The post war era saw a huge jump in resource usage, and the discovery of the Haber process resulted in huge agricultural returns, enabling a massive population spike.
The post war era led to the massive population spike, not improved farming. Anyone apart from their honey for more than a week knows that.
It's not so simple. Haber's process increased the population the globe could support by billions. So yes, baby boomers came from post war era, but global availability of food meant that the generations following didn't starve or cap out.