December's issue of the Sustaining the Pacific Northwest newsletter
(
http://csanr.wsu.edu/whatsnew/PNW-v2-n4.pdf) contains a couple of
articles that may be of interest to this list. Excerpts follow:
1. WSDA Compost Sampling Study Shows Clopyralid Ban is Working
The WSDA rule prohibiting most uses of clopyralid in turf went into
effect in the spring of 2002. The results of our study show that the
rule is having the desired effect of reducing clopyralid residues in
compost produced at composting facilities. However, results also show
that clopyralid-containing feedstocks are continued to be used in
eastern Washington composting facilities.
WSDA reminds growers that grass hay or straw from fields or pastures
treated with a clopyralid-containing product cannot be used as
feedstocks at a compost facility.
2. Anaerobic Digestion
Other co-products from digesters include fiber, nutrient water, heat,
struvite, and CO2. Fiber can be used for lower-value products such as
organic soil amendments and animal bedding, or for potentially
higher-value products such as a peat moss replacement in potted plant
production. Nutrient-rich water serves as fertilizer since the nutrients
are readily available for use by plants. Struvite is a high-quality,
organic phosphorus fertilizer, waste heat from the electrical generation
process can be used to heat water, and CO2 can be "scrubbed" and
captured from the biogas. More research is necessary on all of these
co-products to improve the quality and consistency of the anaerobic
digestion products and to develop and capture value-added markets.
Best wishes for the New Year!
Hugh
Received on Sat Jan 01 2005 - 21:45:56 EST