Fertilizing for Endurance Not Growth

The middle of May marks a shift in our approach towards plant fertility. In the earlier part of the growing season, we are trying to get the plant to grow and move by enhancing photosynthetic potential. We accomplish this by applying Nitrogen, Magnesium, Iron and Phosphorous. Nitrogen, in particular, is a major component in chlorophyll production and the establishment of proteins. By giving the plant more Nitrogen (in combination with Iron, Magnesium, Sulfur, etc.) the plant can produce more chlorophyll and thus build more carbohydrates through photosynthesis. As the weather gets warmer, the plants photosynthetic potential lessens as its respiration rates increase. Effectively, the plant begins a net-negative carbohydrate production cycle. Because Nitrogen makes a plant grow and growing expends carbohydrates, we want the plant to "settle down" during the hot, humid stretches of summer. We "settle" the plant down by restricting N fertility while continuing our PGR programs. Although Nitrogen fertility is reduced in preparation for the summer months, plant fertility does continue. However, the type of fertility is what changes. In the latter spring and throughout the summer, our fertility plan centers on Calcium, Potassium and Micros. Calcium is a strength mineral that plays a major role in cell strength. If cell walls are strong, grass plants can endure more stress. Potassium helps regulate water movement and helps the plant maintain turgor pressure. Turgor pressure allows the plant to stand more vertical and thus absorb traffic better. Micros are essential nutrients that you may liken to vitamins. Put all of these minerals together and you have a fertility program designed to endure. Once we start seeing the cooler temperatures of the fall season, growth and recovery become the objective and Nitrogen is re-introduced to the program.