The vote means the European Commission’s proposals to ban the use of pesticides on nitrogen-fixing crops, fallow, cover and catch crops can now come into force.

However, exactly how the rules will be implemented and the timetable for their introduction is not yet clear.

Ed Hutley, farm consultant in the St Albans’ office of Strutt & Parker, said: “It is vital that farmers are given clarity on exactly how the rules will be implemented with some urgency.

“People are currently looking at next year’s cropping plans and will need to know if adjustments are necessary to ensure they can meet their 5% EFA requirement when it comes to completing their 2018 Basic Payment Scheme application.

“The majority of our clients use peas or beans to meet their EFA requirements, but without pesticides their viability as break crop will be questionable.

“This means farmers will instead look to maximise any other fallow, buffer strips and hedges to use as EFA.”

Mr Hutley warned that farmers with CSS agreements face the added complication of double funding rules, which prevent farmers from being paid twice for the same activity.

“Farmers with Entry Level Stewardship (ELS) agreements preceding January 2012 were able to use relevant options in their ELS agreements to count towards their greening obligations without any changes to payments.

“However, these five year agreements have now all come to an end and anyone in the new CSS will be affected by the double-funding rules, which mean that if CSS options are used for EFA then the CSS payment is slashed.

“Anyone in, or currently considering, a CSS agreement needs to consider how much hedge and buffer strips the farm has and be prepared to either fallow more areas for EFA or grow catch/cover crops.

“It is not a reason to avoid CSS, but it does need consideration. The answer may well be a catch crop from August to 1 October prior to late sown wheat or winter beans.”

There are five qualifying options that count as EFA – fallow land, buffer strips, catch and cover crops, nitrogen-fixing crops and hedges, although different weighting factors apply for each crop.

The options must be located on arable land, with the exception of hedges and buffer strips, which must be adjacent to, or within five metres of, the arable land.