Some crops can require as much as 10 calories of petrochemical energy to get 1 calorie of food energy when one takes such things into account --- corn (well, ma

Some crops can require as much as 10 calories of petrochemical energy to get 1 calorie of food energy when one takes such things into account --- corn (well, maize) is quite calorie dense/efficient in terms of land and other usages --- I'd be curious to see a full, comprehensive crunching of the values involved.