by Bruce Darrell, from Fleeing Vesuvius. This paper describes practices for ensuring that we can continue to feed ourselves adequately in the future, with a focus on the need to ensure that the soil contains an optimal mix of nutrients. Very few soils have a perfect balance of minerals. As a result, their fertility is limited and the crops grown on them cannot provide all the nutrients people need. As people can get food from elsewhere at present, these local deficiencies do not matter too much. But this situation is likely to change.