Contaminated Manure

national | environment | news report Saturday October 03, 2009 09:33 by Tony Adams - Cork Food Web

Gardeners and growers take note

I am writing this article to draw attention to the fact that vegetable growers can no longer be sure that farmyard manure, (including horse manure), is safe to use. There have been huge problems since last year where contaminated manure has led to stunted and grossly deformed vegetables in thousands of gardens, allotments and farms across the UK and the US, and now Irish gardeners are starting to be affected too. Potatoes, tomatoes, peas, beans, carrots and salad vegetables are all vulnerable, and there have been reports of damage to onions, leeks, raspberries and even a newly-planted tree; though, worryingly, some vegetables such as courgettes appear unaffected when grown on the same contaminated manure.

The cause is a new, hormone-based weedkiller: aminopyralid, which is most commonly sold under the trade-names Forefront and Pharaoh. It is used to kill thistles, docks and other broad-leaved weeds growing in grassland without killing the grass too. It seems that what happens is this: the herbicide is sprayed onto grassland; the grass is later cut for hay or silage; this is then fed to cattle or horses; and the chemical remains active right through their guts and into their manure. This means that even if a farmer never uses this weedkiller the manure from his/her animals might still be contaminated if hay or silage was bought in from another farmer who did use it. Straw might also be affected if this herbicide is used on a cereal crop.

Dow AgriSciences, which manufactures aminopyralid, has posted advice to allotment holders and gardeners on its website: “As a general rule, we suggest damaged produce (however this is caused) should not be consumed.” Those who have already used contaminated manure are advised not to replant on the affected soil for at least a year. Also, stacked manure may remain toxic for years, as the herbicide only really starts to break down when it comes into contact with the soil.

Following a huge outcry in the UK, Dow voluntarily withdrew aminopyralid from sale there, although there have since been moves to reintroduce it. It was first licenced for use in Ireland in August 2007 and has not been withdrawn here; as I write Forefront is for sale in my local farm-supply store as it may well be in yours.

I have raised these concerns with Minister Brendan Smith at the Department of Agriculture and also with our so-called “Green” Minister for Food Trevor Sargent. Interestingly, their replies, although written months apart, both use the industry-preferred and rather Orwellian phrase “plant protection product” for “herbicide”, and both include, word for word, the same assurance: [I am…] “satisfied that, when this product is used in accordance with label instructions, it can be a very useful tool in the control of weeds (including noxious weeds) without any negative consequences for man, animals or for the environment.” T’would make you wonder who the ventriloquist might be….

Further information can be had by typing “aminopyralid” into your favourite search-engine. Some of the personal stories related by gardeners affected by this are quite heart-rending. Also, please spread the word amongst any gardeners you know, it’s no use waiting for the mainstream media to do so. And don’t even start to think about the milk…