AGRONOMY AND SOILS Soil Calcium: Magnesium Ratios and Lime Recommendations for Cotton

Some crop managers are concerned that re-peated use of dolomite lime, which contains 10 to 15 % Mg, will produce excessively high soil Mg+2 levels relative to Ca+2 and reduce cotton (Gossy-pium hirsutum L.) K+ uptake and yields. Two cotton field experiments were conducted on well-drained soils to determine the short- and long-term effects of lime applications containing Mg. The first test compared the short-term effects of lime with low and high Mg content on soil characteristics and cotton lint yield. This experiment was conducted at Portageville, MO, in 2000 to 2002 on a field with pH salt 4.7 to compare the effectiveness of calcite (calcium carbonate) and dolomite (calcium mag