending multiple wells to achieve get acceptable water quality; Consumer costs are 2-6 times higher than non-impacted water supplies

29 Greenvale Twp Apple Valley Lakeville Burnsville Eagan Castle Rock Twp Nininger Twp Empire Twp West St. Paul South St. Paul Mendota Heights Sunfish Lake Miesville Greenvale Twp Apple Valley Lakeville Burnsville Eagan Castle Rock Twp Nininger Twp Empire Twp West St. Paul South St. Paul Mendota Heights Sunfish Lake Miesville Water Testing Service : Kriged Nitrate Results Dakota County Water Testing Service Nitrate Results (860 Results, Kriged) Dakota County Water Testing Service Nitrate Results (860 results, kriged)

30 Hastings Area Private Drinking Water Wells Comparative Results: Nitrate n ~ 140 wells 65% 55% 45% 51% 47% % 25% 23% 32% 26% 21% 15% 5% -5% Above Drinking Water Guideline (> 10 mg/l) Elevated (>3 and <= 10 mg/l) Background (Zero to <= 3 mg/l)

31 Nitrate contamination is widespread across Minnesota and rapidly getting worse.. TRUE or FALSE??

32 Nitrate contamination is widespread across Minnesota and rapidly getting worse.. TRUE or FALSE??

33 Crop Selection and their Historic Acreages Help Explain Nitrate Trends in Groundwater. TRUE or FALSE??

34 Crops with Low N Loss Leaching Potential Alfalfa and Clover Vegetated Pasture Native Prairie/CRP Plantings Perennial Crops

35 Alfalfa, Clovers, Orchard Grass, and Other Perennials Are Excellent Nitrogen Scavengers

36 One Key Irrigation Pivot Was Voluntarily Converted to Alfalfa from Alfalfa

37 Nitrate-N Conc (mg/l) below rooting zone Impact of Crop Types under Irrigated, Coarse- Textured Soils Perham SWPA Russet Soybeans Alturas Alfalfa Second Yr Burbanks Alfalfa /16/00 6/26/00 8/4/00 9/20/00 5/15/01 7/24/01 12/18/01 6/19/02 Sampling Dates 9/4/02 5/20/03 6/26/03 7/31/03 10/24/03 6/9/04 9/10/04

38 Millions of Acres The Last 90 Years.. Acreage Trends in Minnesota s Legume Crops (All Hay and Soybeans) Alfalfa, Soybean Clover, etc Hay Soybeans Year

39 Wheat Sugar Beets Crops with Medium N Loss Leaching Potential Soybeans Barley and Other Small Grains

40 Millions of Acres The Last 90 Years.. Acreage Trends for Minnesota s Major Nitrogen Demanding Crops 10 8 All Small Grain Crops Corn 6 4 Corn Small Grains Potatoes Sugarbeet Sunflower Edible Beans Year

41 Crops with High N Loss Leaching Potential Grain Corn Potatoes Silage Corn Edible Beans

42 Crop Crop Selection Type Has and Huge their Impacts Historic on Acreages Nitrate Leaching. Help Explain Nitrate TRUE Trends or in FALSE?? Groundwater. TRUE or FALSE??

43 Nitrogen inputs on AG lands dwarf all the other sources.. TRUE or FALSE??

44 Most Recent Nitrogen Budget Analysis on Inputs to Land (not water) Septics 0% Sludge 0% Atmos(non-ag) 4% Non-Ag Lawn Fert 0% Atmos (AG) 4% Manure 8% Mineralization 14% AG Land Min 32% Legumes 12% N Fertilizer (AG) 26% Data Source: Wall, PCA

45 82% of Minnesota s Nitrogen Inputs are linked to Agricultural Land Manageable Minimal Control Minimal Control

46 We Have Direct Management Control Over About 55% of the N Inputs 10% 5% 0% 14% 40% Mineralization N Fertilizer (AG) Legumes Manure Atmos (AG) Sludge 31%

47 Nitrogen inputs on AG lands dwarf all the other sources.. TRUE or FALSE??

48 Nitrate losses would not be a problem if farmers stopped putting on nitrogen fertilizer. TRUE or FALSE??

49

50 Nitrate-N Loss in Lb/A/Year Mineralization Estimated Fertilizer Loss Partitioning Nitrate-N Losses from Mineralization and Fertilizer Applications (SROC Waseca, Wetter than normal years) Zero N 80 Lbs 120 Lbs 160 Lbs Data Source: Randall and Vetch, SROC Estimated Check using 10 ml/l, 9.3 inches of drainage which is one inch higher due to poorer water use efficiency)

51 Nitrate losses would not be a problem if farmers stopped putting on nitrogen fertilizer. TRUE or FALSE??

52 Nitrate contributions from Golf Courses and Lawns are excessive. True or False???

53 Perham Golf Course Demonstration Project

54 Parts Per Million Perham Golf Course Nitrate-N Levels Below the Fairways Lake Side Country Course at Perham Demonstration Project /21 8/3 8/18 9/7 11/14 5/24/2001 6/20 7/24 8/23 9/25 4/29/2002 6/11 7/5 8/25 9/20 5/20/2003 6/18 7/31 Sampling Dates

