Yes, many parts of good fertile soils near to cities are covering with industries and the the fact remains valid till breakthrough   happened - that NO MACHINE CAN MAKE A SINGLE GRAIN OF FOOD.  Every Policy maker need to realise this. However, there is more need of good agriculture that use and recycle the natural resources, not harm soil/environment by chemicals, minimise losses of agri-produce in storage/transportation, no use of land for bio fuel crops and no use of grain for raising animals for meat.If we would do this type of good agriculture  that need minimum investment but maximum dedication then our food security will never be threatened.