Automated farm question

[NateN]

So I'm planning on an automated farm, and I came across this circuit. http://www.youtube.com/watch?v=xsC2xoQi38I

I was wondering if this could be looped forever. I'm extremely new to red stone, any help is nice.

I'm aware of the dispenser delay, and I want a more permanent loop.

[Spamarian]

What I saw in a very quick forward, is that he shows the usage of repeaters.

The point in an automated farm is to make it as much as efficient.

So, you make the pistons to kit the mellon and the mellon the root, so to be transformed into slices of mellons.
If you place the mellons below the dirt(I have tested it), the mellons dont break. As a result you need 2 rows with mellons and 2 rows of pistons..