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Lawns and Landscapes. Provide aesthetic and environmental advantages in urban environments Science around the country has provided the best management practices for achieving both. Protecting Water Quality With Science-based Lawn and Landscape Management Practices
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Lawns and Landscapes Provide aesthetic and environmental advantages in urban environments Science around the country has provided the best management practices for achieving both
Protecting Water Quality With Science-based Lawn and Landscape Management Practices Hillsborough County Board Of County Commission Workshop, December 9, 2009 Transition image Thank you for the invitation to present the science behind best management practices that enhance water quality George Hochmuth and Terril Nell University of Florida, IFAS
The role of science in solving problems Science answers questions Science points to potential problems or un-intended consequences that need more research
Unintended consequences • We have been presenting what our Floridascience says about potential unintended consequences to water quality of actions not based on science • These publications (Unintended Consequences, FAQs, and FFL) have been made available to you previously • Research in Florida is clearly supported by publications in the national peer-reviewed journals
The Nitrogen Cycle Understanding these processes has allowed scientists to develop best management practices and educational programs to protect the water quality What have scientists determined?
National Studies • Addressing similar water quality issues to ours in Florida • Studying the same underlying biological and physical science principles • Aimed at developing solutions in the form of BMPs • Focus on education
Oklahoma • Turf inhibits runoff better than any other surface • Management practices can be designed to take greatest advantage of turf for protecting the environment • Problems occured when BMPs were not followed
Wisconsin • Factors of greatest importance to nutrient losses from lawns • Depth of runoff • Failure to fertilize-reduced stand • Factors of lesser importance • De-compacting the soil • Type of fertilizer
Michigan • Labeled N-15 urea nitrogen • Leachate recovery of N was 0.23% of total applied over 2 years • 80% N recovered in soil, thatch, and clippings • Suggested volatile losses of remainder
Guelph, Ontario, Canada • Uptake was related to top and root growth-more N removal associated with greater root and top growth • Another study-positive linear relationship between plant N uptake and total plant biomass-healthier plants took up more N • Negative linear relationship between plant N uptake and N leached-More N uptake=less N leached
North Carolina • Nitrogen uptake greatest in most active growing periods • < 10% N recovered in the soil after 3 days in growing period-summer • > 80% N recovered in soil in dormant period • Root mass-100,000 roots and 1 million root hairs per liter of soil
New Mexico • N leaching less than 1% of applied • N leaching related to photoperiod • More N leached when PP was < 12 hours • Slower growth • N loses can be avoided by proper N fertilization practices
Texas • Impervious : pervious surfaces • Turfgrass (fertilized) versus native prairie grasses (unfertilized) • Less runoff with more pervious surface and with turf compared to native grasses
Pennsylvania • Runoff from turf on 9 to 13 % sloped areas • Excellent turf health and good quality loam soil with high infiltration rate • Nitrate in runoff was not different from concentration in the rain water
Georgia • 40 to 70% of rainfall exited plots as runoff • Only 16% N was found in the runoff from actively growing turf, from the fertilization event 24 hours before the rain event. • 64% N was found in the runoff from dormant turf
Executive Order 13508 Draft Strategy for Protecting and Restoring the Chesapeake Bay-MarylandNovember 9, 2009 Science underpins the Chesapeake Bay restoration effort. Government must also be accountable for its restoration responsibilities and commitments, and scientific measures can be an accurate barometer of progress and drive action at all levels. While there are significant and robust information and data systems already in place, some gaps remain. Ensuring the Chesapeake Bay watershed population is informed of the scientific basis and results of actions is an important element in encouraging broad participation in restoring the Bay.
Scientifically proven benefits of turfgrass, in the national literature • Healthy turf minimizes runoff • Healthy turf prevents soil erosion • Healthy turf is efficient at absorbing nutrients-dense root system-more so than other plants • Less than 1% of applied N leaches in well managed turf (confirmed in many states) • Seasonal variation in nutrient uptake-environmental implications
Funding for Turf and Landscape Water Quality Research • Federal Grants-USDA, EPA, NSF, and others • State Agency Grants-FDEP, FDACS • Water Management Districts • Local Government-Counties, municipalities, utilities • Industry Grants-Turfgrass, sod, fertilizer, allied industries
Water quality research in Florida A FDEP-funded research project with turf cultivars, fertilization programs, and irrigation
Total N Leaching inEstablished Floratam St. Augustinegrass 2006 Total Nitrate, mg M-2
Conclusions, Based on the Science Turf plays an important role in reducing fertilizer runoff and leaching-leading to improved water quality Turf must be properly managed including fertilization Proper fertilization is a key to maximizing the environmental benefit of turf Potential for environmental harm is greater during periods of reduced growth or when BMPs are not followed
Our review of the literature clearly shows there is no science, anywhere, supporting the idea of improved water quality with a fertilizer blackout To the contrary, science shows a blackout may lead to increased runoff and leaching Proper fertilizer management is a year-round activity and can best be accomplished with science-based BMPs and education
We thank you for the invitation to bring the science to the table Transition image