There is increasing discusion of the sustainability of farming. Of how we can maintain productivity and how we can physically feed all thos eextra mouths that are expected in the coming decade(s). But little or no mention of the degradation of minerals.
With modern farming the product/crop is always removed from the field. With the crop goes a proprtion, however small, of whatever trace elements are in the soil. To keep crops going we put back fertilizer, but this is not aimed at replacing all that has been taken by the crop but only sufficient (and at the lowest cost) to make the crop grow again.
This years crop of wheat is fundamentally different to the crop from the same field 50 years ago. Add to this the genetic engineering / breeding to ensure the crop looks right and is ‘fat’ in this sense lots of carbohydrate. Its also increasingly the same as the crop from a field 100 miles away.
In the case of wheat. We eat it in bread, our food animals eat it, we eat them. We are moving towards a monotonous unhealthy diet denuded of trace elements. But, the standardized crop suites the food seller. Their job is not to provide a healthy product but something people buy and makes money for them. Take out the trace elements and our thyroid doesn’t work, other parts also start to fail, we head towards being malnourished with growing obesity and failing health while surrounded by food.
In the case of salt, we have processed what was a super food with 80 and more vital minerals into just sodium chloride. Okay, its white, tastes like salt, is cheap, pours but is no longer food.
So, not only must we look to maintaining the volume of food, but that it remains food in the real sense.
There are many ways of doing this, only one is becoming increasingly used though it is very unpopular. That is the use of sewage, clearly a sustainable way of dealing with our own personal output and far more sensible than dumping it at sea or burining it. Where I live, this is an annual event, smelly but not that bad. Certainly good for the local fields that are otherwise turning into a desert.
Alternatives exist, the simplest being to physically extract or mine the minerals and dump them on the fields, perhaps as rock dust. Natural processes will then revitalise the fields, however I would expect that is far from that simple.