Light green alfalfa in the background of the photo was adequate in all nutrients except S which was 0.14% – well below the critical level of 0.25%. Sulfur was 0.26% S in the darker green alfalfa. Although appearance and tissue analysis suggest the alfalfa is ailing from S deficiency, the ultimate criteria is seeing a response to applied S. Leaving a few strips without S or only applying S to several test strips is the best way to determine if this is truly a S deficiency. For more information on S nutrition of alfalfa click here.
Southeast Purdue Agricultural Center. (Photo Credit: Alex Helms)
