Switching food production in the UK to organic would mean major reductions in output - but not as big as some might think, claims a new report.

In fact the study, carried out by Reading University's Centre for Agricultural Strategy for the organic Soil Association suggests such a move would cause a shift in "the commodity mix" and as a result lead to people eating more healthily.

The Soil Association says the findings show that organic farming has much to offer and could be "mainstream agriculture in waiting".

Key benefits of a switch to organic farming methods claimed by the report include:

* Cuts in greenhouse gas emissions and water pollution A fall in energy intensive inputs to farming would fall, with fertilizer inputs cut by 95% and sprays by 98%

* Jobs in the countryside would increase, including a 73% increase in farm employment

* As organic fruit and vegetable yields compare favourably with conventional agriculture, organic farming could, with some adjustment, supply similar volumes as at present, or even increase output if necessary

* Due to the need to abolish intensive pig and poultry systems in organic agriculture, chicken, egg and pig meat production would fall to roughly a quarter of current levels, making large quantities of grain available for human consumption

The report concedes that dairy production would fall by around 30%-40%, unless herds were to be re-established and dairies were to re-open in parts of the country which have lost them.

And it says the amount of wheat and barley produced would fall by around 30% due to lower yields but because far less grain would be fed to animals there could be as much wheat and barley available for human consumption under an organic system as there is at present.

"A wholly organic agriculture could actually produce more beef and lamb than at present, with beef production rising by 68% and lamb by 55%," says the report.

Soil Association policy director Peter Melchett concedes that ?organic farming "does not have all the answers to the challenges of climate change and diet related ill-health" and admits there is "still a lot of work to do to improve organic systems".

But he claims the report, England and Wales under organic agriculture: how much food could be produced? shows the positive impact that organic farming could have.

"In the face of the rising prices and scarcity of key fossil fuel and mineral inputs, and the need to cut greenhouse gas emissions 80% by 2050, food and farming systems will have to go through revolutionary changes in the next few decades," says Lord Melchett.

"The rapidly escalating diet related health crisis means that our diets are also going to have to change dramatically. This independent report shows that organic farming could provide us with a far healthier and much more climate friendly diet."