55 Nitrate-N (mg/l) Nitrate-N Concentrations under Traditional Irrigated Cropping Rotation vs. Golf Course Perham Wellhead Protection Area Due to the dense fibrous root system, coupled with following recommended rates, turfgrass 60 contributions are generally low to very low 5/11/2000 6/1/2000 6/26/2000 7/21/2000 8/11/2000 9/8/ /18/2000 5/15/2001 6/20/2001 Sample Dates 8/9/2001 9/26/2001 5/9/2001 6/19/2002 8/6/2002 9/20/2002 Nitrogen-PPM Golf All (Approximately) Golf 323 Samples Irrigated Ag 1200 Samples

56 Nitrate-N (mg/l) Nitrate-N Concentrations under Traditional Irrigated Cropping Rotation vs. Golf Course Perham Wellhead Protection Area /11/2000 6/1/2000 6/26/2000 7/21/2000 8/11/2000 9/8/ /18/2000 5/15/2001 6/20/2001 Sample Dates 8/9/2001 9/26/2001 5/9/2001 6/19/2002 8/6/2002 9/20/2002 Nitrogen-PPM Golf All (Approximately) Golf 323 Samples Irrigated Ag 1200 Samples

57 Nitrogen fertilizer sales have sky-rocketed to support the record corn production. TRUE or FALSE??

58 Short Tons of Material In Millions Trends in Total Fertilizer Tonnage Sold in Minnesota

59 Tons of Actual N Commercial Nitrogen Fertilizer Sales Trends in Minnesota: , , , , , , , ,000 Data Source: MDA, TVA, and AAPFCO Sales Since 1989 Ten Year Averages : 654, : 653,481

60 1,400 1,200 Relationship between Grain Corn Production, Acreage, and N Fertilizer Inputs Bushels Produced 1,000 Planted Acres N Fertilizer Inputs (estimated for corn) Corn Acres (X10000) Est. Tons of N Fertilizer on Corn (X1,000) Bu. Produced (Millions)

61 Ratio of Bushels Produced per Lb N Fertilizer Input Bushels of Corn Produced per Lb of N Fertilizer 1992 to Statewide "NUE" on Corn Using the N Balance Method

62 2012 Drought Impacts on N Recovery and Feed Quality? July12,2012 D0 Abnormally Dry D1 Drought - Moderate D2 Drought - Severe D3 Drought - Extreme D4 Drought - Exceptional GH PV WC HW CC KG WW RC BC

63 Nitrogen fertilizer sales have sky-rocketed to support the record corn production. TRUE or FALSE??

64 Producers are pouring on the fertilizer with no consideration of timing, sources, and rates TRUE or FALSE??

65 Characterizing Regional and Statewide Fertilizer Practices

66 NASS Corn Grower N Survey-2010 Statewide N Fertilizer Rates on Non-Manured Corn (Represents 17% of the fields surveyed) N /Acre Corn 143 Lbs/A Acceptable Range 120 to 165 (0.10 Value Ratio) Acceptable Range 120 to 165 (0.10 Value Ratio) Bierman et al., 2011

67 NASS Corn Grower N Survey-2010 Statewide N Fertilizer Rates on Non-Manured Corn (75% of the fields surveyed followed beans) N /Acre Soybeans 140 lb/acre Acceptable Range 90 to 125 (0.10 Value Ratio) Bierman et al., 2011 Acceptable Range 90 to 125 (0.10 Value Ratio)

68 NASS Corn Grower N Survey-2010 Timing of the Major N Source on Corn

69 Producers are are pouring pouring on the on the fertilizer fertilizer with no consideration TRUE of timing, or FALSE?? sources, and rates TRUE or FALSE??

70 Producers are are pouring pouring on the on the fertilizer fertilizer with no consideration TRUE of timing, or FALSE?? sources, and rates TRUE or FALSE??

71 Minnesota producers don t care about the environment and are unwilling to be part of the solution. TRUE or FALSE??

72 Some Examples of Successful Innovations Within Wellhead Protection Areas Introducing Alternative Cropping Systems (Park Rapids, Perham, St. Peter); Introducing N Efficient Potato Varieties (Perham and Park Rapids); Introducing ESN, N-Serve, and other slow release products (Cold Spring, Perham, St. Peter, Park Rapids, Verndale, etc); Land Swapping with City (Perham); Accelerated EQIP and CRP Signed Ups (Holland); Bioreactors (St. Peter)

73 Discovery Farms Minnesota Discovery Farms Minnesota is a farmer-led initiative to gather information and assess the water quality impacts of different types of farms, in landscapes all across Minnesota

74 Root River Field to Stream Partnership Water Monitoring