Provide aesthetic and environmental advantages in urban environments

Science around the country has provided the best management practicesfor achieving both

Lawns and Landscapes

Transition imageProtecting Water Quality With Science-based Lawn and Landscape Management Practices

Hillsborough County Board Of County Commission Workshop, December 9, 2009

George Hochmuth and Terril NellUniversity of Florida, IFAS

Thank you for the invitation to present the science behindbest management practices that enhance water quality

The role of science in solving problems

Science answers questions

Science points to potential problems or un-intended consequences that need more research

Unintended consequencesWe have been presenting what our

Florida science 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 theseprocesses has allowed scientists to develop best management practices and educational programs to protect the water quality

What have scientists determined?

National StudiesAddressing similar water quality issues to

ours in FloridaStudying the same underlying biological and

physical science principlesAimed at developing solutions in the form of

BMPs Focus on education

OklahomaTurf inhibits runoff better than any other

surfaceManagement practices can be designed

to take greatest advantage of turf for protecting the environment

Problems occured when BMPs were not followed

WisconsinFactors of greatest importance to nutrient losses from lawnsDepth of runoffFailure to fertilize-reduced stand

Factors of lesser importanceDe-compacting the soilType of fertilizer

MichiganLabeled N-15 urea nitrogenLeachate recovery of N was 0.23% of

total applied over 2 years80% N recovered in soil, thatch, and

clippingsSuggested volatile losses of remainder

Guelph, Ontario, CanadaUptake 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 CarolinaNitrogen 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

periodRoot mass-100,000 roots and 1

million root hairs per liter of soil

New MexicoN leaching less than 1% of appliedN leaching related to photoperiodMore N leached when PP was < 12 hours

Slower growthN loses can be avoided by proper N

fertilization practices

TexasImpervious : pervious surfacesTurfgrass (fertilized) versus native

prairie grasses (unfertilized)Less runoff with more pervious surface

and with turf compared to native grasses

PennsylvaniaRunoff from turf on 9 to 13 % sloped

areasExcellent turf health and good quality

loam soil with high infiltration rateNitrate in runoff was not different from

concentration in the rain water

Georgia40 to 70% of rainfall exited plots as

runoffOnly 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 restorationeffort. Government must also be accountable for itsrestoration responsibilities and commitments, andscientific measures can be an accurate barometer ofprogress and drive action at all levels. While there aresignificant and robust information and data systemsalready in place, some gaps remain. Ensuring theChesapeake Bay watershed population is informedof the scientific basis and results of actions is animportant element in encouraging broad participationin 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 ResearchFederal Grants-USDA, EPA, NSF, and

othersState Agency Grants-FDEP, FDACSWater Management DistrictsLocal Government-Counties,

municipalities, utilitiesIndustry Grants-Turfgrass, sod, fertilizer,

allied industries

Water quality research in Florida

A FDEP-funded research project with turf cultivars, fertilization programs, and irrigation

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4/4 4/18 5/2 5/16 5/30 6/13 6/27 7/11 7/25 8/8 8/22 9/5 9/19 10/3 10/17 10/31

1 lb N 1.75 lb N

Tot

al N

itra

te, m

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Total N Leaching inEstablished Floratam St. Augustinegrass 2006

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Warm-season turfgrass growth over the year

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

Transition image

We thank you for the invitationto bring the science to the table