Question

Why do farmers sometimes use more wasteful methods of irrigation than are available?

Answer 1

There are many different irrigation techniques used by farmers. Most farmer's choose to use a more wasteful method simply due to cost. They usually are forced to choose less costly irrigation techniques to make a profit on their farm.

Answer 2

adding to that, lacking of awareness also can be a reason

Answer 3

thanks @ganeshie8 and @sraone88