session fri-a06 organic landscape management€¦ · architecture from north carolina state...

Session FRI-A06: Organic Landscape Management—Perceptions vs. Reality 1

Organic Landscape ManagementPerceptions vs. Reality

OVERVIEW

Landscape architects often take maintenance of our designs for granted. Now, global environmental awareness is yielding numerous organic approaches to landscape management. Which are most effective—and least?

How can we educate clients to adopt these methods? This expert panel will present the latest scientific findings and provide practical recommendations.

1. This session will discuss the public perception that organic landscape management practices are always preferable and more sustainable than traditional approaches—which is not necessarily true. Scenarios will be presented of a landscape which is designed, built and maintained utilizing organic management strategies.

2. The focus of this educational session will be to evaluate various organic approaches from a scientific perspective.

3. The discussion will be grounded in peer-reviewed, scientific literature so that conjecture does not cloud the issues

4. To be effective practitioners, landscape architects need to be knowledgeable of what scientific data are available to assist them in decision-making when choosing soils, plant material, cultural/planting practices and providing advice to owners about maintenance/management options

Session FRI-A06


PANELISTS

BRYANT SCHARENBROCH, PHD UNIVERSITY OF WISCONSIN | MORTON ARBORETUM

MIKE RAUPP, PHD PROFESSOR OF ENTIMOLOGY | UNIVERSITY OF MARYLAND

KELBY FITE, PHD BARTLETT TREE RESEARCH LABORATORIES

ROBERT UHLIG ASLA LEED AP BD+C HALVORSON DESIGN PARTNERSHIP

Bob, a Principal at Halvorson Design Partnership, Inc. in Boston, MA, has guided design and implementation on significant urban projects that integrate site design and ecological systems, including: South Boston Maritime Park, Center City Park in Greensboro, North Carolina, Atlantic Wharf, and the Boston Architectural College Green Alley Initiative. He holds a Bachelor of Environmental Design in Landscape Architecture from North Carolina State University.

Bryant Scharenbroch is Assistant Professor, Soil Science at University of Wisconsin, Stevens Point and Research Fellow at the Morton Arboretum. Bryant has a Ph.D. in Soil Science from the University of Wisconsin, Madison; an M.S. in Plant Science, from the University of Idaho; and B.S. in Urban Forestry and Forest Management from the University of Wisconsin, Stevens Point. Bryant is an Associate Editor for Arboriculture and Urban Forestry. He chairs the Urban and Anthropogenic Soils Division of Soil Science Society of America and the Urban Tree Growth & Longevity Working Group of the International Society of Arboriculture. Bryant received the ISA’s 2013 Early Career Scientist Award.

Mike is a professor at the University of Maryland. He provides training on the theory and practice of IPM to arborists and landscape managers. With more than 200 publications and 1000 presentations on the ecology and management of arthropod pests, he is an international expert. He is a regular guest on television and radio and has received several awards including the Secretary of Agriculture’s Award for Environmental Protection and the ISA’s Richard Harris Authors Award. His most recent book, Managing Insects and Mites of Woody Plants: An IPM Approach is an authoritative guide to IPM and PHC.

Kelby has been a member of the Bartlett Tree Research Laboratories team for thirteen years, beginning as a Plant Protection Specialist and Diagnostic Lab Manager. Currently as an Arboricultural Researcher, his main responsibility is research and education in shade tree management and arboriculture, with emphasis on urban soils and integrated pest management. He holds a Ph.D. in Plant and Environmental Science from Clemson University, with a research focus on urban soil renovation and root biology. He also holds a Master of Plant Protection and Pest Management, and a Bachelor of Science in Horticulture, both from the University of Georgia.


PRESENTATION OUTLINE 1. Panelist Introductions

2. Organic Soil Management

3. Organic Pest Management

4. Cultural Landscape Practices and Landscape Management

5. Landscape Architectural Takeaways

6. Question and Answer

LEARNING OBJECTIVES • Understand nuances of using organic versus traditional treatment strategies in landscapes

• Compare efficacy of treatment options to benchmark performance expectations

• Examine ecological and financial site impacts to determine prudent design and management approaches

• Gain insight into how landscape design elements and installation quality impact management strategies


Bryant Scharenbroch, PHD University of Wisconsin | Morton Arboretum

1. What is soil fertility?• The quality of a soil that enables it to provide nutrients in adequate

amounts and in proper balance for the growth of specified plants or crops (Soil Science Society of America)

2. Is soil fertility important for urban trees?• It is when it is a limiting factor• Many other limitations are also present for urban trees• Soil fertility is often the focus of our attention and management, but it

may be that soil physical conditions are limiting trees• Soil and/or plant testing must be performed to identify nutrient

deficiency• Certain circumstances on conditions may serve as clues that fertility is

limiting to trees, such as when organic matter levels are low or soil pH is >8 or <5

3. Approaches for managing soil fertility with pros and cons• Inorganic fertilization

> Pros: immediate response and improves soil fertility >Cons: potential environmental impacts and costly

