Starter sugarcane farm

A compact lossless sugarcane farm by Forger. Nineteen plants on sand in a glass box, an observer on each one firing a piston as it grows, and a single hopper minecart running one rail line underneath to catch every drop and unload into two chests. Nothing is destroyed on the way out, which is what separates it from the cheaper fence and water designs, and it stacks straight upward with the same list repeated per layer. Small, honest and about four minutes to build.

The hopper minecart unloader does not work on Bedrock. Forger answers this eight separate times: take the unloader out and put extra hoppers along the line instead. Everything else in the build works there.
Angelosanto fixed a cart that deposited only one or two canes before rolling on by extending the powered rail one block past the hopper.
WilliamAftontheChildMurderer lost three hours to a dead minecart before finding the missing block behind the first powered rail.
The demonstration is sped up. Forger raised the random tick speed to film it and says plainly that sugarcane is slow in a normal world, which is what several people report as the farm not working.
lucasjohnson2119 points out you can use ordinary rails in place of powered ones if gold is short.
Carmen-ks19 confirms Bedrock and adds that the whole thing can be mirrored so the pistons sit on the opposite side.