After WW II, the Green Revolution increased food productivity until the 80's by using pesticides, fertilizers, mechanized farming and high-yield varieties (HYVs) of crops.

Food productivity increased again at the turn of the century from genetic engineering technologies.

Consequences of these developments include:

Loss of crop biodiversity - many heirloom varieties may be lost.
Runoff of nutrients and loss of soil organisms.
Heavy irrigation drains aquifers and leads to soil salinization - buildup of salt.