We must be forever mindful that any food production that degrades soils now will eventually take food from our descendants. But there is hope. With the maturity of ecology and evolutionary biology, both disciplines are available to merge with agriculture and assist in truly sustainable food production. No other material or industrial process can entertain such a hope. If we don't get sustainability in agriculture first, sustainability will not happen.
Soils are the key.
It is clear that agricultural civilizations have depended on an abundance of soils. And without the later subsidy of fossil fuels, in combination with our soils, the scientific revolution would have stalled. It seems likely that there would be no knowledge of DNA, no Einstein equations, no space age, no Hubble telescope, no knowledge of tectonic plates and continental drift, no knowledge of geologic or cosmic time, no expansion of our knowledge of the scale of the universe or the inner recesses of the atom. All of those accouterments of civilization have rested on soil, which is as much a non-renewable resource as oil. We are the only species, in this part of the universe at least, that knows that we are made of stardust recycled through supernova.