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  • From: sora <sora AT coldreams.com>
  • To: market-farming digest recipients <market-farming AT franklin.oit.unc.edu>
  • Subject: [Fwd: Persistent Herbicides in Compost:]
  • Date: Wed, 03 Oct 2001 12:58:36 -0700


--- Begin Message ---
  • From: SCook21809 AT aol.com
  • To: csa-L AT prairienet.org
  • Subject: Re: Persistent Herbicides in Compost:
  • Date: Wed, 3 Oct 2001 14:12:19 EDT
Well, this year was a surprising year for me on our farm. I have been
farming using organic methods for ten years. Compost has always been the
right arm of my soil fertility program. Cover cropping is the other arm.
The only parent material
for the compost I made was horse manure and straw from stable sweepings.
I have been monitoring my soil improvement with a comprehensive soil
analysis every two years. I usually add 7 tons of finished compost per acre
as either a soil conditioner or as mulch for weed control.
This year I was shocked to see what appeared to be herbicide damage in
one of my pole bean cultivators and my determinate tomato crops. They had
deformed shoot and leaf development, significantly decreased and delayed
bloom and fruit development.
I happened to read an article in "Biocycle" about a research study
performed by WSU Extension which identified two herbicides which failed to
bioremediate in the composting process. I contacted the faculty member in
charge of the research and the grad student doing the research. They
directed me to a lab where I could get my compost analyzed for the two
persistent herbicides they had found; clopyralid and picloram.
My compost was found to contain clopyralid. The sample had 3 micrograms
per Kg. Arguably, 3 micrograms of clopyralid per Kg may not be enough to
cause the crop damage I witnessed. However, It may be enough to revoke a
certificate for Organic production. I suspect the clopyralid concentration
was higher last spring because the compost windrow I sampled has been
uncovered since May and was less than a foot deep. Interestingly, the
windrow has grown no weeds since it was uncovered five months ago.
I was unable to source the straw used for bedding and the oats fed to
the horses. They were sold by a local feed store who buys from a bulk
distributor. I have switched my parent material for composting to stable
sweepings from an Organic goat dairy.
Currently Dow is seeking to get clopyralid registered under some general
use "weed and feed " products in New York. It and picloram have been
registered in several states already under general use "weed and feed"
products. But turf composting is not the only threat. My source of
clopyralid came from straw and oats grown on conventional farms in Eastern
Washington.
Not only does this inhibit my composting operation. It also affects
municipalities that are composting yard waste as an alternative to dumping it
in landfills. Because these herbicides have demonstrated abilities to resist
bioremediation they will most likely move with the ground water into streams
and rivers unchanged where they may affect our endangered salmon and other
aquatic life.
As frustrating as this problem is, I wish to commend WSU Extension for
being on top of this major threat to organic soil fertility methods and fresh
water contamination. The Cooperative Extension Service system has come a
long way in the last ten years. I am grateful for their new focus on
sustainability.

Best regards,

Art Biggert
Ocean Sky Farm
Bainbridge Island, WA



--- End Message ---


  • [Fwd: Persistent Herbicides in Compost:], sora, 10/03/2001

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