Organic fruit and veg don't just contain more nutrients and fewer artificial chemicals, they are grown by a system that uses 26 per cent less energy than conventional farming.

Standards of husbandry are generally much higher than would be the case for conventional farming, with a higher labour input, higher costs and, usually, lower yields.

In the initial years of transition from conventional farming there are losses in crop yields.

It was the first, side-by-side comparison of organic and conventional farming.

The transition from conventional farming to greenhouses have resulted in fewer field crops and a greater amount of the hothouse variety.