PERSISTENCE OF IMPRELIS DURING COMPOSTING

Transcription

1 PERSISTENCE OF IMPRELIS DURING COMPOSTING Frederick C. Michel, Sukhbir Grewal, Yan Ming Li, Sandra Munoz-Castaneda The Ohio State University, OARDC, 1680 Madison Ave., Wooster, OH USA Food, Agricultural and Biological Engineering

2 Introduction Fate of commonly used herbicides during composting Effects of herbicides in growing media on bean growth Aminopyralid Aminocyclopyrachlor Clopyralid Trifluralin Imprelis and Clopyralid persistence during composting Composting Imprelis damaged conifers. Conclusions Food, Agricultural and Biological Engineering

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5 Conversion to CO2 (%) Pesticide mineralization during composting ,4-D Carbon Conversion Time (days)

6 % of added 2,4-D 14 C 2,4-D CO2 Water extract Organic extract Volatilized Humic material Unextractable 0 Initial Compost

7 Thermophilic 2,4-D degrading Bacillus isolated from Compost

8 New Generation of Herbicides: Pyrimidine/Pyridine Carboxylic Acids Clopyralid, Aminopyralid, Aminocyclopyrachlor. Active ingredients in over 30 herbicides (Confront, Curtail and Stinger, Banish, Forefront, Halcyon, Pharaoh, Pro-Banish, Runway, Synero and Upfront, Imprelis). Highly effective at low dosages with very low human toxicity. Used to control annual and perennial weeds in crop production and turf as wells invasive weeds in natural areas and pasture. Effective against Creeping Thistle, Creeping Charlie and other noxious, difficult to control perennial broadleaf weeds. Persistence and potency means fewer applications. Compost feedstocks such as turf, manure, dead trees and hay may can contain residual amounts of these herbicides.

9 Pyrimidine/Pyridine Carboxylic Acid Herbicides DPX - MAT28 Aminocyclopyrachlor 6 - amino chlor o Cyclopropyl pyrimidine carboxylic acid Aminocyclopyrachlor (IMPRELIS) CH3 DPX - KJM44 Aminocyclopyrachlormethyl 6 - amino chloro Cyclopropyl pyrimidine carboxylic ac id methyl ester IN - LXT69 Inactive Metabolite 6 - amino chloro Cyclopropyl pyrimidine Aminopyralid 1-amino 3,6 - dichloro Pyridine carboxylic acid Clopyralid 3,6 - dichloro Pyridine carboxylic acid

10 Clopyralid detections in Composts at phytotoxic levels (11/2002)

11 HOME-GROWN VEG RUINED BY TOXIC HERBICIDE The Observer, Sunday 29 June 2008 ONE YEAR LATER: PERSISTENT HERBICIDES IN COMPOST. Bezdicek, D., M. Fauci, D. Caldwell, R. Finch, and J. Lang Biocycle, 42 (7): CITY COUNCIL FIGHTS BACK: NEW ZEALAND CITY CONFRONTS CONTAMINATION. Fietje, G Biocycle, 42 (7): 31. PERSISTENT HERBICIDES IN COMPOST, ORGANIC FARMS, FOLKS, AND FOODS. Biggert, A The Northeast Organic Farming Association of New York (NOFA), Mid-Winter: COMPOSTING FACILITY NOT ACCEPTING NEW WASTE. Wendy Harris The Spokesman-Review, Spokane, WA. Thursday, April 18, 2002 SANTA ROSA MOVES TO PROTECT COMPOST: FEARFUL OF DAMAGED PLANTS FROM WEEDKILLER, CITY WON'T INCLUDE YARD WASTE IN COMPOSTING PROCESS. Mike McCoy The Press Democrat, Santa Rosa CA, April 19, STOP THE KILLER COMPOST! Green, Emily The Los Angeles Times, Los Angeles, CA, Mar 4, 2002.

12 Issues with Clopyralid Concentration in grass clippings the day of application is 54,000 ppb (sprayable formulation) to 16,000 ppb (granular formulation). Half life in soil up to 250 days. After 10 weeks, clopyralid averages 150 ppb in turf. Concentrations of < 10 ppb can affect sensitive plants. Tomato, sunflower, potato, peas most susceptible Symptoms include leaf cupping, loss of apical dominance, prevention of fruit set.

