Author/Authors :
Christensen، نويسنده , , S. and Rّnn، نويسنده , , R. and Ekelund، نويسنده , , Brian F. and Andersen، نويسنده , , B. M. Damgaard and C. Lauridsen، نويسنده , , J. and Friberg-Jensen، نويسنده , , U. Bindslev-Jensen، نويسنده , , L. and Kill، نويسنده , , H. and Larsen، نويسنده , , B. and Larsen، نويسنده , , J. and Riis، نويسنده , , C. and Thingsgaard، نويسنده , , K. and Thirup، نويسنده , , C. and Tom-Petersen، نويسنده , , A. and Vesterdal، نويسنده , , L.، نويسنده ,
Abstract :
Carbon, nitrogen or phosphorus limitation of microbial growth in a forest and a field soil was evaluated from measurements of respiration and protozoan counts after nutrient addition. In both soils simultaneous addition of C (glucose) and N (NH4NO3) resulted in microbial growth as indicated by a gradual increase in respiration rate whereas a single addition of C did not induce microbial growth. Addition of P (KH2PO4 + Na2HPO4) to C-amended soil stimulated activity slightly in forest soil but not in field soil whereas addition of P to soil amended with C and N increased growth markedly in both soils. The stimulation of microbial growth indicated by respiration profiles following C and N addition was supported by enumeration of bacterivorous protozoa. The numbers of soil protozoa increased above the control only when C and N were added simultaneously. These observations lend support to the proposal that respiration patterns may be valuable in an analysis of nutrient limitation of microbial growth in soils.
