Natural Resources & Environmental Stewardship Fundamentals of Nutrient Management Melissa L. Wilson Department of Environmental Science & Technology Ag Nutrient Management Program University of Maryland, College Park Photo credit: Ben Fertig, Integration and Application Network, University of Maryland Center for Environmental Science
Plan for this segment Water pollution and the hydrologic cycle Unique challenges in the Chesapeake Bay region Farm nutrient balance Best Management Practices (BMPs)
Do any of your personal actions result in the pollution of our waters? A. Yes B. No
Modern life leads to soil-water pollution Intensive crop and animal production nutrients, sediments, pathogens, pharmaceuticals Growth of towns and cities sediments, nutrients, pharmaceuticals, PCBs Transport of people and goods hydrocarbons, fuel additives, NO x, metals Manufacture of consumer and industrial goods solvents, metals
Water quality impairment is widespread in the U.S. Streams/Rivers Lakes/Ponds Estuaries/Bays 55% 45% 71% 29% 83% 17% 1,123,830 miles assessed 18,314,165 acres assessed 56,420 sq. miles assessed Good Impaired Information from: EPA. 2017. https://ofmpub.epa.gov/waters10/attains_nation_cy.control#stream/creek/river
What are the impairments? Agricultural activities are responsible for half of the impaired rivers, streams, and lakes nationwide. Information from: EPA. 2000. https://www.epa.gov/sites/production/files/2015-09/documents/2000_06_30_305b_98report_98summary.pdf
Lake Erie, Sept. 3, 2011 Illustration from: Nat. Geo. 2013. http://voices.nationalgeographic.com/2013/04/24/harmful-algae-blooms-plague-lake-erie-again/
Aug. 2009 at Norfolk, VA. Photo credit: Ryan C. Hendrickson (pilot)
Types of Pollution Point source source is easily identified; control is straightforward; end of pipe Wastewater treatment plants Confined Animal Feeding Operations Nonpoint (diffuse) source arises over landscapes from various land uses; occurs during and after rainfall cropland and pasture land towns and cities
What types of pollution are important for nutrients? A. Point Sources B. Non-point sources C. Both of the above D. None of the above
The Water Cycle Illinois State Water Survey
Inches of water 10 8 6 4 2 0 Soil-Hydro. Cycle, Lower Eastern Shore Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ppt PET Soil Drainage Meisinger
In what season is the risk of nutrient loss due to runoff the highest? A. Spring (Apr June) B. Summer (July-Aug) C. Fall (Sep Nov) D. Winter (Dec-Mar)
Seasonal changes in N concentration Nitrate concentrations in the Pocomoke River, 1999-2000 Diagram from: USGS 2015. https://pubs.usgs.gov/circ/1406/pdf/circ1406.pdf
Sources & Transport Sources Transport N-P-K Leaching Tile flow Subsurface flow Modified from Sharpley & Gburek, USDA-ARS
N & P from a water quality perspective Nitrogen (as nitrate) is lost to leaching contaminates ground water Surface waters are contaminated during ground water discharge Phosphorus soluble P is lost in runoff sediment-bound P is lost during erosion P losses are surface water issues
N & P from a water quality perspective Nitrogen (as nitrate) Phosphorus Diagrams from: Amy Shober, UDEL. 2013. http://extension.udel.edu/factsheets/the-impacts-of-nitrogen-and-phosphorus-from-agriculture-on-delawares-water-quality/
The Water Cycle Illinois State Water Survey Baseflow & stormflow are important!
6 Nitrogen at Watershed Outlet 5 4.9 4.7 Nitrogen (ppm) 4 3 2 1 1.7 0.5 0.7 2.4 1 3.3 0 forest pasture cropland mixed Baseflow Stormflow Land Use
The process of nutrient over-enrichment of a body of water is called: A. Phosphorication B. Eutrophication C. Nitrification D. Hypoxia
Nutrient Pollution: Grand Challenge of the 21 st Century Healthy Eutrophic
The Chesapeake Bay Watershed Bay area: 4,480 mi 2 (the largest estuary in the U.S.) Average depth: 21 ft Basin area: 64,000 mi 2 Ratio of watershed area to bay area: 14:1 19 major rivers flow into the bay Basin is in 6 states and the District of Columbia Population: 17+ million (in 2010) Value of fisheries harvest: $2,000,000,000 per year! Major pollutants: nutrients (N and P)
Ratio of watershed land area to water volume Chesapeake Bay Gulf of Finland Arabian (Persian) Gulf Baltic Sea Great Lakes Sea of Cortez 0 500 1000 1500 2000 2500 Land area/water volume (km 2 /km 3 ) Reproduced from Ann Swanson. 2011. Congressional Briefing: The Chesapeake Bay Commission.
Thin, rocky soils with range soil textures. Some areas of limestone and karst exist. Thin soils (usually less than 3 ft deep), more clay than the Coastal Plain Thicker soils with more sand than other areas of the state
How quickly water moves through the soil depends on the soil texture Sand Silt Clay
Coastal Plains Both Ridge and Valley And Piedmont karst -highly weathered limestone
Information from: Chesapeake Bay Program. 2009. http://www.chesapeakebay.net/blog/post/question_of_the_week_what_are_the_main_sources_of_pollution_to_the_bay
Fall 2016, CBF, Save the Bay Magazine Information from: Chesapeake Bay Foundation. 2016. http://www.cbf.org/news-media/features-publications/save-the-bay-magazine/fall-2016.html
June 2015, CBF, Save the Bay Magazine
What is a nutrient balance with respect to farms? A. N and P inputs should equal crop uptake B. Carefully measuring and documenting nutrient applications on fields C. Inputs of nutrients to the farm should equal the nutrients removed D. Ensuring N and P rates are balanced
¼ Crop s Soil Local Animals ¾ Manure
¼ Feed mill Crops Soil Global Animals ¾ Manure???
How can ag-related N and P pollution be minimized? Apply manure and N fertilizers at the appropriate rate and the proper time Avoid manure usage on P-enriched soils near streams and rivers
Yield Response Yield, % Maximum 100 90 80 70 60 50 2.5% yield increase 16% yield increase 40 lbs N 40 lbs N 40 0 50 100 150 200 250 300 350 400 Nitrogen Pounds Per Acre
Corn Yield and Valuable End-ofseason Nitrate in Maryland 200 Grain Yield, bu/ac or Soil NO3-N lbs N/ac 160 120 80 40 0 0 50 100 150 200 250 300 Fert. N, lbs N/ac Corn Grain Yield Fall Soil NO3 0-3 ft
2015, CBF, Save the Bay Magazine
Which of the following farm field scenarios would be considered environmentally sensitive and could benefit from the use of cover crops? A. Karst underlying a field B. Coarse-textured soils (high sand content) C. High soil-p (FIV-P >150) D. All of the above
Questions? Photo credit: Ben Fertig, Integration and Application Network, University of Maryland Center for Environmental Science