Japanese knotweed composting feasibility study Delaware County NY
Japanese knotweed composting feasibility study, Delaware County, NY Laurence Day, Jessica Rall — Delaware County SWCD Susan Mc. Intyre — Delaware County DPW Charles Terrance — SUNY Delhi
Managing Invasive Species (e. g. Polygonum cuspidatum) • Effect of climate change on invasives = • We need a variety of Disposal Options ?
Problem: Invasives at Stream Rehab Sites Stream Rehab & Realignments � [photo of knotweed at stream site]
Drying extricated plants for burning, during a wet summer…
Delaware County Solid Waste Composting Facility, Walton Why not compost removed knotweed? Might this compromise weed-free status of the county’s compost? Biosolids composting requires sustained temperatures ≥ 55° C for 3 consecutive days.
“Sentinel Chamber” LIVE (Compost)
Knotweed sample collection site
30 Samples each of 4 Tissue Types
Wrapped in Nylon Netting “Wontons”
Compost+Wanton+Compost+…
Filled “Knotweed Sentinel”
Four Treatment Groups + Control 1. Three sentinels buried in compost for 3 days. 2. Six sentinels buried in compost for 6 days. 3. Moist heat only, 52° - 55° C for 3 days. 4. ‘Equipment blank’ placed samples in wontons & sentinels, then into growth chamber for 6 days. 5. Control Group planted directly into growth chamber at SUNY Delhi.
Nine Sentinels Buried in Compost Two Groups: 3 -days or 6 -days 55° - 63° C, mean=61. 3° C (142° F)
Moist Heat Treatment 52° - 55° C for 3 consecutive days
Inspection and Potting
Growth Chamber, Summer Conditions 27° C “days” (lights on) 19 ° C “nights” (lights off)
100% GROWTH vs. 0% GROWTH CONTROL GROUP COMPOST-BURIED GROUP
RESULTS � Both composting (≥ 3 d at >55° C) and moist heat (≥ 3 d at 52°-55° C) effectively killed all growth of roots and crowns (P<. 01). � Root and Crown samples much more likely to sprout and grow than leaf or stem samples. � Sentinels performed well, although heat softened plastics; careful removal needed.
Conclusions � Temperatures adequate to safely compost biosolids are also appear effective on Japanese knotweed vegetation. � It appears feasible to compost knotweed at the Delaware County SWM facility, not compromising “weed-free” status of compost. � Simple, inexpensive “Sentinels” proved useful to safely assess composting feasibility for invasives.
NY Biosolids Composting Locations (26 Locations in 19 Counties)
Epilogue ↗
- Slides: 21