Richard

Lest it has been lost on newer readers ... this thread is about how the present food supply for the planet can be sustained if and when the present mineral sources are exhausted. Part of the problem is that the planet as a whole has become dependent upon high crop yields per acre made possible by the use of mineral-source fertilizers with chelated micronutrients and soil biotics. Since the amount of available farm land and irrigation water is also reaching its maximum, the needs cannot be met by using less nutrients and more land/water resources. The proposed solution by the fertilizer industry is to make municipal sewage systems their major source of minerals (currently it is a minor source). This is appealing because it captures the nutrients that were used to grow the plants in the first place.

Here is an example why "organic farming" is not viable for the scenario of the world food supply:
One of my colleagues (and client) is operates a small farming concern in the central valley of California. Among other things, he has a 2,000 acre plot of produce grown in a very healthy soil and supplemented with water-soluble fertilizers, plus an adjacent 5,000 acres of the same produce crop but grown according to California Certified Organic standards. On an annual basis, the 5,000 certified organic acreage produces almost half of what the mineral-fed 2,000 acres achieves. His certified organic results are considered exemplary -- especially since his "standard" acreage is some of the most efficient in the industry.
So as you can see, switching from mineral sources to methods and materials used in certified organic farming is not a solution for the current food demand, because 5 times the land and water is not available.

I would be interested to hear of alternatives to the proposed sewage retrieval method. However, please do some homework so that we can all see that it is a viable alternative.

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