Environment Agency data shows that Bentazone (the herbicide active substance in Benta and other products) is the most commonly detected approved pesticide in UK groundwater. It’s also increasingly being found in surface water. Due to EU legislation on pesticides and water, it is possible that the approval for Bentazone will not be renewed, resulting in the loss of all Bentazone products.
‘Know The Bentazone Risk’ is a cross-industry programme, aimed at promoting sustainable water stewardship on farms. It includes events, on-farm engagement and the development of management tools, including the new Crop Planning and Bentazone IPM Tool.
Check Your Risk Use the quick and easy mapping and planning tool to see if your farm is in a high-risk area or has vulnerable soils.
Following use of the risk mapping tool by growers since its launch in 2021, feedback has helped improve the tool for 2025. Updates include:
- A simplified interface
- More IPM guidance
- Features to evidence decisions taken
The use of this Crop Planning and Bentazone IPM Tool has been developed to support water stewardship initiatives while promoting responsible and sustainable product use.
For maximum value, the tool should be used during rotation planning to avoid sowing legume crops on the most at-risk fields and hence avoid the use of Bentazone.
Bentazone is highly soluble in water and very mobile in soil which has resulted in it being detected in both ground and surface water.
It’s also worth checking in-season before spraying Bentazone.
Check your Bentazone risk here
Know The Bentazone Risk
Why does it matter?
Sustainability and stewardship are important to Nufarm. As part of a cross industry initiative, we aim to provide guidance on Bentazone stewardship to keep ground water and surface water clean.
Data from the Environment Agency has shown that bentazone (Nufarm’s Benta) is the approved pesticide in UK most frequently found in groundwater and is also increasingly being found in surface water. Due to the link between EU legislation on pesticides and water, it is possible that the EU approval for bentazone will not be renewed, resulting in the loss of all bentazone products across Europe.
For other stewardship advice such as phenoxy herbicides, see our phenoxy stewardship page.
Thankfully it is possible to minimse field sources and avoid farmyard source all together.
Bentazone VI sheet
The Voluntary Initiative has put together guidance on when and where to spray bentazone.
Environmental Agency water protected areas
The Environmental Agency has created a map in which you can check water risk in your area.
Contact our technical team
Dick Dyason – Technical Manager
+44 7766 113373
[email protected]
Voluntary Initiative
The VI website has up to date guidance on stewardship and best practice.
View our Spraywise series.
A comprehensive program covering best spraying practice.
7 part video series.
What must we do?
As we mentioned above, it is possible through best practice both in the farmyard and in field to minimise and avoid pesticide residues. By being aware of the soil type you are spraying on and acting accordingly as per the Voluntary Initiatives guidance. Other factors such as taking care if heavy rainfall is due, avoiding application when drains are heavily flowing, reducing dose rates and leaving application as late as possible (NOT in Autumn/Winter).
When on the farm, having a selection of designated areas and contingencies can counter the risk of spillage and residues when washing. In field there are many measures that can be taken to maximise efficacy of sprays.
Our Spraywise series takes viewers through an extensive guide on water stewardship when spraying and storing crop protection products. The seven part series takes you from stores and management of products safely to filling up sprayers through to washing out in field.
Having a system for decontaminating spillages and wash outs is a great tool for a grower to have. These Biobeds/Biofilters work as a mitigation measure for water in the filling area contaminated with residues. Pumped from the bunded area, the contaminated water is filtered through at least 3 filters made from organic material, usually soil and/or chopped straw.
Using a Biofilter to avoid contamination
Here is John Martin explaining his biofilter system, he also takes the time to explain some top tips to make setting up a biofilter easier:
Any further enquiries don’t hesitate to use our technical helpine: +44 1274 691234
Have a technical question? We’re here to help.
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