• Organic fertilization Solid materials -Wood chips >Pros: improves soil quality and very slow nutrient release (might also be a con) >Cons: aesthetics -Compost >Pros: improves soil fertility, improves soil quality and slow nutrient release >Cons: aesthetics (this should not be a concern) -Biochar >Pros: improves soil quality and reduces waste >Cons: limited availability -Biosolids >Pros: improves soil fertility and reduces waste >Cons: potential environmental impacts and social stigma Liquid materials -Biostimulants >Pros: adding water >Cons: ineffective and costly -Compost tea >Pros: adding water and some K >Cons: ineffective and costly

Cost-benefit analysis for different approaches for managing soil fertility


Mike Raupp, PHD Professor of Entimology | University of Maryland

1. What does organic mean?Organic Foods Production Act of 1990 – Crops must be: • Grown on land that has been free of prohibited pesticides and

substances for at least three years before harvest• Consistent careful management of soil fertility• Correct dispersal of manure• Use prevention as the first form of pest control• Must have buffer zones that protect from the flow of unwanted

substances from nearby farms

2. What is the National Organic Program (NOP)• Regulatory program housed within the USDA Agricultural Marketing

Service• Develop national standards for organically-produced agricultural

products• Assure consumers that products with the USDA organic seal meet

consistent, uniform standards

3. How does organic landscape management relate to Integrated Pest Management (IPM)?

IPM is the selection, integration, and implementation of pest control based on economic, ecological, and sociological consequences (Davidson and Raupp 2014).

4. What control tactics are used in IPM programs for landscape plants?Examples of IPM tactics for key tree pests – a. Evergreen Bagworm, native, generalist

• Cultural Controls – Avoid monocultures of evergreens, high rates of fertilization

• Resistant Varieties – Deciduous trees are more resistant than evergreens

• Mechanical control – Hand removal of bags in winter• Biological Control – Formulated microbials - entomopathogenic

nematodes• Chemical Control – OMRI listed, organic insecticides – spinosad, Bt

b. Emerald Ash Borer, non-native, specialist• Cultural Controls – Increase plant diversity, install and maintain trees

to minimize stress• Mechanical control – Basal pruning• Resistant Varieties – Ash trees of Asian origin, white ash, blue ash • Biological Control – Releases of parasitic wasps• Chemical Control – Tree injections with OMRI listed insecticides -

azadirachtin • Regulatory Control – Inspections, quarantine, eradication


5. What are OMRI listed insecticides? Organic Materials Review Institute (OMRI), a nonprofit organization founded in 1997

• Provides organic growers, manufacturers, and suppliers an independent review of products intended for use in certified organic production, handling, and processing

• Acceptable products are OMRI Listed® and appear on the OMRI Products List© or OMRI Canada Products List©

• OMRI lists 184 insecticides for a wide variety of pests including those in landscapes

6. Resources used for presentationManaging Insects and Mites on Woody Plants: An IPM ApproachJohn Davidson and Michael Raupp, Tree Care Industryhttps://secure.tcia.org/Core/Orders/product.aspx?prodId=700&catId=9 USDA National Organic Pesticide Programhttp://www.ams.usda.gov/about-ams/programs-offices/national- organic-program

OMRI Approved Insecticideshttp://www.omri.org/simple-opl-search/results/insecticide

7. Acknowledgements ISA Tree Fund, USDA NRI (2005-35303-16269) & SCRI (2011-51181-30937), McIntire Stennis Project MD-ENTM-0416 & 8732).

Mike Raupp, PHD Professor of Entimology | University of Maryland (cont.)


The Relationship between Cultural Landscape Practices and Landscape ManagementThe cultural aspects of landscape management can have a profound impact on the ability to use organic tools in the suppression of pests and improvement of soils. Poor cultural practices create environments that are unfavorable for plant growth, while more favorable for pest outbreaks. Many of these poor cultural practices result in the need to intervene with chemical control measures. When an organic program is preferred, there are often no OMRI approved options available. If landscape managers intend to use only organic tactics to manage the landscape, they must ensure that sound horticultural practices are in place. Plants can protect themselves through physical and chemical mechanisms in response to stimuli, such as insect feeding or fungal infections, and these plant defense mechanisms can be enhanced by reducing stresses on plants from improper cultural practices.

Sound horticultural design and good cultural practices will reduce the need to intervene with conventional or organic chemical control. The disease triangle (see below) is a concept that demonstrates that successful plant disease relies on three major parameters: a susceptible host, a virulent pathogen and a conducive environment. Through good cultural practices, disease can be reduced by creating an environment that is unfavorable for the pathogen, creating an environment favorable for the host, or planting a resistant variety, to name a few.

For example, fungal leafspot diseases require certain hours of leaf wetness before they can actively penetrate the leaf tissue resulting in a successful infection. Good cultural practices that can reduce fungal leaf spot diseases can include: • changing irrigation from above-ground to surface applications, which

reduces the duration of leaf wetness• pruning to thin the canopy, which allows more light and air penetration to

the foliage promoting leaf dryinguse of a resistant cultivar or species to achieve the same aesthetic goal

Similar examples can be made for other disease and insect pests. The use of cultural control tactics that promote plant health can often preclude the use of any chemical inputs; organic or conventional. This not only relates to biological pests, but also to soil management programs as well.

Kelby Fite, PhD Bartlett Tree Research Laboratories

session fri-a06 organic landscape management€¦ · architecture from north carolina state...

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