Gulf Coast GCSAA Presentation on MLSN

December 15, 2012

Dr. Larry Stowell presented the new concept of Minimum Levels for Sustainable Nutrition to the Gulf Coast Golf Course Superintendent’s Association via webcast on December 11, 2012. The attached pdf file provides an edited version of the presentation that includes information requested during the question and answer period. The key change was the inclusion of information on nutrient requirements for bermudagrass that is overseeded with ryegrass compared to non-overseeded bermudagrass.

Here are some bottom-line tips on fertilization to target soil MLSN guidelines:

• Apply maintenance applications nitrogen (N), phosphrous (P) and potassium (K) in a ratio of 10:1:4 (N:P:K). To prevent leaching and runoff, never apply more than 0.5 lbs N/1000 sq ft in a single application. Lower rates of application and shorter frerquencies are recommended. Adjust nitrogen rates to produce turfgrass performance that grows and recovers adequately to meet golfer expectations.
• Test soils in the spring and fall and compare soil test results to MLSN guidelines
• If soil tests report nutrient levels lower than listed in the MLSN guidelines, increase the ratio of P and K in the maintenance fertilizer applications. For example change to a 6:1:4 (N:P:K) ratio. If nutrients other than P and K are low, for example calcium or magnesium are lower than MLSN guidelines, supply these nutrients as needed to adjust soil levels to exceed MLSN guidelines. Application of 1 lb element/1000 sq ft (about 5 g element/m²) will increase soil levels by about 20 ppm per application.

Stowell, L. Minimum Levels for Sustainable Nutrition. Golf Coast GCSA Meeting Dec. 11, 2012