Wheat prices have collapsed to less than half of their peak value from 12 months ago - and it could prompt Norfolk farmers to change cropping decisions for next year.

Grain was one of the commodities whose value soared following Russia's invasion of Ukraine last February, reaching peaks of more than £350 per tonne in mid-May 2022.

But a combination of political and weather factors have since forced prices back down, currently standing at around £160 ex-farm for July 2023.

Norfolk grain trader Andrew Dewing, of Aylsham-based Dewing Grain, said last year's record highs were driven by fears of shortages amid the threat of summer droughts and poor harvests, while grain was still trapped in Ukrainian ports.

But then Europe's harvest was better than expected, and a political deal released millions of tonnes of Ukrainian grain to be exported through the Black Sea - creating a glut which has "killed the market".

"The price has absolutely collapsed," said Mr Dewing.

"There are a number of factors that we can see with the benefit of hindsight, but which no-one could have predicted at the time."

With a surplus carried over and early indications of a large UK harvest this summer, he said there is "a pretty grim prospect" of prices recovering soon - unless a weather "disaster" hits corn production in the USA.

And Mr Dewing believes that could prompt Norfolk farmers to switch to spring-sown barley crops next season.

"Fertiliser and fuel costs have also come down, so the cost of production should diminish to sub-£200 per tonne," he said.

"But if the prices stay in the doldrums and, looking forward to harvest 2024, you can only get £180 per tonne, why would you grow it if it costs you £200 per tonne?

"If you have got blackgrass problems as well, you might decide to take a break from autumn planting and go into spring crops. So I think for 2024 there will be a big swing from winter wheat to spring barley."