A drive to create more on-farm green energy provided the biggest opportunity for a generation, said farmers' leader Gwyn Jones.

'We should not underestimate the opportunities that bio-energy presents: that is the biggest opportunity to diversify for a generation,' he told members of Norwich and Loddon branch of the National Farmers' Union.

'I believe that also, if we get it right, it will not affect the supply of food and food prices: it will enable farmers to have other income streams and add to the target that the government is so desperately keen for us to reach, said Mr Jones, vice-president of the NFU.

Mr Jones said that, on his farm in Sussex, he had cut his bought-in fossil fertiliser use by half since installing an anaerobic digestion (AD) plant.

'We're growing feedstock for it and we're growing it in land that hasn't grown anything for 10 years,' he said. 'It is marginal land, black sand. With the compost from the AD plant, it grows very good crops of maize. Then, we spread the dirty water on all the grassland; and we've cut the amount of bought-in fertiliser by half. So, it is a win-win.

'It is a profit centre, contributing green energy, and it is cutting down our use of chemical fertiliser, which is an environmental win.

'The local people are very supportive.'

Mr Jones recognised that farming faced major challenges because of soaring commodity prices, especially for livestock producers with dairy, pigs, egg and poultry. 'The contract issue and supply chain issues are the ones that flow through all of this. There's a common theme: it is about price to a degree, but it is not all about price because it is more about risk especially with volatile markets.

'It is about how we make sure that the risk is more equitably shared, and also how we try and get longer-term relationships so people don't just think about today and tomorrow. We've seen that volatility is likely to get worse, certainly in the short term,' he said.

Mr Jones welcomed the decision to appoint a supermarket adjudicator or ombudsman but said the post had to have the powers to investigate market abuses.

'We would like to see not only an active adjudicator looking for areas of problems in the market, but we'd also like the adjudicator to be able to take third-party evidence. The NFU has huge amounts of evidence, which all has to be confidential because of the nervousness of people who are vulnerable should it be broadcast.'

And he emphasised that only about a tenth of the food expenditure actually came back to the farm gate.

'It is a difficult message to tell people that food is going to be more expensive but I think it is a fact of life.

'But price rises could be mitigated to a greater extent by cutting the enormous waste, which is about 30 to 40pc,' he added.

michael.pollitt@archant.co.uk