Date: Fri, 20 Feb 1998 14:14:09 +0000
From: "Steve Diver" <steved@ncatark.uark.edu>
Subject: Drip irrigation in organics: trouble shooting
A grower is raising thousands of organic greenhouse herbs
via pot culture and has trouble with clogging in the drip
irrigation system.
Diluted sulfuric acid is used as a clog preventer in drip systems
in standard horticultural production systems that do not adhere
to certified organic standards.
What are some alternatives that would pass for certified organic?
Does anybody have any tips on acceptable vs prohibited, efficacy,
sources, costs, and dilution rates for the following?
Potential substances to un-clog drip irrigation tubes and emitters in
certified organic horticulture production:
* Baking soda
* Acetic acid (vinegar, concentrated)
Synthetic definition Section 2103 (21) differentiates between what is
acceptable and not acceptable. Under OFPA, all synthetics are prohibited, all
natural substances Section 2105 (1) (any substance that does not fall into the
synthetic category and is not prohibited specifically on the National List is
acceptable.) Only the active synthetic substances in the categories detailed
in Section 2118(c)(1)(B)(i) can be considered for use in organic farming. Any
such proposed active synthetic substance being considered for use in organic
farming must be itemized by specific use or application per Section 2118(b).
There is no category of irrigation clog preventer or corrector for
consideration. The above two, if the baking soda is mined and does not become
a synthetic by the how it is handled is acceptable. Organically produced
acetic acid is acceptable. The bottom two synthetically substances are
probably unacceptable. I believe commercial hydrogen peroxide is
synthetically produced per the OFPA definition.
* Phosphoric acid (food grade, concentrated)
* Hydrogen peroxide (35%, concentrated)
I'll pass on any suggestions. Thanks!
It was unclear Steve whether the herbs were for sale as transplants to be
grown for production on a certified organic farm or for harvest in a certified
organic greenhouse site and sold wholesale or retail for consumption as
organically produced. There is a difference in how the plants can be treated
under OFPA based on whether they are transplants or food while under the
greenhouse management.
It they were for sale as transplants, refer to Section 2109(c) and (c)(3)
which states no synthetic substances could be used and no prohibited natural
substance could be used to open the clogged emitters. Therefore for plants
being raised as transplants to certified organic land, natural substances like
acetic acid, do not need to be certified organic vineger, but only vinegar not
produced synthetically per the OFPA definition.
Steve Diver
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