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April 2023

Catherine Carbajal

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Catherine Carbajal​�BApplSc, MEnvMgt,​

ISA Certified Arborist NZ-0212A​

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How to facilitate faster uptake / acceptance ​

of Vetiver Grass Technology (VGT)​

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Introduction

  • Chrysopogon zizanioides (vetiver) has numerous beneficial uses.
  • Personal research revealed impressive results in mitigating soil erosion, water pollution, coral reef destruction, soil contamination, agricultural challenges, and bush fire devastation.
  • Why is Vetiver Grass Technology (VGT) not universally embraced despite its effectiveness compared to costly and challenging alternatives?

Catherine Carbajal

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April 2023

Photo by PetPitcher

Photo by C Carbajal

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Background

  • Lack of scientific data initially, but progress is being made.
  • Farmers relied on anecdotal evidence and observed results.
  • Goal: Provide scientific data to convince bureaucrats and insurance companies.
  • Vetiver has a long history of use and gained global attention in the last century.
  • Challenges in convincing bureaucrats about vetiver's effectiveness.
  • VGT is sustainable, promotes biodiversity, and serves as a pioneer plant.

Catherine Carbajal

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April 2023

Photo by Peter Pitcher​​

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CHALLENGERS - WHO are they?

Major blocks

  • Conservationists
  • Bureaucrats
  • Insurance companies
  • Engineers

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Engineers sometimes face obstacles due to other 'major blocks'.  

The favoured approach on Waiheke Island: Soil nails combined with geotextiles. 

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Catherine Carbajal

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April 2023

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Soil nails and geotextile combined with VGT

Property with landslide, engineers' design with geotextiles, and later extended vetiver planting for stability.

Catherine Carbajal

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April 2023

Ollie Hawes marks out rows for vetiver

Failure of soil nails and geotextile

Photo by C Carbajal

Photo by C Carbajal​

Photo by C Carbajal​

Photo by C Carbajal​

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Catherine Carbajal

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April 2023

Vetiver growing around engineers' soil nails and geotextile

April 2023

Photo by C Carbajal​​​

Photo by C Carbajal​​​

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Threats

  • Conservationists - zealots with limited knowledge

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  • Bureaucrats - unknown agendas

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  • Insurance companies - quantified assurance

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  • Engineers - understand facts and data

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Catherine Carbajal

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April 2023

Auckland floods: Why storm caused so mahttps://www.nzherald.co.nz/nz/auckland-floods-why-storm-caused-so-many-landslides-and-what-can-be-done-about-it/QILCUPBV2BDWTF3VVLHG2N7ZGQ/ny landslides – and what can be done about it - NZ Herald

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LESS VISIBLE�CHALLENGES

  • Recklessness:   Attempts to change the sterile status of Chrysopogon zizanioides.
  • Greed and deceit:   There are those who are looking at the bottom line in money terms – not the best environmental and economic option.
  • Ignorance:   VGT cannot be learned by looking online, there must be a genuine understanding of its strengths and weaknesses before advising others.

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April 2023

“. . . at $5 slip you will get every

cowboy in Hawaii getting into 

the business, especially when

vetiver is the easiest plant in the world

to propagate in a nursery or the field. And do people know what they are actually buying from the cowboys, do they know what vetiver grass looks like? We should get into registering growers and contractors somehow for the Vetiver System, or they will plant it any way and give it a bad name.”

John Greenfield

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SHORTCUTS

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  • A client's desire to save money led to employing contractors unfamiliar with VGT.

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  • A shallow landslide occurred within two months.  The yellow line shows the shape of the top row of vetiver.

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Catherine Carbajal

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April 2023

"functional simplicity obscures the complexity of design​"

Photo by C Carbajal​

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ENVIRONMENTAL DESTRUCTION

  • Risks to farmers , forestry and rural areas
  •  VGT combined with native planting can prevent or mitigate these risks
  • Urban rain gardens using vetiver grass helps with stormwater
  • Poor stormwater designs lead to problems elsewhere
  • VGT can reduce damage caused  from flooding and slash

Catherine Carbajal

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April 2023

Photos by Steph Milligan

Dead sheep 

Scarred landscape

Forestry slash

Washed out bridge

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Catherine Carbajal

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April 2023

VETIVER THE PIONEER

•    Non-native concerns are a reason often given for not using VGT   

•   Vetiver is a pioneer plant that helps with native vegetation regeneration   •  Vetiver can regrow from dormant roots after bushfire

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Vetiver regrowth a few weeks

after fire

2008​

2000

Photo by Don Miller​

Photo by Don Miller​​

Photo by Don Miller​​

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SOME SOLUTIONS

  • List the merits of the plant
  • Embrace weaknesses in VGT
  • Back up claims with data
  • More nurseries
  • Educate

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Catherine Carbajal

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April 2023

Photo by C Carbajal​​

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STRATEGIES

        • Address each point
        • Be helpful
        • Be prepared for the tough questions
        • Be honest and gracious
        • Know your audience

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Catherine Carbajal

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April 2023

Photo by C Carbajal​​

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MY QUESTIONS

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  1. What happens to the root system of vetiver when it is shaded out?
      • Is it dormant or rotting?
      • How long is it viable?
      • What effect does dormancy have on tensile strength?

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Catherine Carbajal

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April 2023

?

?​

?​

?​

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2.   How can we measure root strength?

3.   How can we make VGT quantifiable to compare with engineers’ results?

Photo by C Carbajal​​​

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Catherine Carbajal

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April 2023

Thank You

Photo by C Carbajal​​​