1. Use of Biodegradable Mulch for Vegetable Crop Production M. D. Orzolek Dept. of Horticulture The Pennsylvania State University

2. Non-degradable plastic film - 1.0 mil

3. Different mulch colors-ND

4. Silver/black on continuous raised beds

5. Retrieved ND plastic film - What to do with it ?

6. ND mulch residue after 10 years applied in the field

7. Burning plastic mulch in field ?? Polyethylene melts and not incinerates below temps of 1,000 F.

8. PlastoFuel – condensed ag plastics

9. PlastoFuel • PlastoFuel is made by condensing ag and consumer polyethylene and polypropylene plastics. It was developed at Penn State by Garthe Lemont and Orzolek. It was tested in a Korean burner that changed the plastic from a solid to liquid to gas and incinerated @ 2,000°F.

10. Burner which incinerated plastics

11. Degradable Plastic • Mid-1970’s British and American scientists discover biodegradable plastic derived from cornstarch. • In 1996, four percent of all plastic production was biodegradable at a cost of $2 to $3/pound compared to $0.50/pound for nondegradable plastic.

12. Photodegradable Plastic • Mid 1980’s photodegradable plastic mulch was developed but was very unpredictable in timing of initial degradation. The plastic mulch has to be completely intact for minimally 30 days for crop response.

13. Early plastic degradation prior to crop maturity

14. Biodegradable Mulch • Grower considerations: • Degrades in field - no retrieval • Multiple colors available • Higher product cost compared to non-degradable mulch • Variable widths available - 3’ to 5’.

15. Trial Specifics • Crops: • 2005/06/07/08 • Bell pepper,cantaloupe, and eggplant.

16. Field Design • 3 replications • 12 plants per treatment • In-row-spacing 2’ and between row spacing 6’ to 8’. • All crops were established from locally grown transplants.

17. Field Observation -7/22/05 • All biodegradable mulch colors were brittle with longitudinal cracks (tears) in plastic. Approximately 10% to 15% of soil visible on raised bed. Currently, few if any weeds in row with crops.

18. Longitudinal tear in mulch Mulch may tear during application in the field.

19. Degradation of mulch along soil line Biodegradable mulch will initially degrade along soil line on shoulder of bed.

20. Field Observation -10/20/05 • Retrieved non-degradable black and blue plastic mulch and drip tape from field. Biodegradable mulch colors were approximately50% to 60% degraded.

21. Biodegradable Mulch

22. Field Observation - 7/12/06 • The brown BD mulch appeared to be degrading faster than either the black or green BD. Less mulch breakdown with melon crop compared with pepper crop. No difference in crop growth between non-degradable and biodegradable plastic mulches.

23. Field Observation - 8/24/06 • On the average, 30% to 50% of soil was visible in beds where BD mulch had degraded. Significant weed growth observed in row when soil was not covered with plastic mulch.

24. 2005 Marketable Pepper Yield

25. 2006 MarketablePepper Yield

26. 2007 Marketable Pepper Yield

27. 2008 Pepper Trial

28. 2005 Marketable Melon Yield

29. 2006 MarketableMelon Yield

30. 2008 Melon trial

31. 2008 Field Trials

32. 2008 Field Trials

33. 2008 Field Trials

34. 2008 Eggplant Trial

35. Soil Temp - 7/14 at 1:00pm - 2” below soil

36. Conclusions from study • Yield of both pepper and cucurbit fruit from plants grown on biodegradable plastic mulch is equal to or sometimes higher compared to pepper and cucurbit crops grown on non-degradable plastic mulch.

37. Conclusions from study • Biodegradable (BD) plastic mulch does not have to be retrieved from field, but can be incorporated with a rototiller or disk in the fall. • It appears that BD mulch will start to degrade about 45 to 50 days after laying the mulch in the field.

38. Incorporating biodegradable plastic mulch-9/23/08

39. Conclusion from study • Response of various vegetables to mulch color similar in both non-degradable and biodegradable plastic mulch.

40. Conclusions from study • Under dry or drought conditions, the rate of degradation of BD plastic mulch is slower compared to growing seasons with weekly rainfall. • If BD mulch degrades earlier than 45 days, weed populations may be very competitive with crop - exception 2008 field study.

41. Grower considerations with BD mulch • Initial cost of roll of BD plastic mulch about 50% higher than ND mulch. • Currently, rolls of BD mulch available in 3, 4,or 5 foot widths.

42. Any questions? from audience