The Government needs to set a target for reducing the use of fossil fuel-based artificial fertilisers on farms or risk missing its net-zero climate goal, campaigners have said.

The Soil Association said it was “alarming” that the Government had “no plan” to reduce the amount of artificial nitrogen fertiliser used and was calling for measures to support farmers moving to “more nature-friendly approaches”.

Manufactured nitrogen fertilisers are commonly used across the UK to provide crops with nutrients, but manufacturing them is energy intensive and the Soil Association says the process almost always requires natural gas.

The charity’s head of farming policy Gareth Morgan said: “It is shocking that the Government’s net-zero strategy makes only a passing mention of the impact of fossil fuel-based fertilisers on the climate and environment and even more alarming that they have no plan in place to support farmers to reduce their reliance on them.

“The production of nitrogen fertiliser is highly dependent on expensive and polluting fossil fuels, making farmers very vulnerable to huge price spikes and global events like the Russian invasion of Ukraine.

“Agriculture and the food system are responsible for a third of all greenhouse gas emissions and failing to address this will mean that the Government has simply no prospect of meeting its net-zero target.

“It is vital that the Government demonstrates its commitment to net zero by setting a target for reducing fossil fuel-based fertiliser in UK farming and offers incentives and advice to support farmers to reduce their dependence on nitrogen fertiliser and adopt cheaper more nature friendly approaches to fix nitrogen on their farms.”

Nitrogen is an abundant gas in the atmosphere, but when exposed to soil in its active form, such as when used in fertiliser, microbial reactions release nitrous oxide, which is a long-life and potent greenhouse gas with nearly 300 times the warming effect of carbon dioxide.

The Soil Association said that in 2019, agricultural emissions contributed 25 per cent of the particulate pollution in London’s air, 32 per cent in Birmingham and 38 per cent in Leicester.

Ecological damage can also be caused if the nitrogen in the fertiliser finds its way into nearby waterways, where it can cause algal blooms that deprive other plants and animals of light and oxygen.

Mr Morgan said he acknowledged farmers in the UK could not “simply go cold turkey on nitrogen”, but said methods from the organic farming sector where artificial fertilisers were not used could help reduce their reliance on the manufactured substances.

The Soil Association said a survey it commissioned on the views of people in Britain found 62 per cent of people wanted the Government and political parties to prioritise policies which addressed climate change, but just 33 per cent were aware of the environmental damage that could be caused by artificial fertiliser.

The charity has set up a petition calling on the public to support its call for action reducing the use of fossil fuel-based nitrogen fertiliser.

The National Farmers Union combinable crops board chair Matt Culley said: “Manufactured fertiliser is a vital product to help grow the nation’s food and is absolutely crucial in supporting the yield and quality of crops, especially on less fertile soils that British farmers and growers require to deliver global and domestic food security.”

He added that: “Farmers and growers use fertiliser responsibly,” and “manure is not evenly distributed across the nation, nor available in sufficient quantities to replace manufactured fertiliser.”

Mr Culley said the farming industry acknowledges it has a big part to play in reducing emissions further, saying it is “already working hard towards this goal” and “fertiliser use has become increasingly efficient in recent years”.

He added: “We will continue to drive forward fertiliser efficiency and improvements around productivity with an aim to reach net zero by 2040, while our farming businesses will continue to provide a good domestic supply of food.”

A spokesperson for Defra said: “We are committed to supporting farmers and land managers to reduce agricultural emissions across the sector to help the UK achieve net zero and safeguard food security.

“We are already promoting the use of more sustainable fertilisers through our new farming schemes and capital grants, investing in storage, innovation and management techniques.

“This includes our sustainable farming incentive (SFI) which will pay for actions that support positive nutrient management, which will improve soil quality and reduce the need for chemical fertilisers.”