We apply NH₃  with our 41', JD 1610 plow.  Just about everyone around here has a tube that goes off the side of the sweep...we are sweeping while fertilizing.  As far as spacing goes, seems like we have tubes on every shank on the back row, and one or two tubes somewhere's in the front rows...  Moisture must be 'just about perfect', or one can lose a bunch of NH_3.  I like Plowboy's method of chiseling better.  The 1610's shanks are much heavier than a 1600.

 And yeah, the 1610's shanks are just like the 610's.  I have a JD 610, also, and do not like it NEAR as much as the 1610...even though the 610 is "new(er) and improved".  There has been MAJOR rockshaft trouble with these plows!  If a person ever thinks of buying one, make sure it has the solid rockshaft.  I can show you several junk 610 rockshafts around this part of the world. (I have not had trouble (yet), but have neighbors who have had to replace them..)

Plowboy:

So, which do you like better?  The Wiese's or the 2 inch chisels?  When you say 'chisel' are you talking something like a chromium-carbide (c.c.) chisel (BIG triangle point on the end)?  If so, how did you attach the tube to the c.c. chisel?  Did you simply weld it (on the back side?), and have to cut it off, or simply replace it when it is time for a new chisel?  I sometimes put my c.c. chisels on my 1610, and 'mini-rip' things.  My c.c. chisels can also be used in conjunction w/ some 'special' sweeps, that have a notch in them so you can sweep while using the c.c. chisel.  I do not have those 'special' sweeps...just the chisels...Thanks for the advice.