[Sebona]

Hi, My name is Sebona, I have cultivated an allotment in Manchester, for 4 years with great success. Unfortunatly       I used farm manure, which it since turns out, has been contaminated with weed killer. does any body know how long it might last, in the soil. thanks

[BussinSpain]

hi, do you know (or can you find out) if it was a systemic or a contact weed-killer?  Any info from the farmer would be helpful.

[Sebona]

Hi, thanks for interest, all I know about the contaminant is its sprayed on straw crops to suppress weeds, but does not harm horses. Sebona.

[8doubles]

I have just read that aminopyralid can last 3 years in the soil or 5 years if left in a heap !

[BussinSpain]

Sebona, can you spread the heap out to let the weather get to it either bake out or water down the contaminant?  Try and ask the farmer what was sprayed on the straw - explain your predicament and I am sure he will help you.

[mumofstig]

John's advice here
http://allotment-garden.org/garden-diary/273/aminopyralid-contaminated-manure/

[Nobbie]

I had the same problem about three years ago when I used manure to plant my potatoes and they came through all distorted. I dug them up along with as much of the manure as possible and disposed of it in an uncultivated area of the site. The next year I planted onions which were fine and then sweetcorn. There are some crops which are not badly affected, so try these. Also it is important to keep the soil well cultivated so that the bugs in the soil can get to work breaking the weedkiller down. Probably best not to use green manure as these will take up the weedkiller and recycle it into the soil when dug in. Maybe stick with chemical fertilisers so that the organic matter which holds the weedkiller in the soil gets decomposed more quickly.

[Sebona]

Thanks to everyone who has helped me with this problem. I shall be following the advice and info I have recieved, next year will grow only flowers,till I know its safe again. will let you know how I get on. Sebona.

[Spr0ut]

Try growing a quick crop or green manure on it now - if it comes up green you have got away with it but if it doesn't germinate or comes up and then dies off you have problem manure.

[mumofstig]

Green manures are not really a good idea, although some will grow, for the reason already given

Probably best not to use green manure as these will take up the weedkiller and recycle it into the soil when dug in.

John (the site owner) suggests

If you suspect your manure is contaminated, the way to test is to start a few tomato plants off and transplant them into a compost with 50% manure. Make sure the manure is chopped finely or shredded and well mixed.

If the plant shows the distorted leaves typical of hormonal weedkiller damage then you know you have the problem.

quote taken from the page linked above.

[beesrus]

How sad for you Sebona  if your soil is now contaminated with aminopyralid. Very very difficult to know how to proceed if your plot actually has been contaminated... just about the worst thing that can happen to us allotmenteers, and an ongoing reminder how foolhardy the industry can be. And that's before we even get onto the GM debate, and for instance, the GMO3 soya that can harbour our old friend glyphosphate residuals in soya grown for human consumption all over the world. And to cover their tracks on that little beauty, the authorities have increased the safe legal limit of glyphosphste in our food by 50 times and even more, up to 200 times, in some circumstances.

I really don't get the suggestion of only using chemical fertilisers on your plot for a while in this case, let alone the irony, as the last thing those chemicals will do is help the natural bugs in the soil soil to do their thing in clearing out the weedkiller asap. BFB would be the best fertiliser for ongoing growing surely. Digging over and more digging over to aerate the soil seems to be the only answer on offer, along with hoping for copious amounts of rain, as I would imagine getting rid of the contaminated manure along with half your topsoil isn't really a viable option for most people. If it were me, I would be tempted to grow a short growing green manure to pull the poison out of the soil, and then lift it and burn it, but I'm no scientist.
We all grow in fear of being contaminated by this stuff, and while I would love to be wrong, I think I'm right when I say the authorities that be are still allowing this poison and it's inherent problems that appeared 6 years ago to be still used in the industry, and that there is nothing legally stopping it finding it's way into "organic" labelled gardening products, including manure.