In response to concerns that high yields of alfalfa need to be fertilized with sulfur (S) because of soil depletion of S and less S entering the soil from atmospheric fallout, studies were conducted during 1998-1999, to test for S response by alfalfa. Additionally, alfalfa was tested for magnesium (Mg) response because previous hay analysis from the study site had shown very low levels of Mg.
Wells, Kenneth L. and Dollarhide, James E., "Effect of Magnesium and Sulfur Fertilization of Alfalfa" (2000). Soil Science News and Views. 3.