Comparison of Agricultural Runoff between Organic Farming and Conventional Chemical Farming

Transcription

1 Comparison of Agricultural Runoff between Organic Farming and Conventional Chemical Farming Nicole David San Francisco Estuary Institute, Oakland, CA Fred Thomas CERUS Consulting, Chico, CA California Certified Organic Farmers Foundation Camino, CA

2 Acknowledgements CCOF Foundation State Water Resources Control Board

3 Going Organic Project Address environmental and social concerns Offer innovative and economically viable options for growers Desired outcome: Pesticide and nutrient load reduction in receiving water bodies

4 Going Organic Project (Walnuts) BMPs in Stonefruit Project Sustainable Cotton Project

5 Organic Walnuts Organic pesticides Cover crops

6 Organic Walnuts Organic pesticides Cover crops Monitoring of insects and insect fertility Pheromone disruption Beneficial insect release

7 Organic Walnuts Organic pesticides Cover crops Monitoring of insects and insect fertility Pheromone disruption Beneficial insect release Filter strips Compost

8 Field Methods Samples collected from tail ditches Samples collected during flood irrigation and first winter storm Samples analyzed for WQ parameters, SQ parameters, pesticides, nutrients, pathogens, and benthic organisms

9 All Chemicals Detected in Water 1 Cypermethrin Cyfluthrin Permethrin Dimethoate Fenpropathrin Esfenvalerate Lambda-Cyhalothrin Bifenthrin Diazinon Chlorpyrifos % of ALL Samples with Detection Preliminary data. Do not cite or quote

10 All Chemicals Detected in Sediment Fenpropathrin Esfenvalerate Lambda-Cyhalothrin 1 Bifenthrin Diazinon Chlorpyrifos % of ALL Samples with Detection Preliminary data. Do not cite or quote

11 April 2008 Irrigation Runoff 0.02 ug/l 0.01 ug/l 0.02 ug/l 0.01 ug/l Org Conv Diazinon Cypermethrin Lambda Cyhalothrin Permethrin Preliminary data. Do not cite or quote.

12 April 2008 Sediment Samples 8 ng/g 8 ng/g 4 ng/g 4 ng/g Org Conv Bifenthrin Esfenvalerate Fenpropathrin Lambda-Cyhalothrin Preliminary data. Do not cite or quote.

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14 Diazinon in Water Org Conv Diazinon (ug/l) Sampling Events Preliminary data. Do not cite or quote.

15 Bifenthrin in Sediment Org Conv 30 Bifenthrin (ng/g) p = 0.002, t-test Sampling Events Preliminary data. Do not cite or quote.

16 Bifenthrin and Lambda-Cyhalothrin Org Bifenthrin Conv Bifenthrin Org Lambda-Cyhalothrin Conv Lambda-Cyhalothrin ug pyrethroids/ g TOC Sampling Events Preliminary data. Do not cite or quote.

17 Diazinon Loads Conv Org Load (mg/h) Sampling Events Preliminary data. Do not cite or quote.

18 Average Loads (mg/h) Pesticide Org Sites Conv Sites Lambda-Cyhalothrin Diazinon Chlorpyrifos Dimethoate Esfenvalerate/Fenvalerate Preliminary data Do not cite or quote

19 SSC Loads SSC Loads Org SSC Loads Conv Loads (kg/day) Sampling Events Preliminary data. Do not cite or quote.

20 Median and Maximum Nutrient Concentrations (mg/l) Nutrient Org Sites Conv Sites Nitrate + Nitrite 0.13 (13.4) 1.73 (190) TKN 1.29 (14.7) 2.67 (45.6) ortho-phosphate 0.49 (1.3) 0.29 (7.6) Total Phosphorus 1.00 (6.1) 0.57 (7.0) Preliminary data Do not cite or quote

21 Pathogen Indicators Total Coliform Org Conv Total coliform (MPN) NA NA Sampling Events Preliminary data. Do not cite or quote.

22 Bioassessment 10 Org Individuals Conv Individuals Sampling Events Org # of Taxa Conv # of Taxa Preliminary data Do not cite or quote Sampling Events

23 Conclusions Organic orchards not free of pesticides Bifenthrin concentrations above LC 50 at conv sites (44%) and organic sites (5.3%) Nutrient concentrations in general high but lower at org sites No increased risk for pathogens

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