What harmful chemicals are there in organic farming?

Farming: What are good ways to kill all vegetation on land? Which chemicals to be used to make it completely barren?

• How do you annihilate all vegetation on a big big piece of land. Not just weeds but every vegetation, everything that is green and grows. This land will be used by airport authorities so it will never have any vegetation for a long time. Even if it is to be done at the cost of land erosion. Even salting is an option. Which is the best way to achieve it quickly and efficiently, cost wise and labor wise?

• Answer:

  Salt. It's cheap, can be applied as a solution (water + salt) and will eventually wear off. You would then have to reapply the salt. However, the cost of the salt and the labor to apply it is low enough that it is still economical. Monsanto's "Round-Up" is a salt but it is much more expensive than Halite.