I'm trying to find out whether any research/trials have been done on the cost-effectiveness of organic gardening (in the home garden preferably), as compared to buying vegetables. This is for a polytech research project, and so far I've found plenty of information on organic gardening but none on the costs. Any advice would be greatly appreciated.
Some indication on prices and premiums are in the Nic Lampkin Book 'Organic Farming', but this is a bit old now and mainly European info. Although the principles and ranges still apply, usually certified organic food retails about 10-30% dearer than comparable conventional.
Prices can vary significantly from retailer to retailer. Some supermarkets are very expensive, some of the health food/organic shops are sometimes even cheaper than the conventional lines in a supermarket. Processed organic food seems to have a higher premium because too many middle' people' charge premiums everytime a product is changing hands.
I am not aware of any New Zealand figures published.