We managed to feed nearly six billion prior to GMO foods. Most famines were related to political upheaval and intrigue.
http://www.guardian.co.uk/global-development/2013/feb/16/india-rice-farmers-revolution
Once more, for effect.
Lots more here:
http://sri.ciifad.cornell.edu/
Conventionally grown plants on left, SRI plants on right:
lots more great photos and examples at the cornell site.
Hand labor is what Africans do. Americans use their brainpower to make life a bit easier and far more productive.