Contaminated Composted Manure
Thanks to GardenRant for the lead on contaminated manure in the U.K. This story actually got me thinking because my daughter – raising lettuce and tomatoes in containers in Toronto – claimed this past weekend that she and her partner got sick when they ate their lettuce. Now this was containers with potting soil and she used some purchased composted manure and claimed she washed the lettuce really well.
Here’s the EPA link to the datasheet.
The concern seems that it survives the gut action of ruminants and stays active in the manure pile. Studies submitted to the EPA show that “Under aerobic conditions, degradation of aminopyralid in five different soils resulted in the production of CO2 and non-extractable residues. Half-lives ranged from 31.5 to 533.2 days in 5 soils. For risk assessment purposes, EPA used a half-life of 103.5
days. ” So it can stay active and kill crops in soil for up to a year and a half. And it seems it stays alive after passing through the guts of cows.
Now, the toxicity on humans would seem that the major problem (according to the this factsheet) is dermal irritation although you may read it a little more carefully than I did and find something else of concern. So this isn’t likely what created the problem for my daughter.
She did say she washed the lettuce very thoroughly so that she’s hoping there wasn’t e-coli on it and this was at the height of the tomato concern so we thought it wasn’t necessarily the lettuce. She wiped it off the face of the earth anyway and now it’s composting somewhere.
The bottom line as always though is that you will be further ahead to use your own compost. And if you don’t produce enough, use compost tea. And if you don’t produce compost because you live in an apartment of town house, then get a worm bin. And if you don’t do compost or worm-compost to use as a compost tea starter – then you really can’t call yourself an organic gardener, cause you just don’t get it.
Well I got some (purchased) composted manure here in West Texas and even mixed in with good soil seems to have killed my plants, tomatoes and herbs mostly planted in containers. Anything that did manage to survive I replanted in the garden patch after rinsing all the old soil off the roots. They catching up slowly to the rest of the tomatoes planted directly into the garden soil, enriched with a little organic fertilizer.
@Katharine Karesa -
Katharine – interesting that we haven’t heard about anything down there that was a media “event” with many people having the problem – or commercial operations losing crops. I’d guess you used too much in the containers.
if I had to make a guess. But it’s frustrating to be sure. Let me remind folks that composted manure isn’t necessarily compost and if it isn’t produced properly can still contain e-coli. Proper compost (without the manure) doesn’t contain any e-coli.
I think I used too much as well. I had used all my homemade compost (there wasn’t much, it’s super dry here this year) in my veggie garden. So it was the first time I had used composted manure. It will also be the last