Here’s an excellent bone(meal) farm design by KaspersMC:
I made a wheat farm that produces the crop at a rate of 75 wheat/minute, made through the use of BUD switches, rapid pulses, and dispensers. The entire thing fits in a very small area and can be made with considerably low resources of redstone.
This design is an improvement on one made by GenerikB, famous for his inventions, and his series ‘redstone wars’, so check him out!
http://youtube.com/GenerikB
World Saves: http://bit.ly/pearsquirrelsaves
Donate: http://bit.ly/pearsquirreldonate
Full-Auto Wheat Farm