one big potential problem with simply adding magnesium to fertilizers is that its is extremely hydrophilic and will lock to water and become impenetrable. My suspicion is that one of the larger issues that aren't even discussed is the role of fungi in the soil. Usually there is a symbiotic relationship between plants and fungi whereby the fungi breaks down minerals in the soil and hands off these precious ions to the plant in exchange for sugars. By giving readily digestible nutrients to the plants via artificial fertilizers, we rob the fungi of its role. The plants stop working with the fungi and they soon die off. This in turn robs us of nutrients the plant would have attained as a result of the symbiotic relationship. Magnesium being among them.
Cool that you brought up fungi.
It seems to be a very poorly understood field of study. I think it was an accepted part of the ecosystem for ancient farm technologies, however our modern world of compartmentalizing, nutrients, minerals, pests, etc is missing many of the inter locked natural systems. There have been interesting studies in the last 15-20 years revealing more and more about the micro life in soil. The interplay of bacteria, fungus, nutrients, biology and chemistry, can be quite fragile and using mono crops, selected fertilizers, selected pesticides can screw up that ecosystem. Think about old farmers spreading cow shit everywhere in the garden, composting with other animal manure, which all came from animals fed a wide range of food stuffs.
