This was selective breeding of plants in order to take advantage of fossil fuel and mineral fertilizers and industrialization of fossil-fuel-powered machines to produce more food per unit land.

Says so right on the wikipedia dot org web site you showed the link to:

>It was associated with chemical fertilizers, agrochemicals, and controlled water-supply (usually involving irrigation) and newer methods of cultivation, including mechanization.

Bioengineering to convert petroleum products into something people could eat. Really, preventing famine and causing populations to increase are the same thing. A food surplus lets populations grow, a food shortage causes famine.