As noted in a post yesterday, a myriad of nutrient products (Calcium and Magnesium in particular) are being applied to greens this afternoon. While the aerification holes are open, this is an excellent time to work nutrients into the root zone where they need to be. It is still early in the year, so no nitrogen products are being applied at this point. Nitrogen is the key element that trigger grass growth. Too much Nitrogen can be extremely negative and work against our efforts to produce smooth, fast putting greens. I tend to stay away from granular nitrogen sources on putting greens with one application at the most being made annually. All of our nitrogen applications come in the form of liquid sources that are applied in extremely low rates on a weekly basis from April-November. This program is known as "spoon-feeding" greens. It gives me full control of fertility and each week I can adjust what the turf is getting based on our objectives for that week or how the weather is behaving. For example, if I know it will be cloudy with rain for the coming week, I'll most likely with hold any form of Nitrogen.