This is a fully automatic sugar cane farm. It is very efficient .
Step 1: Place Down 16 Blocks of Sand in a Straight Line
Step 2: Place Water at the Sides of the Sand Line.Then Surround the Water With a Block of Your Choice.
Step 3: Place Down Your Sugar Cane
Step 4: Place Down Pistons and the Observer Blocks
Place these one block back and up from the first sugar cane.