An “enormous volume of pesticides” used by farmers is damaging wildlife, leading television presenter and naturalist Chris Packham has warned ahead of a visit to Suffolk.

Mr Packham is visiting Lakenheath Fen this weekend as part of a “bioblitz” campaign to assess wildlife found in 50 spots around the country.

He said farmland birds, butterflies and bees have all suffered significant declines in numbers due to pesticides, while wildflower meadows have largely vanished from the countryside.

He has called for urgent action to reverse the problems, including more incentives and practical schemes for farmers.

Mr Packham said farmers “are very good” at turning around declines in the countryside, but warned not a sufficient number of land managers were undertaking conservation efforts across a broad enough area.

“We need more incentives for them to do that,” he said.

“That means subsidies, it means making sure the schemes we offer them are practical and work, making sure they can actually implement them.

“It’s all very well coming up with ideas for farmers but if they haven’t got the manpower or the time to implement them it’s not going to work.

“We need to make sure our farmers are properly rewarded for their endeavour and not running overdrafts because they haven’t got their grant yet.”

But he also said there was a need to address issues such as pesticides.

“It’s clear the enormous volume of pesticides that we throw at the UK landscape is having a detrimental effect on many things, notably insect populations,” Mr Packham said.

He said insects were being hit by the “extraordinary tonnage of these poisons that we’re throwing on the landscape”, with knock-on impacts for species that feed on them such as birds.

There was a need to get rid of ones which were too toxic to use, he said, pointing to neonicotinoids, now largely banned over links to bee declines.

Serious questions needed to be asked about the “enormous volume” of glyphosate used on the countryside, though he said the weedkiller was useful as part of “no-till” farming which can protect soil quality.

But he said: “Ultimately we need to be working towards a more organic system of farming.

“It’s not about everyone having to be organic, but moving people more in that direction and cutting down their dependence on chemicals, whether it’s fertilisers or pesticides.”

He said farmers were already managing the land more for wildlife “without too much in proper incentives”.

And with the UK formulating its own agricultural policy as a result of leaving the EU, there was an opportunity to provide better incentives which could lead to a far greater uptake by farmers.

A Defra spokeswoman said: “As set out in the 25 Year Environment Plan, we are committed to protecting the environment from the risks of pesticides.

“At the same time, farmers must be able to protect their crops and produce the food that we all eat.

“That is why we support an approach where the use of pesticides is minimised and growers are supported to improve crop husbandry, encourage natural predators and to breed crops that are more pest resistant.”