1. Assessment of Biodegradability of Mulches Sathiskumar Dharmalingam (MATERIALS WG) Dr. Douglas G Hayes SCRI MEETING,06/02/2011

2. Objective of My Research project To compare and understand fundamental aspect of Biodegradation studies in the open fields and high tunnels to greenhouse to ASTM D5988-3(Standard Test Method for Determining Aerobic Biodegradation of Plastic materials in soil or Residual Plastic materials After Composting) Improve methodology for biodegradation of agricultural plastics in the soil

3. Greenhouse Study II of Biodegradable Mulches(BDMs) at UTK Duration(15 week, started on 1 st April,2011) 3 Mulches (2 replicates of each) – Meltblown(“MB”) Polylactic acid(PLA) i.100% Polylactic acid (PLA)(W/W) ii.75%PLA & 25%Polyhydroxybutyrate(PHB) – Spunbond(“SB”-2011) PLA ------------> black(Low MW)(Dr.Wadsworth) 3 Soil treatments(Manure +Water, Manure + Water+ Pineapple juice(PJ) and Manure+ Water+ No Pineapple juice(PJ)) Mulches buried 2 cm below surface of soil Treatment per tray per 48 hr

4. RBD with sampling-Strip plot SOIL+ MB- 75%PLA 1L H 2 O+ MB- 100%PLA PJ SB PLA SOIL+ MB- 75%PLA 0.5L H 2 O+ MB- 100%PLA PJ SB -PLA SOIL+ MB- 75%PLA 1L H 2 O+ MB- 100%PLA NO PJ SB-PLA SOIL+ MB- 75%PLA 0.5L H 2 O+ MB- 100%PLA NO PJ SB-PLA SOIL+ MB- 75%PLA) 0.5L H 2 O MB- 100%PLA LOW MO SB- PLA SOIL+ MB- 75%PLA 0.5 H 2 O MB- 100%PLA LOW MO SB- PLA SOIL+ MB- 75%PLA) 1L H 2 O MB- 100%PLA HIGH MO SB-PLA SOIL+ (MB- 75%PLA) 1L H 2 O (MB- 100%PLA) LOW MO (SB-PLA)

5. BDMs MB-100% PLA MB-75% PLA and 25% PHB SB2011-PLA

6. With and Without PJ treatment trays after 2 months

7. High and Low moisture content trays after 2 months

8. Analysis on BDMs Tensile strength(breakage and elongation) BDM density g m -2 Thickness Change in Mol Wt-Gel Permeation Chromatography Scanning Electron Microscopy Soil moisture and Temp-Sensor No air permeability No porosity No soil testing for week 15

9. ASTM D5988-3(Standard Test Method for Determining Aerobic Biodegradation in Soil of Plastic materials or Residual Plastic materials After Composting) Require a common microbe and soil type Desiccator CO 2 measured by Ba(OH) 2 3 replicates required Prospective: Will learn in July by visiting Michigan State University in Dr. Ramani Narayan’s lab.

10. Challenges in the prospective improved methodology Accelerate the biodegradation rate Higher temperature(37 o C??) Inoculating selective microbes(Abiotic or biotic) ???? Low scale?????

11. QUESTIONS?????