My friend Rhona McAdam unwinds the complexities of decreased food production for us at iambic café and notes, in part:
The technology that we depend on now to boost agricultural yields is artificial nitrogen, created through heavy use of oil; an estimated 50% of agricultural costs now are tied to producing fertiliser. The commentator drew one scary comment from an interview subject: since its introduction after WW2 artificial nitrogen has allowed the world’s population to increase unchecked, by boosting yields (with less and less nutritious crops). The global population is such that now we have outstripped the yield that could be generated by natural nitrogen cycles, so we are facing the real possibility of not being able to feed the world even now. Which I guess is why the recent Unesco report on world farming was so firm on the use of organic farming practices, which include natural means of soil enrichment.
Rhona is able to explain much that is complex in a way that I can understand it. This post is highly recommended – short but not very sweet.