Question on Loops for Turtles

[GrantTheWizard]

Hello, I am new to LUA but not in programming. I am not understanding why my blockchain is not working.

It is supposed to go 40 blocks down the row(Hence the for loop for count 40)

Then when it gets to 40 come back(I need to change the 3 to a 2) but what it does right now is it digs the first wheat then stays there, then executes the turn then stops. Any ideas on how to fix?