Correlation between Solvita Labile Amino-Nitrogen and CO₂-Burst Soil Health Tests and Response to Organic Fertilizer in a Turfgrass Soil

ABSTRACT

The Solvita Soil Labile Amino-Nitrogen (SLAN) and Soil CO₂-Burst (SSCB) tests are used in soil health assessments. Field experiments were conducted from 2014–2016 in Connecticut, USA to: (1) determine if SLAN and SSCB concentrations are correlated for a sandy loam soil under predominately Kentucky bluegrass (Poa pratensis L.) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] turfgrass lawns, and (2) compare the response of SSCB–C and SLAN–N concentrations in relation to varying rates of an organic fertilizer. Concentrations of SLAN–N were positively and significantly (P < .001) correlated with concentrations of SSCB–C for all years, both species, and combinations of years and species (r = 0.477 to 0.754). The response of SSCB–C and SLAN–N concentrations to organic fertilizer rates were positively linear and significant (P < .01) in all cases but one (2014 tall fescue SSCB–C concentrations). Rates of change across fertilizer rates were generally greater for SLAN–N concentrations. There was greater variation within the SSCB test than within the SLAN test. The results suggest that the SLAN and SSCB tests are well-correlated and both may be able to provide an estimate of a turfgrass soil’s N mineralization potential.

KEYWORDS:

• Soil labile nitrogen
• soil CO₂ respiration
• organic fertilizer response
• mineralization

Acknowledgments

Suståne all natural 5-2-4 for the study was donated by Rich Hawkes of Suståne Natural Fertilizer, Inc. The authors thank Jeremy LaClair, Patrick McIntosh, Geoffrey Scott Vose, and Stephen Olsen for their assistance during the project, and Dr. Wayne Roper for his helpful comments on the manuscript.

Disclosure statement

Author William F. Brinton is CEO/Chief Science Officer for Woods End Laboratories. This company is the distributor of the SLAN and SSCB tests used and reported in the study. Karl Guillard, the corresponding author, has a research collaboration with Woods End Laboratories where he receives a 25 to 50% discount on the gel probes used in the research. William Brinton’s input was for consultation and review of manuscripts. He had no influence on the reporting of the results or conclusions and could not prevent the reporting or publishing of the results of the study per signed agreement with the University of Connecticut.

Additional information

Funding

The New England Regional Turfgrass Foundation (Project No. 59) and Storrs Agricultural Experiment Station (CONS00881).