3 links have been added on this idea.
  1. There are loads of good ways drones could be used in the future, including spotting poachers of endangered animals, looks like this idea turned into reality just in time.

  2. Looks like this can be done now. This article describes the Podder that can fire 2 seeds into the ground per second. I guess you just set it up and it covers the land area required. Amazing.