I watched A Farm for the Future last night (part of the BBC Natural World series) which looked at UK agriculture and its dependence on fossil fuels. Although there wasn't much new information it was a very good summary of the problems that we will face as the supply of oil runs out.
One thing I hadn't realised was the damage done to soil by ploughing year after year. Although land has been ploughed for thousands of years the damage has only occurred on a large scale as mechanisation has increased, more efficient ploughing means more efficient destruction of the soil wildlife and bacteria as the soil is turned and exposed to light and air. I was struck by a film of a tractor ploughing around thirty years ago when it was followed by flocks of birds picking up worms and insects and another film of ploughing taking place today, no birds follow the tractors now because there is so little life in the soil. I remember seeing seagulls following tractors when I was small, but I hadn't really noticed that it didn't happen any more. How sad, and bad news for food production too.
I was thinking about the program when I was out for a walk this afternoon, lots of the fields were freshly ploughed.
The program was not all doom and gloom though and there were some good examples of working with nature instead of against it such as very productive forest gardens producing huge crops from a small space. It makes me want to cram even more into my small garden.