Post on 28-Dec-2015
Season Extension and Weed Management: High Tunnels and Biodegradable Mulches
Carol Miles, Vegetable SpecialistJeremy Cowan, Ph.D. Student
Department of HorticultureWSU Mount Vernon NWREC
Biodegradable Mulches for Specialty Crops Produced Under Protective Covers
Debra Inglis and Carol Miles (Project Directors)1;Andrew Corbin, Jessica Goldberger, Karen Leonas, Tom Marsh and Tom Walters1;
Doug Hayes, Jaehoon Lee, Larry Wadsworth and Annette Wszelaki2; Jennifer Moore-Kucera3; Russ Wallace4; Marion Brodhagen5 ; and Eric Belasco6;
1 25
SCRI Grant Award
No. 2009-51181-05897
43 6
SCRI Project Goals for High Tunnels
Assess agricultural and economic impacts of using high tunnels as compared to open field for tomato, lettuce and strawberry production
Compare performance of biodegradable mulch (BDM) in high tunnel and open field
Compare high tunnel structures in three diverse locations in the U.S. with focus on wind tolerance and labor requirements
Nanjing Agricultural University, Nov 11
DefinitionsDegradeMeasurable conversion of C to CO2 through abiotic factors such as heat, UV light, or mechanical stress.
BiodegradeBreak down via microbial activity; ultimately the oxidation of the parent compound to carbon dioxide and water, providing carbon and energy for the growth and reproduction of cells.
DeteriorateLoss of physical or mechanical strength as observed through physical testing, microscopic imaging or visual assessment.
Field Experiments Variety trials: 6 cvs tomato; 6 cvs lettuce; 6 cvs strawberryBDM trial: with tomato cv. CelebrityLocations: Mount Vernon WA, Lubbock TX, Knoxville TN
Experimental design:• Randomized complete block with four replications • Main plot: high tunnel and open field• Subplots: 3 feet wide bed, 14 feet long• BDM planted with tomato • Plots managed organically
BDM experimental treatments: 1) Experimental fabric – SB-PLA2) BioBag – starch-based (Mater-bi®) film3) BioTelo – starch-based (Mater-bi®) film4) Sunshine paper – cellulose, 100% degradable 5) Standard black plastic – PE, 1.0 mil embossed6) Bare ground / non-mulch control
High tunnels provide: • Increased heat • Protection from rainfall• Reduced leaf wetness • Increased crop yield • Shortened time to harvest for many crops
Mount Vernon, WA Lubbock. TX Knoxville, TN
Mount Vernon, WA Lubbock, TX Knoxville, TN
HT OF HT OF HT OF
GDDy (base 10 oC) 1007 740 1799 1661 1795 1463
Ave. daily max. air temp. (oC) 24.2 21.1 31.9 32.6 34.2 33.5
Ave. daily min. air temp. (oC) 10.5 9.7 24.7 18.9 17.5 18.7
Ave. soil temp at 5 cm depth
BioBag 18.9 17.7 26.2 25.6 26.2 27
BioTelo 19.3 18.1 25.9 26.6 27 26.8
SB-PLA-10 18.7 17 24.9 24.6 26.5 26.6
Weed Guard Plus 18.3 16.7 26.9 26.6 25.7 26.3
Black Plastic 19.8 18.9 27.2 28.2 27.8 27.3
Bare Ground 18.7 16.8 24.9 25.2 26.9 26.7
Ave. sol. rad. (µmol·m-2·s-1) 0.36 0.44 0.35 0.54 0.41 0.57
Relative Humidity (%) 79.7 81.3 66.2 66.7 74.1 79.2
Ave. wind speed (km·h-1) 1.1 3.3 0.2 6.4 0 1.9
Total rainfall (mm) 0 235.5 NA 333.5 0 156
Climate Comparison for HT and OF - 2010
Tomato Yield High Tunnel and Open Field at Mount Vernon 2011
Total Number (plot-1) Total Weight (kg.plot-1)
Lettuce Yield High Tunnel and Open Field at Mount Vernon in 2011
Total Weight (kg.plot-1) Marketable Weight (kg.plot-1)
Plastic mulch provides: • Weed control • Conservation of soil moisture • Increased crop yield • Modified soil temperature• Shortened time to harvest for many crops
Plastic mulch must be removed from the field for disposal; in-field incorporation and
biodegradation would eliminate disposal costs
Rick Boydston, USDA ARS
Biodegradable mulch generally made from:• Poly(lactic) acid (PLA)
- plant-based polyester produced from starch
• Polyhydroxyalkanoates (PHA)-polyesters produced by bacterial fermentation of sugar or lipids
Skeletal formula of poly(lactic) acid Bacillus subtilis poly-(R)-3-hydroxybutyrate
Andrew Corbin, WSU Extension
Presumed Mulch (Bio)Degradation
Doug Hayes, UTK
SCRI Project Goals for Biodegradable Mulches
Assess agricultural, ecological, and economic consequences of using biodegradable mulches in high tunnels and open field
Test PLA-based spunbond as mulch prototype
Compare PLA and commercial “biodegradable” mulches for performance in growing tomatoes
Provide data that may be useful for developing an ASTM standard for biodegradation of mulches in soil
Nanjing Agricultural University, Nov 11
CollaboratorsNature Works (U.S.), Saxon Textile Research Institute (Germany), and GreenBio (China)
Experimental PLA mulch for field testingSB-PLA-10 high MW, whiteSB-PLA-11 half MW of (10), small fiber size, blackSB-PLA-12 blended with PHA (20%), black
SCRI Project Experimental BDM
September 23, 2010Mount Vernon
Open field
High tunnel
Weed Control with Biodegradable Mulch High Tunnel and Open Field, Mount Vernon 2010
Total Number (plot-1) Total Weight (g.plot-1)
Tomato Yield with Biodegradable Mulch High Tunnel and Open Field, Mount Vernon 2011
Total Number of Fruit (plot-1) Total Weight of Fruit (kg.plot-1)
Mean Tomato Fruit Quality with MulchesHigh Tunnel and Open Field, Mount Vernon 2011
Supported by CSANR BIOAg grant
Fruit oBrix Fruit % Acidity
Mulch Visual Evaluations
Two times each month measure: Number of rips, tears and holes (RTH) Percent visual deterioration (PVD)
BioBag: 6/17/11 8/1/11 9/2/11 10/10/11
BDM Percent Visual DeteriorationHigh Tunnel and Open Field 2010
Mount Vernon and Knoxville
Mulch - Laboratory TestingFirst Flower
SB-PLA-10 SB-PLA-11
BDM Sample PreparationFirst Flower
BioTeloBioBag
BDM Sample Degradation
Planting
Final Harvest
BioBag BioTelo
Karen Leonas, WSU
BDM % Maximum Load at Final Harvest2010 HT and OF at Mount Vernon, Lubbock & Knoxville
Open Field High Tunnel
Doug Hayes, UTK
Mesh Bag Study Mount Vernon 2011
Oct 2010 BB TX Mar 2011 BT TX Mar 2011
Jennifer Moore-Kucera, TTU
Current Status
Year 2 field studies complete; data are being entered and analyzed
Year 1 and Year 2 preliminary reports posted on Team website http://mtvernon.wsu.edu/hightunnels/
Year 1 results are being submitted for publication Winter 2011
Developed a team website and public website for information sharing