If you still want to obtain manure you should seek assurances from the suppliers by asking the following question:

Has any herbicide containing aminopyralid been used by the supplier of the manure or by any of their suppliers of silage, haylage or bedding material? (The material treated with the herbicide does not have to pass through an animal to contaminate the manure – it may be present in bedding material that has been swept up with the manure). The most common herbicide that contains aminopyralid is 'Forefront" although there are other products too such as Banish, Halcyon, Pharaoh, Pro-Banish, and Runway.

• Were the horses/livestock that produced the manure fed any forage (grass/hay/haylage/silage) that may have been treated with any products containing aminopyralid, be that forage produced on the equine business/farm where the horses/livestock are kept or from an outside supplier of forage?
• Was the field where the animals browsed spot weeded using any products containing aminopyralid e.g. to remove clumps of docks or ragwort.
• If a contract sprayer has been used does the supplier know which herbicide was used to control any broad leaved weeds growing in fields that animals browsed or from which grass was harvested to make silage, haylage or hay for bedding?
• Is all the manure in the stack from the same source i.e. the same animals, same feed/browsed in the same field, or is it from various sources and just stacked together? All the manure in the stack must be free from contamination.
• Can the provenance of all sources of manure in the stack be traced?
• Do not be fooled by the fact that weeds are growing on the manure heap. The amount of herbicide required to kill weeds is far higher than is needed to kill sensitive plants.

 

In order to give these assurances your supplier needs to know what chemicals have been used in the entire supply chain not just make assumptions.

If your supplier tells you that the manure that is on offer has been stacked for a long enough period to ensure all chemicals have dissipated it is likely that they are unaware of the persistence of aminopyralid. Stacking manure will not remove this type of contamination.

If after speaking to your supplier you are in any doubt them don't accept manure.

 

For more information click here For a printer friendly advice sheet click here

 

 

Can Testing the Soil Help?

We are advised to test soil to determine whether or not it is contaminated with herbicide but if it is as easy as that why has it been so difficult for professional testers to determine that aminopyralid is present in manure.

I am not an expert but am just trying to make sense of what I have been told, my experiences and whether to trust testing.

 

• I am told that the aminopyralid is only released into the soil when the plant materials, which has absorbed the herbicide, has decayed.
• The particles of plant material in the manure will break down at different times.
• The rate of decomposition is unpredictable depending on weather and how aerated the soil is. Rotavating and digging helps to aerate the soil.
• The herbicide then breaks down and becomes harmless after a few weeks.
• In our experiences we had tomatoes planted for several weeks before any ill effect were evident.
• We had potato plants growing next to one another where one plant was affected and the other not. I was told that the herbicide will not leach from one area of soil to another. Ultimately a whole bed of potatoes were affected but this happened over a period of time.

 

All the above lead me to feel some degree of sceptism in relation to the effectiveness of testing. In my opinion testing may prove that the manure is contaminated with a herbicide but not prove that it isn't.

 

What if you suspect that you have acquired contaminated manure?

Advice given if you suspect you have applied contaminated manure is:

Check with your supplier

 

If your crops are showing the effect of herbicide poisoning see photos here

• Remove as much manure as possible.
• Don't keep the manure in a pile - if you can have piles removed and disposed of. Soil bacteria are needed to break down the residue and render it harmless to your plants.
• Rotavate and dig the soil as often as you can to speed up decomposition.
• Don't cover the soil as this will prevent air getting to the soil.
• Grow crops that are less likely to be affected - we found courgettes, squashes and sweetcorn grew with no problem. We also had no ill effect as far as our brassicas were concerned.
• Don't compost any affected plant material
• Don't burn any affected plant material - this could be illegal
• If your polytunnel or greenhouse is affected then keep turning the soil and keep the soil moist. Moisture and air are needed to aid plant decomposition.
• Carry out the test described above
• Inform the CRD and DOW giving them information about the problem as they are monitoring the effectiveness of the new stewardship. (They may no longer be interested but contact them anyway)

 

Our Plot one year after the contamination

May 2009

At present no-one on our allotment site has had any sign that the problem is still with us.

We have planted potatoes in soil that was treated last year and these are at present growing well.

We have planted dahlias in the area that was worse affected last year. We also have dahlias in an untreated area and at the moment both sets are sprouting and showing no signs of distress are sprouting. I will update if any signs of contamination is detected.

