During the period 1969-71, a test at 33 on-farm locations was conducted in North Carolina to measure the effects of potassium and magnesium at three rates on the yield and quality of flue-cured tobacco. There was no effort to select locations with specific soil types with specific levels of nutrients. The rates of potassium (K₂O) used were 100, 150 and 200 Ibs. per acre and the rates of magnesium (MgO) used were 0, 20 and 40 Ibs. per acre. There was no significant response to the rates of potassium and magnesium used in this study. The regression of relative yield and price against potassium and magnesium fertilization rates was also not significant. This indicated that on soils with the potassium and magnesium soil test levels encountered in this study no response is probable to potassium above 100 Ibs. per acre or to the application of any soluble magnesium in the preplant fertilizer.

(Full article published with kind permission from "Tobacco International")