Josh mentioned that my method of farming looked archaic, mentioned pistons are better. The plan at this point is to use water to flood the crops down to a trough and to use pistons via button/lever or whatever to initiate/stop the floods.
It'll have to be replanted by hand though.
Is this the most efficient farming possible?
They're 6x7 plot terraces with irrigation buried at dirt level 2 away from the flood (behind walls, single water square).