13 Imprelis related damage to conifers in 2010

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16 Phytotoxicity Experiment Composts incorporated into potting media at 4 to 20% Dairy Manure compost, Yard trimmings compost Herbicides added to media as liquid Concentrations used (ug/kg in growth media dry weight basis) Aminopyralid 0, 10, 50, 100 ppb Clopyralid 0, 5, 25, 50 ppb Trifluralin 0, 100, 200, 1000 ppb Imprelis 0, 10, 50, 100 ppb Bean sown into media. Germination and plant growth assessed for 35 days.

17 Yard Trimmings Compost 0% 5% 10% 20%

18 Dairy Manure Compost 0% 5% 10% 20%

19 Aminopyralid in YT (ppb db) Concentration values are the overall concentrations in the media.

20 Aminopyralid in DM (ppb db)

21 Clopyralid in YT (ppb dw)

22 Clopyralid in DM (ppb dw)

23 Trifluralin in YT (ppb)

24 Trifluralin in DM (ppb)

25 Imprelis in YT (ppb dw)

26 Imprelis in DM (ppb dw)

27 Objectives 1. Investigate the extent of biodegradation of aminocyclopyrachlor (Imprelis) and clopyralid containing grass during composting 2. Conduct experiments under conditions that mimic full scale composting (eg. Feedstock mix, C:N ratio, moisture content, temperature, ph, etc). 3. Determine the phytoxicity levels of composts containing these herbicides

28 Methods Grass field plots established that received one of four treatments: Untreated (UT) Granular mixture of free acid and methyl ester of aminocyclopyrachlor (GH) Liquid application of aminocyclopyrachlor mixture (LH) Liquid application of Clopyralid (CH). Herbicides applied as directed Granular aminocyclopyrachlor: 84 g AI/hectare irrigated into the turfgrass within 24 hours. Liquid aminocyclopyrachlor: 84 g AI g per hectare Clopyralid: 209 g AI/ha. Clippings collected to allow for maximum absorption into the grass after 7 days for the granular application after 1 day for the liquid applications Grass amended with leaves at a 2:1 mix ratio and composted in lab scale system. Compost samples removed and extracted with three solvents, purified and analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS). Limit of quantitation = 10 ng/g (parts per billion).

29 Experiment 1 Compost in a large scale adiabatic system (no heat input or loss) Reactor volume 200 liters Compost for 90 days Treatments 1 - granular application at lb AI/acre 2 - granular application at lb AI/acre 3 - liquid application at lb AI/acre 4 - liquid application at 0.04 lb AI/acre

30 Day 0 Day 90

31 Organic Matter Loss 100% 80% Granular Granular Liquid Liquid % OM loss (% of initial) 40% 20% 0% Time (day)

32 Imprelis (mg/kg ash) Aminocyclopyrachlor loss (ash basis) Time (day) Granular Granular Liquid Liquid 0.04

33 9 8 7 Aminocyclopyrachlor loss (dry weight basis) Granular Granular Liquid Liquid 0.04 Imprelis (mg/kg dw) Time (day)

34 5 4 Aminocyclopyrachlor loss (wet basis) Granular Granular Liquid Liquid 0.04 Imprelis (mg/kg wet) Time (day)

35 Experiment 2 Compost grass samples treated with aminocyclopyrachlor and clopyralid in small scale compost system Use replicated treatments Reactor volume 4 liters Determine whether long term (180 day) composting leads to herbicide degradation Generate Imprelis and Clopyralid contaminated composts for plant growth studies.

36 Composting Reactor System Incubator 55 C. Dry Offgas Air Flow Restrictor 100 ml/min Compost (~ 1 kg wet) Leaves + Grass 2:1 IR CO 2 Detection Polargraphic Electode O 2 Detection Water NH 3 trap Boric Acid (4 C) Data Logger (Temp., O 2, CO 2 )

37 Bioreactor vessels for composting simulation

38 Bioreactor Vessels Bioreactor System Bioreactor incubator CO 2, O 2 and temperature measurement, calibration and data acquisition. Flow restrictor system (air 100 ±3 ml/min) Water condensor and ammonia trap (9 C.) Data collection computer

39 Initial Properties of Compost Mixes Table 1. Initial properties of compost mixes (Data from soil testing and Research laboratory) Untreated Granular Herbicide Treatments Liquid Herbicide Clopyralid Moisture (% wet) 68.2 ± ± ± ±0.3 ph 6.8 ± ± ± ±0.1 Volatile solids (% dry) 84.5 ± ± ± ±0.6 C (% dry) 46.0 ± ± ± ±.5 N (% dry) 1.8 ± ± ± ±0.06 C:N ratio 26.1 ± ± ± ±0.73 P (mg/g) 2.6 ± ± ± ±0.1 K (mg/g) 9.7 ± ± ± ±0.20 Values are averages of triplicate reactors ± standard deviation.

