Date of Completion


Embargo Period



Dr. Karl Guillard, Thomas Morris, Cristian Schulthess, Jason Henderson

Field of Study

Plant Science


Master of Science

Open Access

Open Access


Nitrogen (N) fertilizer recommendations are very difficult to make for turfgrass because N is transient in the soil and because the N mineralization potential of soil can be difficult to predict. This study was conducted to determine the relationship between turfgrass performance and Solvita® Labile Amino N (SLAN) and Soil CO2-Burst (SSCB) tests. Kentucky bluegrass (Poa pratensis) and tall fescue (Festuca arundinacea) turf plots received 23 rates of organic fertilizer and 4 rates of urea, and were evaluated separately for five measures of turfgrass performance: total foliar N, normalized difference vegetation index, chlorophyll content, grass clippings yield, and N uptake. Solvita® test results were positively correlated with all turfgrass performance measures for both species of turfgrass. Using the urea treatments as benchmark values, binary logistic regression indicated the probability of equaling or exceeding the benchmark values based on the SLAN or SSCB results. Furthermore, the SLAN test is well-correlated with both the Illinois Soil N Test and the SSCB test. The Solvita® soil tests are easy, relatively inexpensive, and can be completed in 24 hours. They have the potential of improving N recommendations for cool-season turfgrass lawns.

Major Advisor

Dr. Karl Guillard