The website sustainweb.org has an excellent free downloadable booklet highlighting six myths about organic farming. The booklet breaks down each of the myths and gives the facts in detail. Here's an excerpt of just some of the topics discussed:

Myth: Consumers are paying too much for organic food.

Reality: Not so: crop rotations, organic animal feed and welfare standards, the use of good husbandry instead of agri-chemicals, and the preservation of natural habitats all result in organic food costing more to produce. Non-organic food appears to be cheaper but in fact consumers pay for it three times over – first over the counter, second via taxation (to fund agricultural subsidies) and third to remedy the environmental pollution (or disasters like BSE) caused by intensive farming practices.

Myth: Organic farming increases the risk of food poisoning.

Reality: False: organic farming can actually reduce the risk.

Myth: Organic farming uses pesticides that damage the environment.

Reality: Untrue: Organic farming systems rely upon prevention rather than cure, minimising the need for pesticides.

View the entire booklet (PDF)