Manure matters, so dig a little deeper!

Recently, we have heard from gardeners and allotment holders who have been concerned about possible herbicide residues in the manure and composts they apply to their soil. The active ingredient involved is called aminopyralid.

There have been a few incidences involving alleged damage to sensitive crops that have been reported here in the UK. The manure possibly came from farm animals or horses fed pasture or conserved forage from grassland previously treated with aminopyralid - an active ingredient found in the products Forefront, Pharaoh or Banish. This manure has unfortunately been supplied to a small number of gardeners and allotment holders and resulted in damage to some sensitive crops.

Manure, from horses or farm livestock, is a wonderful soil conditioner and natural fertiliser, and we do not want gardeners and allotment holders to be afraid of using it. This is why we have created the manurematters website - to provide guidance and advice for its future use.

Please select the most appropriate link on the left to find out how this issue may affect you, and how to minimise the chance of any problem occurring.

What is Dow AgroSciences doing?

At Dow AgroSciences we have

  • Voluntarily suspended sales of aminopyralid products until we and the Pesticides Safety Directorate (PSD) are satisfied that all is being done to negate these sorts of incidents happening again.
  • Collaborated with a number of organisations to improve the stewardship of aminopyralid herbicides.
  • We have put an information campaign in place to ensure that everyone involved is aware of the potential problem with manure coming from animals fed forage that has been treated.

Is aminopyralid dangerous?

No. The Pesticide Safety Directorate, the Government agency responsible for the approval of pesticides in the UK concludes that there are no ill effects to human and animal health from food grown from land that may contain aminopyralid residues.

Weed killers or killer weeds?

Aminopyralid-based herbicides were developed to help grassland farmers control and eliminate a number of troublesome and potentially dangerous perennial broad-leaved weeds from their fields.

Although some people are worried about the use of herbicides, the weeds they eliminate are also a concern. According to the Department for Environment, Food, and Rural Affairs (DEFRA) the Weeds Act of 1959 mandates the control of five 'injurious weeds' that threaten grassland health:

  • Common Ragwort
  • Spear Thistle
  • Creeping or Field Thistle
  • Broad leaved Dock
  • Curled Dock

Of these five weeds, ragwort and dock also pose a potential threat to livestock (especially horses), as do buttercups, all of which are effectively controlled by aminopyralid.

What is the chance that I have bought or supplied manure affected by aminopyralid?

Rather slim. Of the 12 million hectares of grassland in the UK, only 5% is treated with herbicide each year. Of that small percentage, less than one third of that area will receive a treatment containing aminopyralid.

Very few incidents of garden or allotment crop damage have been reported, to which Dow AgroSciences and the PSD responded immediately with further testing of the product.

Aminopyralid has passed Plant Protection Regulations stringent approval requirements.

Aminopyralid Fast Facts

The following are general facts about aminopyralid-based herbicides, such as Forefront, Pharaoh, and Banish. For more detailed information about your particular area of interest, click on the most relevant link on the left.

Aminopyralid is safe for humans and animals.

  • Vegetables grown with affected manure are safe to eat.
  • Milk from cows fed treated silage is safe to drink.

Only a few species of plants are affected

  • Sensitive crops include peas, beans, potatoes, sugarbeet, carrots, tomatoes, lettuce and spinach.
  • Affected manure is safe for use on lawns and grassed areas.
  • Affected manure is safe for cereal crops and maize.

Aminopyralid breaks down in the soil

  • Treated fields are aminopyralid-free after one year.
  • Residues in manure break down if rotovated into the soil and turned frequently. But do not use where sensitive crops are to be grown. (See list above.)

Contact us

If you believe your manure has been affected or you have further questions, email us at