SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/560546
W hen field managers think about fall fertilization, many assume the focus is on cool-season grasses. While this may be true for many regions of the country, the ABC's of fall fertilization can include some considerations for both warm- and cool- season grasses. The type of fertilizer and application timing has always been and is still important, so using the correct fertilizer at the correct time will maxi- mize growth, recovery and performance; making fall one of the most important time-frames for fertilization. One item that still remains true is the fact that a good fertilization program is dependent on proper soil testing. So as we discuss the ABC's of fall fertilization, we will remind everyone on the importance of testing our soils, look at the various types of products available, and develop a plan with some of the latest research in mind. Soil testing is the basis for develop- ing a fertilization program. While the small investment in a soil test can tell the field manager what is needed; a soil test can also tell a field manager what is NOT needed, saving money. Testing should be conducted annually on sand- based fields and every 2 or 3 years on a soil-based field. Another option in con- junction with soil testing is tissue testing. Here, a field manager can determine the effectiveness of their fertility pro- gram, by seeing if nutrients are actually being taken up by grasses in sufficient amounts. The following table has been an excellent resource for understanding the role that each nutrient plays in the growth of a plant and the amount of nutrients required for that growth. A helpful conversion for this table and soil testing reports to convert ppm to pounds/acre is to take ppm times 2 to equal pounds/acre. Refer to "Understanding Soil Tests" at STMA. org for interpreting a soil test report and managing soil pH. We also need to remember that soil pH plays a role in nutrient availability; therefore pH results are as equally important to knowing nutrient levels. Kentucky bluegrass and bermudagrass grow best when soil pH is between 6.0 and 7.0; tall fescue pre- fers a soil pH from 5.5 to 6.5. Perennial ryegrass can tolerate a wide range of pH (5.1 to 8.4); however it performs best with a soil pH of 6.5. Your local Extension Office or soil-testing lab will usually provide rec- ommendations based on your particular location and soil type. It is also important to indicate on the submission form that your soil sample is for turfgrasses so appro- priate recommendations can be made. 16 SportsTurf | September 2015 www.sportsturfonline.com THE ABC'S OF FALL FERTILIZATION FIELD SCIENCE Blended fertilizers can be blends of quick (white prill) and controlled-released (blue prill) nitrogen sources including a phosphorus (brown prill) and potash (rose prill) component. Photo: Brad S. Fresenburg. ■ BY BRAD FRESENBURG, PHD CALCULATING THE AMOUNT OF FERTILIZER NEEDED Take the amount of N, P 2 O 5 , or K 2 O needed per 1000 sq ft divided by the percentage of that respective nutrient as a decimal (e.g. – 24% N = 0.24) to equal lbs of fertilizer product required per 1,000 sq ft.