With the air temperatures beginning to decrease, we are looking to start back up on our greens cultural programs. Deep-tining greens, or venting, is a critical process that is completed every 2-3 weeks to keep the root zone healthy. By improving root zone drainage, and oxygen content, we are allowing the turf to cope with the extreme temperatures of summer in Oklahoma. Once this process is complete, we roll the surface smooth and apply a granular gypsum into the holes. Gypsum is used for two reasons, for the plant to take up and use, and for ammending the soil profile. The first reason is fairly straight forward, the plant needs certain amounts of available calcium for optimum health. The second reason is a little more complex. Applications of calcium are typically used to remove excess amounts of Sodium from the soil. Sodium is used in small amounts by the plant and most of the unused Sodium hangs around in the soil and ties up essential nutrients. The main cause for Sodium buildup is irrigation water. Eventhough we have relatively small levels of Sodium in our water, the large volume that is applied this time of year can quickly lead to excess amounts. Calcium is introduced and the Sodium is knocked off the soil particle along with the tied up nutrients essentially making them plant available. Monthly applications of gypsum are very helpful in maintaining this soil balance and keeping as much of the nutrients in the soil available to the turf.