Fungal and bacterial growth in soil with plantmaterials of different C/N ratios

Research output: Contribution to journalArticle


Fungal (acetate-in-ergosterol incorporation) and bacterial (leucine/thymidine
incorporation) growth resulting from alfalfa (C/N = 15) and barley straw
(C/N = 75) addition was studied in soil microcosms for 64 days. Nitrogen
amendments were used to compensate for the C/N difference between the
substrates. Fungal growth increased to a maximum after 3–7 days, at five to eight
times the controls, following the addition of straw, and three to four times the
controls following the addition of alfalfa. After 20–30 days, the fungal growth rate
converged with the controls, resulting in a cumulative fungal growth two to three
times the controls following straw addition and about 20% higher than
the controls following alfalfa addition. The bacterial growth rate reached rates five
times the controls following alfalfa addition and twice that of the controls
following straw addition after 3–7 days. It remained elevated after 64 days. The
cumulative bacterial growth was two and four times the controls following straw
and alfalfa addition, respectively. A negative correlation was found between
N addition and bacterial growth, while N stimulated fungal growth. Thus, the
C/N ratio of the additions (substrate and extra N) could not entirely explain the
different results regarding fungal and bacterial growths. Respiration was not always
related to the combined growth of the microorganisms, emphasizing the requirement
for a better understanding of growth efficiencies of fungi and bacteria.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biological Sciences


  • leucine/ thymidine incorporation, acetate-in-ergosterol incorporation, fungal and bacterial growth in soil, C/N ratio, ergosterol, phospholipid fatty acid.
Original languageEnglish
Pages (from-to)258-267
JournalFEMS microbiology ecology
Issue number3
Publication statusPublished - 2007
Publication categoryResearch