I got very bored today and figured out an optimal sugar cane farm design. It's basically a rotation based around how a knight moves in chess
So you start with water in the middle, place four sugar canes around it, then make four more water plots such that each sugar cane is touching only one point of water. Essentially:
Code:
S S W S S
W S S S S W
S S S W S S
S W S S S
S S S W S
S W S S
The bolded S show how you get four sugar in a straight line with each sugar only touching one water. The underlined W is sort of the starting point. The patten is: up up left, right right up, down down right, left left down.
Just keep repeating that pattern and you'll need a lot less water (and Lilly pads if you're using them) than if you just alternated water and sugar cane.