I know that Schaffert (http://www.schaffert.com/) has their G2 fertilizer opener that attaches in place of one of the closing wheels. It is a walking tandem setup. We tried them on half of our planter last year and so far have not seen any difference between the yield on that side and the side we have Martin's on (mounted in front of the row unit). We also added the spiked wheel as an option. We were worried about having the fertilizer dribbled on top of the slice that the small coulter makes, but like I said we saw no yield difference, even in last year''s dry spring. We put about 100 acres on each row unit, and after a minor redesign update, ours worked very well. At least we won't have to rebuild them as we have to do to each and every Martin every year.
