Of course I accept that, however as a farmers son an living in the farming community I am well aware of the fact that UK food crops are becoming less and less marketable. Other countries with lowere labour rates, land costs and lower transport costs are able to produce it much cheaper than the British farmer. This trend is likely to continue since many large countries such as Russia have yet to reach their full potential. I read somewhere that if Russia ever meats its potential, it could supply enough food for most of the developed world, that is a scary prospect as far as farming in the UK is concerned. The consumer in this country unfortunately values price over patriotism or quality in many cases (not all), this has lead to the continual driving down of prices by supermarkets. I'm sure you have seen the ads on tv as I have, price cuts here and there, they have to come from somewhere. Many consumers will say I would like to buy british, but end up buying the cheapest. Due to inherant factors such as land prices, british food will never be cheap. This is where biofuels could come in, whilst I accept that there isn't enough area to keep everyone going, I would argue that some reduction in fossel fuel usage is better than none. The income generated from crops would really help the farming community aswell as the assosiated industries. Farmers may only be 1.5% of the population, but if you take the assosiated industries that are affected by the downturn in income then it could be as high as 20%.
As far as oil seed rape, you are right, there are better crops, but I couldn't think of which ones they were :o)