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Phone: +1.678.367.0981
Fax: +1.240.547.1795

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International Society of Arboriculture
PO Box 191
Annapolis Junction, MD 20701
United States

Physical Address

International Society of Arboriculture
270 Peachtree St NW, Suite 1900
Atlanta, GA 30303
United States

Order Delays Due to Physical Inventory

Due to ISA's annual physical inventory, orders placed between
2 p.m. EDT, Thursday, 20 June 2019, and 11:59 p.m. EDT, Friday 28 June 2019, will not ship until the week of 1 July 2019

Please plan your ordering accordingly.

We will resume regular turnaround times
1 July 2019.

Thank your for your patience.

Questions? Please call the customer service team at (678) 367-0981.

    Climbers' CornerTree Academy

    Determining Nutrient Leaching From Ornamental Landscapes for the Development of Landscape Fertilizer BMPs


    Determining Nutrient Leaching From Ornamental Landscapes for the Development of Landscape Fertilizer BMPs

    By    Gitta Hasing , Andrew K. Koeser , Drew C. McLean
    Environmental Horticulture Department
    Gulf Coast REC
     Institute of Food and Agricultural Sciences, University of Florida

    Amy L. Shober
    Nutrient Management and Environmental Quality
    Department of Plant and Soil Sciences
    University of Delaware  

    The current ANSI A300 fertilization standards and ISA fertilization best management practices (BMPs) offer industry-accepted guidelines for application rates, timing, and method. These recommendations are based on a limited body of research where tree growth and appearance were typically the primary, or only, responses assessed. Few, if any studies have looked at how woody ornamental fertilizer recommendations impact the surrounding environment. For this project, large-volume lysimeters were used to track N use efficiency and leaching from shrub installation through the first year of establishment. Sweet viburnum (Viburnum odoratissimum) shrubs grown in 3.78-L (1-gallon) containers were planted into each lysimeter and fertilized every 12 weeks with slow release polymer coated urea to maintain annual N rates of 0, 98, 196, and 293 kg ha-1 (0, 2, 4, and 6 lb N per 1000 ft2). Fertilizer was applied per plant or broadcast across the surface of the entire lysimeter to evaluate the effect of application method on nutrient leaching. Scheduling of fertilization was assessed with and without a locally-enforced summer blackout period. Preliminary data analysis shows significant differences in NO3+NO2-N loading in leachate given the various fertilization regimes tested. Nitrate loads varied by rate (P<0.0001), method of application (P<0.0001), schedule [i.e., regular or blackout (P<0.0001)], the interaction between rate and method (P=0.0017), the interaction between rate and schedule (P<0.0001), the interaction between method and schedule (P<0.0001), and the three-way interaction between all main effects (P=0.0055).  Results shows that increasing the intensity of various main effects generally had a compounding effect of nitrate loads. Implications for ongoing and future management BMPs are discussed.


    Gitta Hasing is a Biological Scientist in the Environmental Horticulture Department at the University of Florida. Gitta is an ISA certified arborist and works in an urban landscape management lab at the Gulf Coast Research and Education Center near Tampa, Florida. She earned a Master’s degree in Environmental Horticulture from the University of Florida while working as a Biological Scientist from 2006-2013 in the University’s Soil and Water Science Department. Gitta received her undergraduate degree from the University of Delaware in 2005.

    Andrew K. Koeser  is a Professor of Landscape Management at the University of Florida-Gulf Coast Research and Education Center near Tampa, Florida (United States) and an International Society of Arboriculture (ISA) Board Certified Master Arborist. Prior to working at the University of Florida, Andrew worked for five years at the ISA headquarters in Champaign, IL (United States) – starting as an intern and advancing to Science and Research Manager. He holds a Ph.D in Crop Sciences (Horticulture and Biometry emphases) from the University of Illinois at Urbana-Champaign, a M.S. in Natural Resources and Environmental Sciences from the University of Illinois at Urbana-Champaign, and a B.S. in Forestry (Urban Forestry Emphasis) from the University of Wisconsin – Stevens Point.

    Climbers' CornerTree Academy

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