The areas down to wheat and winter oilseed rape for harvest this summer both fell by nearly a fifth due to poor winter weather which led to a upsurge in spring barley and oats.
The total wheat area fell 19% to 1.61m hectares, while autumn-sown oilseed rape also fell 19% although the rise in spring rapeseed trimmed the total oilseeds fall to down 9% at 686,000ha.
These two sharp falls depressed the overall British cereal and oilseed rape area which fell 4% to 3.68m hectares, based on an Agriculture and Horticulture Development Board/Home-Grown Cereal Authority intended harvest area survey.
A wet autumn drilling season was largely responsible for the fall in the wheat area, while a big area of winter oilseed rape was ripped up leading to the swing towards spring drilling.
The low wheat area makes it likely that the UK will remain a net importer of wheat for the coming 2013-2014 marketing year as it was in 2012-13, the survey says.
Grain traders estimate a likely wheat harvest of 11.5-12.0m tonnes compared with 13.3m tonnes in 2012 and a record 17.2m tonne crop in 2008.
The wheat crop was seen improving with good growing weather in May and June, although the current heat wave is putting pressure on some wheat crops on lighter land.
All regions saw a fall in the wheat area with the south-west England showing the biggest decline of 26% while eastern England showed a smaller decrease of 12%.
The area down to barley rose 26% to 1.23m hectares driven by a 54% rise in spring barley to an estimated 922,000ha, with extra plantings in England making up most of the increase.
In Scotland, which accounts for a third of the British spring barley area, the harvest area has increased by 5% to 303,000ha.
The total British oats area rose 32% to 159,000ha and the area to field beans increased by 14% to 109,000ha.