 

May 24 2009

Volunteer potato plants, from tubers missed when digging up last year, growing in the area of ground badly affected last year are showing signs of distortion. So it would seem that there is still some contamination in the soil. This is the are where we have planted dahlias so we will see what happens to them - I am hoping the problem will be localised but the potato plants that are affected are not close together.

​

 

7 May 2009

I emailed DOW to ask about the above asking if the soil was still contaminated or whether it was something linked to the tubers and today I received this reply.

 

"The way aminopyralid works in plant material, it is very likely the effects you describe are a result of residues being retained in daughter tubers of potatoes grown last year. Is it only these “groundkeepers”, the tubers that were accidentally left in the soil over winter, that are showing symptoms, or are other plants of different species also affected? If it is only the potatoes, I doubt the affects are as a result of manure in the soil still containing aminopyralid.

 

Broadly-speaking, any manure that was dug-in last year, and has been well dug over since, should have had any remaining residue of aminopyralid broken down by soil micro-organisms. This is dependent on the plant material having broken down, allowing the microbes to work directly on the aminopyralid. However, if plant cellulose material is still easily found in the soil there could still be a problem in 2009".

 

One person affected last year has reported:

We are noticing plants still affected in beds that were contaminated last year. This is despite a long fallow period with repeated forking over and raking down to a fine tilth for nearly 12 months now.

 

30 May 2009

Now some potatoes on a neighbouring plot are showing very similar symptoms – just one of the varieties planted – Picasso. The plot holder is new and hasn’t added anything to his soil – only water and the plot was fallow before he used it and no-one dumped any manure onto it.

 

This was a puzzle and so I sent photographs of his potatoes to the RHS and to DOW asking the following.

 

Is it possible that the seed potatoes that he bought had been grown in contaminated manure and the seed potatoes absorbed some of the residue which is causing this problem or could the symptoms be caused by something else. I have attached photos of the affected potatoes taken yesterday.

 

1 June 2009

I received the following response from the RHS:

 

Many thanks for your most interesting email.

 

I think Dow are probably right in that daughter tubers might retain weedkiller, especially as other crops appear to be unaffected.

 

As just one of your neighbour’s spuds is showing symptoms it is almost certainly something that has affected the tuber.  It seems unlikely that the seed crop was grown on land manured with contaminated manure as the mother crop would have been badly injured and the crop scrapped.  Other causes include being stored or chitted in the same environment as hormone weedkillers, including lawn weedkillers, which can have a vapour action.  The pictures seem consistent with weedkiller damage.  To check the soil situation sowing some broad beans in that area would be of interest.  A previous plot holder might have used hormone weedkiller on that area.

 

No herbicide or manure has been used on this plot as the previous plot owner just ploughed over the soil for a couple of years or so and before then it was fallow for years. The plot holder is going to try the broad beans treatment. He did buy his shed from someone who was affected by the contamination last year but surely that is a giant leap!

 

I have checked with the previous shed owner and he didn't store his potatoes or anything else likely to cause a problem in his shed so that route has closed down.

 

Media/website interest

21 May 2009

Problems in the USA click here

 

2 June 2009

Local radio visited us for an update and give me chance to get another warning out to be cautious when buying manure

 

5 June 2009 Extract from - Minutes of the 337th meeting of the Advisory Committee on Pesticides (ACP) held on 12 May 2009

5. Agenda Item 5: Applications for the use of ‘Forefront’ and ‘Runway’ (now known as ‘Mileway’) water in oil emulsion formulations containing 30 g/l aminopyralid and 100 g/l fluroxypyr, as an agricultural herbicide and horticultural/industrial herbicide on grassland and amenity grassland [ACP 7 (337/2009)]

 

 

7 June 2009

Another plot holder affected last year emailed to say, "This year  we didn't use any manure at all on our plot, our spuds are coming on great without it. What we have noticed is, where we planted the potatoes last year (with the Aminopyralid manure) some of the pots still in the ground that we missed when harvesting are regrowing, with the fernlike leaves.That means the contaminated manure is still in the ground so this part of the garden is not being used. I thought it would only be in the ground for a matter of three months or so but I was wrong. I wonder how long it will be in the soil for as at the moment I can only use three quarters of my allotment. If it hasn't gone by the end of this growing season we will be down to using half the allotment next year.

 

Response see comment from DOW 27 May regarding tubers left in the ground see above

 

Hopefully things are not as bad as they seem for this plot holder this year My dahlias (another sensitive plant) which are growing alongside the tubers that we had affected in this way are growing fine at the moment. So hopefully DOW's response was correct.