TY - JOUR
T1 - Ratios between estimates of microbial biomass content and microbial activity in soils
AU - Dilly, O.
AU - Munch, J. C.
N1 - Funding Information:
Acknowledgements The authors thank Mrs. Elke Erlebach, Friederike Schütze, Jörn Sprenger, and Mirsad Haskovic for excellent technical assistance; Dr. P. Weppen, the research group of Dr. O. Heinemeyer, and Dr. E.-A. Kaiser for the use of laboratory facilities; Mr. Lars Theesen for statistical support; Dr. R. Martens and Dr. T.-H. Anderson for helpful discussions. These studies were supported by the German Ministry of Education, Science, Research and Technology (BMBF), project no. 0339077E, and the state of Schleswig-Holstein.
PY - 1998/9
Y1 - 1998/9
N2 - The content levels and activities of the microbiota were estimated in topsoils and in one soil profile at agricultural and forest sites of the Bornhoved Lake district in northern Germany. Discrepancies between data achieved by fumigation-extraction (FE) and substrate-induced respiration (SIR), both used for the quantification of microbial biomass, were attributed to the composition of the microbial populations in the soils. In the topsoils, the active, glucose-responsive (SIR) versus the total, Chloroform-sensitive microbial (FE) biomass decreased in the order; field maize monoculture (field-MM)>field crop rotation (field-CR) and dry grassland>beech forest. This ratio decreased within the soil profile of the beech forest from the litter horizon down to the topsoil. Differences between microbial biomass and activities suggested varying biomass-specific transformation intensities in the soils. The metabolic quotient (qCO2), defined as the respiration rate per unit of biomass, indicates the efficiency in acquiring organic C and the intensity of C mineralization, while biomass-specific arginine-ammonification (arginine-ammonification rate related to microbial biomass content) seems to be dependent on N availability. The qCO2, calculated on the basis of the total microbial biomass, decreased for the topsoils in the same order as did the ratio between the active, glucose-responsive microbial biomass to the total, chloroform-sensitive microbial biomass, in contrast to qCO2 values based on the glucose-responsive microbial biomass, which did not. There was no difference between the levels of biomass-specific arginine-ammonification in topsoils of the fertilized field-CR, fertilized field-MM, fertilized dry grassland and eutric alder forest, but levels were lower in the beech forest, dystric alder forest, and unfertilized wet grassland topsoils. Ratios between values of different microbiological features are suggested to be more useful than microbiological features related to soil weight when evaluating microbial populations and microbially mediated processes in soils.
AB - The content levels and activities of the microbiota were estimated in topsoils and in one soil profile at agricultural and forest sites of the Bornhoved Lake district in northern Germany. Discrepancies between data achieved by fumigation-extraction (FE) and substrate-induced respiration (SIR), both used for the quantification of microbial biomass, were attributed to the composition of the microbial populations in the soils. In the topsoils, the active, glucose-responsive (SIR) versus the total, Chloroform-sensitive microbial (FE) biomass decreased in the order; field maize monoculture (field-MM)>field crop rotation (field-CR) and dry grassland>beech forest. This ratio decreased within the soil profile of the beech forest from the litter horizon down to the topsoil. Differences between microbial biomass and activities suggested varying biomass-specific transformation intensities in the soils. The metabolic quotient (qCO2), defined as the respiration rate per unit of biomass, indicates the efficiency in acquiring organic C and the intensity of C mineralization, while biomass-specific arginine-ammonification (arginine-ammonification rate related to microbial biomass content) seems to be dependent on N availability. The qCO2, calculated on the basis of the total microbial biomass, decreased for the topsoils in the same order as did the ratio between the active, glucose-responsive microbial biomass to the total, chloroform-sensitive microbial biomass, in contrast to qCO2 values based on the glucose-responsive microbial biomass, which did not. There was no difference between the levels of biomass-specific arginine-ammonification in topsoils of the fertilized field-CR, fertilized field-MM, fertilized dry grassland and eutric alder forest, but levels were lower in the beech forest, dystric alder forest, and unfertilized wet grassland topsoils. Ratios between values of different microbiological features are suggested to be more useful than microbiological features related to soil weight when evaluating microbial populations and microbially mediated processes in soils.
KW - Arginine-ammonification rate
KW - Microbial biomass content Microbial activities Metabolic quotient Ecosystem research
UR - http://www.scopus.com/inward/record.url?scp=0031687744&partnerID=8YFLogxK
U2 - 10.1007/s003740050446
DO - 10.1007/s003740050446
M3 - Article
AN - SCOPUS:0031687744
SN - 0178-2762
VL - 27
SP - 374
EP - 379
JO - Biology and Fertility of Soils
JF - Biology and Fertility of Soils
IS - 4
ER -