It has been reported that the treated area (1.5 tons/A) of PRO CAL 40 was 30 bushels/A better than the untreated area. This field is in the Missouri River valley and has a CEC of about 28 and 27% Mg (gumbo soil). There was also a poorly drained soybean field that was treated with PRO CAL 40 two years ago that yieled 67 bushels/A. The best this field had previously done was around 45 bushels/A.