Question

What process was necessary to grow crops on a regular basis in   Mesopotamia

Answer 1

The first people to grow plants had to learn three main tasks: how to concentrate desirable plants into a manageable area; how to prevent weeds from growing there; and how best to encourage the plants to flourish. In short, people learned to plant, weed, and water or drain crops.
That's what my book says ;)

Answer 2

people woudl need irrigation