Bacterial, fungal and protozoan responses to chloroform fumigation in stored soil

https://doi.org/10.1016/0038-0717(87)90097-6Get rights and content

Abstract

Microbial biomass estimated by CO2 evolution following fumigation was 2.5–14.7 times greater than that estimated by direct microscopy in prairie soil. Bacteria, fungi and protozoa were counted by direct microscopy before, during and periodically for 10 days following chloroform fumigation and compared with microbial biomass as estimated by CO2 evolution and N mineralization following chloroform fumigation. Protozoan populations were reduced to below detection levels immediately after fumigation and remained below detection levels during incubation following fumigation. Bacterial and fungal populations were reduced by fumigation to 37–79% of their original populations but usually recovered to their initial numbers by the second day following fumigation. In one case protozoa contributed up to 74 μg C, or about half of the total microbial biomass, to CO2 evolution following fumigation.

Microbial biomass was estimated in soil wetted to 60% of water-holding capacity (WHC) 1 wk or 1 day before fumigation. Microbial activity changed during the 1 wk incubation before fumigation but not total microbial biomass determined by microscopy.

The ratio of CO2 evolved-to-N mineralized followed fumigation changed in direct proportion to the ratio of fungal-to-bacterial biomass present in the soil before fumigation. Although more experiments with different soils should be performed, these results indicate that CO2 evolved or N mineralized varies with the ratio of fungal-to-bacterial biomass initially present.

References (24)

Cited by (72)

  • Correlation of WorldView-3 spectral vegetation indices and soil health indicators of individual urban trees with exceptions to topsoil disturbance

    2021, City and Environment Interactions
    Citation Excerpt :

    The soil was sieved (2 mm), and active bacterial and fungal-hyphae biomasses were measured using fluorescein diacetate staining. The length of active and total fungal hyphae was determined following the procedures of Ingham and Klein [42], Ingham and Horton [43], and Lodge and Ingham [56]. The biovolume-to-biomass conversion rates of Van Veen and Paul [85] were applied as necessary.

  • Separating cellular metabolism from exoenzyme activity in soil organic matter decomposition

    2014, Soil Biology and Biochemistry
    Citation Excerpt :

    The fumigation itself typically lasts 1–3 days (Jenkinson and Powlson, 1976; Foster, 1988; Dickens and Anderson, 1999). If given enough time, CHCl3 diffuses into soil micropores and kills most—but not all—soil bacteria and fungi (Ingham and Horton, 1987; Alphei and Scheu, 1993; Toyota et al., 1996). Soils may also be incubated under CHCl3 to prevent microbial regrowth.

View all citing articles on Scopus

Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A.

Department of Plant and Soil Biology, University of California, Berkeley, CA 94720, U.S.A.

View full text