Linkages between extracellular enzyme activities and the carbon and nitrogen content of grassland soils

Valeria L. Cenini, Dario A. Fornara*, Geoffrey McMullan, Nigel Ternan, Rachael Carolan, Michael J. Crawley, Jean Christophe Clément, Sandra Lavorel

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)

Abstract

Important biochemical reactions in soils are catalyzed by extracellular enzymes, which are synthesized by microbes and plant roots. Although enzyme activities can significantly affect the decomposition of soil organic matter and thus influence the storage and cycling of carbon (C) and nitrogen (N), it is not clear how enzyme activities relate to changes in the C and N content of different grassland soils. Here we address whether the activity of C-acquiring (β-1,4-glucosidase, BG) and N-acquiring (l-leucine aminopeptidase (LAP) and β-1,4-N-acetyl-glucosaminidase (NAG)) enzymes is linked to changes in the C and N content of a variety of human-managed grassland soils. We selected soils which have a well-documented management history going back at least 19 years in relation to changes in land use (grazing, mowing, ploughing), nutrient fertilization and lime (CaCO3) applications. Overall we found a positive relationship between BG activity and soil C content as well as between LAP + NAG activity and soil N. These positive relationships occurred across grasslands with very different soil pH and management history but not in intensively managed grasslands where increases in soil bulk density (i.e. high soil compaction) negatively affected enzyme activity. We also found evidence that chronic nutrient fertilization contributed to increases in soil C content and this was associated with a significant increase in BG activity when compared to unfertilized soils. Our study suggests that while the activities of C- and N-acquiring soil enzymes are positively related to soil C and N content, these activities respond significantly to changes in management (i.e. soil compaction and nutrient fertilization). In particular, the link between BG activity and the C content of long-term fertilized soils deserves further investigation if we wish to improve our understanding of the C sequestration potential of human-managed grassland soils.

Original languageEnglish
Pages (from-to)198-206
Number of pages9
JournalSoil Biology and Biochemistry
Volume96
Early online date03 Mar 2016
DOIs
Publication statusPublished - 01 May 2016
Externally publishedYes

Keywords

  • Extracellular enzymes
  • Land use
  • Lime
  • Nutrient fertilization
  • PH
  • β-1,4-Glucosidase

ASJC Scopus subject areas

  • Soil Science
  • Microbiology

Fingerprint Dive into the research topics of 'Linkages between extracellular enzyme activities and the carbon and nitrogen content of grassland soils'. Together they form a unique fingerprint.

Cite this