Biology and Fertility of Soils

, Volume 22, Issue 3, pp 261–264 | Cite as

Changes in soil fungal:bacterial biomass ratios following reductions in the intensity of management of an upland grassland

  • Richard D. Bardgett
  • Philip J. Hobbs
  • Åsa Frostegård
Original Paper


In this study we examined the effect on soil fungal:bacterial biomass ratios of withholding fertiliser, lime, and sheep-grazing from reseeded upland grassland. The cessation of fertiliser applications on limed and grazed grassland resulted in a reduction in soil pH from 5.4 to 5.1. The cessation of fertiliser applications and liming on grazed grassland resulted in a fall in pH from 5.4 to 4.7, whereas withholding fertiliser and lime and the removal of grazing resulted in a further reduction to pH 4.5. Substrate-induced respiration was reduced in the unfertilised grazed (21%; P<0.01) and unfertilised ungrazed (36%; P<0.001) treatments. Bacterial substrate-induced respiration and bacterial fatty acids were unaffected by the treatments. The relative abundance of the fungal fatty acid 18:2ω6 increased by 39 and 72% (P<0.05) in the limed grazed and unfertilised grazed treatments, respectively. Fungal substrate-induced respiration increased in the limed grazed (18%) and unfertilised grazed (65%; P<0.05) treatments. The ratio of 18:2ω6: bacterial fatty acids was correlated with the ratio of fungal:bacterial substrate-induced respiration (r=0.69; P<0.001).

Key words

Phospholipid fatty acids Substrate-induced respiration Fungi Bacteria Sheep-grazing Fertiliser Lime Microbial biomass Soil 


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Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • Richard D. Bardgett
    • 1
  • Philip J. Hobbs
    • 2
  • Åsa Frostegård
    • 3
  1. 1.University of ManchesterManchesterUK
  2. 2.North Wyke Research, StationInstitute of Grassland and Environmental ResearchOkehamptonUK
  3. 3.Department of Microbial Ecology, Ecology BuildingUniversity of LundLundSweden

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