The survey of 46,000 English people sampled in the last year estimates that visitors spent more than £17bn in 2010-11.
But the number of visits fell from 2.86 billion in 2009-10 to 2.49 billion last year, the survey which was backed by the Environment Department (Defra) and the Forestry Commission suggests.
More than half the people surveyed said they visited the countryside or open spaces at least once a week.
Trips to farmland, hills and mountains, moorlands and woodlands increased, but fewer visits were made to urban parks and open spaces, the study showed.
The largest number of visits (22 per cent) was still to parks in cities and towns, while 14 per cent of visits were to paths, cycle routes and bridleways.
Forests and woodland, the focus of heated debate earlier this year when the Government put forward proposals to sell off the public forest estate, received 13 per cent of visits, a rise of 11 per cent on the previous year.
Four in 10 English people believe that wildlife has declined in the past decade and two thirds think the natural environment will be in a worse state in 50 years’ time.