40 Figure 3. Cumulative conversion of carbon to CO 2 during composting. Values are averages of triplicate reactors ± standard deviation. UN: Grass untreated ACP-G: Grass treated with aminocyclopyrachlor granular formulation ACP-L: Grass treated with aminocyclopyrachlor liquid formulation CLO: Grass treated with Clopyralid.

41 Recovery of Aminocyclopyrachlor during composting (Granular formulation DPX-MAT 28 )

42 Recovery of Aminocyclopyrachlor during composting (Liquid formulation DPX-MAT 28 )

43 Aminocyclopyrachlor Metabolite formation during Composting Imprelis (mg/kg) 0.70 IN-LXT69 (mg/kg) Untreated Aminocyclopyrachlor IN-LXT69 (metabolite) Time (Days)

44 Recovery of Clopyralid during composting

45 Table 3. Concentrations of aminocyclopyrachlor (DPX-MAT 28) and clopyralid in compost mixes on wet, dry and ash basis. Sample day Treatments (Values are mg/kg) Untreated Granular Herbicide Liquid Herbicide Clopyralid wet wet dry ash wet dry ash wet dry ash Day 0 NT 1.5± ± ± ± ± ± ±4 112± ±54 Day 1 0 NT 2.0± ± ± ± ± ± ±5 142± ±60 Day 30 NT 2.9± ± ± ± ± ± ±1 99±2 413 ±13 Day 50 NT 3.0± ± ± ± ± ± ±4 104± ±51 Day 78 < ± ± ± ± ± ± ±4 81± ±56 Day 100 < ± ± ± ± ± ± ±4 109± ±34 Day 178 NT 2.5± ± ± ± ± ± ±2 57±3 194 ±16 % Loss +67% -8% -47% +82% -20% -57% -9% -49% -71% Values are averages of triplicate reactors ± standard deviation. NT = Not tested

46 Are the composts phytotoxic? Methods Incorporate composts made from herbicide treated grass into potting media at 4, 10 and 20% Sow Cucumber, Tomato and Bean into media. Assess plant growth for 35 days. Concentrations in the media overall were the following for the 3 different mix levels: ppb in compost (dw basis) Imprelis Granular Liquid Clopyralid 4% % %

47 Triplicate pots

48 Day 35 Bean Plant Untreated Compost

49 Day 35 Bean Plant 192 ppb 480 ppb 960 ppb Granular Aminocyclopyrachlor Compost

50 Day 35 Bean Plant 428 ppb 1070 ppb 2140 ppb Liquid Aminocyclopyrachlor Compost

51 Day 35 Bean Plant 2280 ppb 5700 ppb ppb Clopyralid Compost

52 Day 35 (4% potting mix) Tomato 192 ppb 428 ppb 2,280 ppb Cucumber

53 Day 35 (10% potting mix) Tomato 480 ppb 1070 ppb 5,700 ppb Cucumber

54 Day 35 (20% potting mix) Tomato 960 ppb 2140 ppb Cucumber

55 Conclusions Mass balance analysis showed that 53% of the granular aminocyclopyrachlor, 42% of the liquid aminocyclopyrachlor and 30% of the clopyralid were present after 178 days of composting. Composting appeared to raise the concentration at which phytotoxic effects were first observed for aminocyclopyrachlor from ~10 ppb to ~100 ppb, possibly due to organic matter interactions. The final concentrations of all of the herbicides of 4.8, 10.7 and 57 ppm (dry wt), respectively, were well above the levels of <0.1 ppm likely to affect sensitive plants. Dilution of treated composts would need to be on the order of 50:1 to prevent growth effects. Plants had different sensitivities to herbicide residues. Tomatoes most sensitive to clopyralid, beans to aminocyclopyrachlor. Food, Agricultural and Biological Engineering

56 Recommendations Although Imprelis has been removed from the market, compost producers should be cautious about accepting dead conifers for composting. If they do, they should be composted separately. If Imprelis is reintroduced, or incorporated into homeowner fertilizer mixes, grass collected in the Spring should be composted separately and the compost produced from the grass tested using a bean bioassay for phytotoxicity prior to sale. Bioassays for aminocyclopyrachlor are needed to effectively test for herbicide contamination of composts.