High intensity agriculture

From Superstruct Wiki

As much food as possible from as little land as you have.

http://www.spinfarming.com/ http://globalswadeshi.net often has links to high intensity agriculture / permaculture resources.

Caveat: High-density agriculture techniques are much more water intensive. In areas with water shortages, other options may be more suitable. See Dry Farming and other works in the Soil and Health Library.