The Soil Association said organic food sales had fallen across all sectors as consumers tightened belts in the economic downturn.
Policy director Peter Melchett said: "This has been a really difficult period for all retail, and organic sales have suffered along with the rest of the economy.
"The report shows a mixed picture as consumers react to the financial crisis. But those consumers who are committed to organic products appear to be staying loyal. This shows the underlying resilience of the organic market, which we believe will grow again once the economy picks up."
The Organic Market Report 2009 showed there had been a sharp fall in sales of certain products including fruit and prepared foodstuffs.
Helen Browning, Soil Association director of food and farming: said: "Organic farms like all businesses face uncertainty and volatility. But there are opportunities.
"These include fruit and arable and in developing genuinely local and regional supply networks. Collaboration will be a key to the success of many farm businesses."
Dynamic growth in sales of organic food at farmers' markets saw an increase of around 18.6 per cent to £23.7m last year.