HANDLE WITH CARE:HANDLE WITH CARE:BIODEGRADABLE BIODEGRADABLE

MULCH HANDLING MULCH HANDLING AND CLEANING AND CLEANING

Jeremy S. CowanDepartment of Horticulture and Landscape Architecture, Washington

State University, WSU Mount Vernon NWREC, 16650 State Route 536, Mount Vernon, WA

98273

Mount Vernon, Washington field site, July 23, 2010

Evaluating Biodegradable Plastic Evaluating Biodegradable Plastic Mulches for Use in High Tunnel Mulches for Use in High Tunnel Tomato Production in Western Tomato Production in Western

WashingtonWashington Effects of BDM on tomato yield and fruit

quality oBrix, Acidity, pH, Firmness, *Ascorbic Acid,

*Lycopene

Visual ratings of BDM degradation and image analysis Calibrate visual assessments w/ image analysis and

compare with physical properties to determine efficacy for measuring loss of BDM integrity

Potential Barriers to Adoption Demonstration plots, field days, focus groups,

surveys

Crop Yield & Fruit Quality Assessments

Marketable fruit (USDA grading) for fresh tomato: average weight and total fruit count

Unmarketable fruit categorized by predominantdisorder or disease

Fruit quality assessments include: Juice content Soluble solids (Brix) pH & titratable acidity Lycopene and β-carotene Ascorbic acid

Table 1. Comparison of tomato yield in each field location (HT and OF) in Washington in 2010.

Table 2. Comparison of tomato yield by mulch treatment in Washington in 2010

Notice the tenting of SB PLA mulch and edge degradation of cellulose mulch at soil interface.

SB PLA

Cellulose

Table 3. Comparison of area under mulch degradation progress curve (AUDPC) values amongmulch treatments by field location (HT and OF) in Washington in 2010

Digital imaging of mulch samplesTransformation to monochromatic

imagesHistogram of luminosity is obtainedCompare area under histogram curves

of BDM samples at Times 1 – 3 with visual assessments and physical properties data to establish correlation coefficients

Image-based Analysis of BDM Degradation

BDM samples collected & analyzed upon receipt from manufacturer (Time 0), at mulch laying (Time 1), at first flower (Time 2), and at final harvest (Time 3)

Evaluating primary physical/structural characteristics by measuring: Thickness Weight Tensile strength Elongation Tearing strength

Mulch Treatment Degradation & Biodegradation Assessments

The QuestionIf biodegradable plastic mulches

provide both environmental benefits (no landfilling or burning) and

economic benefits (one study reports a 25% cost savings) then why are

farmers slow to adopt in the United States, specifically Western

Washington? And, how might an opportunity to see degrading mulches

affect growers perceptions?

Theoretical FrameworkNeoclassical Economic Theory

Diffusion of Innovations

Bourdieu’s Theory of CapitalForms of Cultural Capital

Epistemic Barriers

Current Status Year 1 complete Year 2

Tunnels are upBDM’s are laid Inside tomatoes planted

Protocols for image analysis being developed

Light box designed and under construction Experimental design for adoption study

under development Demonstration plots are being planned

Many Thanks to:Carol MilesKaren LeonasDebbie Inglis & Babette

GundersonJonathan Roozen, Karen

Hasenoehrl, and the MV Veg Hort Team and Grad Students

Hang Liu and the Leonas’ Lab