One of the strong points of the Curvetine design is that two Curvetines per row can be used in a wide range of tillage systems from hard no till ground to right behind a field cultivator.

However you DO need to pay attention to the tailpiece spring pressure, especially on John Deere planters.

Curvetines do not disturb the seed unless they have too much pressure on them for the conditions.

The standard JD tailpiece spring, common from the 7200 up through the current models, is too heavy, even in the lightest spring setting for use with two Curvetines per row in freshly worked ground.  Deere has recently  added a "half rate" tailpiece spring available through JD parts departments. If you have significant amounts of worked ground I recommend changing to the lighter spring.

Or run one 13" Curvetine and one standard 12" rubber per row. this is not ideal in tough conditions as the 1/2" radial difference is not really enough in some tough conditions and the rubber ends up holding the Curvetine up from where we would really like it to run closing the bottom of the slot. But one of each is usually better than 2 rubber tires.

Or you can just run the std JD spring in the disengaged position for occasional use in worked ground. Kinze and White do not require any spring change for two Curvetines in worked ground. Their lightest spring setting is lighter than JD.

A key point to keep in mind is that not all "spike" closing wheels are the same. They each have differences in their mode of operation.

Jim at Dawn