Here's some straightforward writing about feeding 9 billion from Mark Bittman.
It's not a production challenge, it's a challenge to address and end poverty.
There's a video of the talk Bittman mentions in the article here:
I would have been happy to embed it - but it's on You Tube in bits and pieces - too tricky for me.
Besides, you can watch videos with other luminaries like Fred Kirschenmann and Michael Pollan on the conference site. The link above will take you there.