Can fertilizer “burn” plants?
Yes, if there is an excess of soluble or quick-release fertilizer salts in the root zone. Leaf “burn” is a visible symptom of insufficient water in a plant. Water moves through the root tissues in response to a concentration gradient on the outside of the root and from inside the root tissue. Water moves from a region of low salt concentration to a region of high salt concentration until the concentration on both sides of the root is equal. As water within a plant system is transpired, a higher salt concentration occurs within the root tissue than in the surrounding soil solution. However, if excessive fertilizer salts are in the root zone, water movement into root cells is suppressed. Under extreme conditions, water actually moves from the root tissue into the surrounding soil solution. The movement of water through root tissue is called osmosis. The tendency for a fertilizer to dissolve and release salts when in contact with water is known as the SALT INDEX. The amount of salt releas
