Microbial biomass of a grassland soil as estimated by the fumigation and direct counting methods

Tesařová, Marta; Řepová, A.

doi:10.1007/bf02872936

Cited by 13 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mycelia dominated bacteria in terms of volume and mass, whereas bacteria dominated mycelia in terms of surface area in these soils, with the ratios generally falling in the range determined for other soils (e.g., Shields et al 1974;Nikitina et al 1982;Nannipieri et al 1983;Tesarova & Repova 1984). However caution must be exercised in interpreting these data; the measurements of mycelial lengths and bacterial numbers were not corrected for efficiency of extraction from soil (Nishio 1983;Ramsay 1984), discrimination of bacteria into separate morphological groups is subjective (Jenkinson et al 1976;Hasebe et al 1984), and selection of nominal volume categories affects total volume estimates (Lundgren 1984).…”

Section: Mycelial:bacterial Ratiosmentioning

confidence: 65%

“…Estimates of the size of these microbial populations by direct (microscopic) observation of a wide variety of soils, under arable and grassland regimes, has revealed that the ratios of mycelial (fungal and actinomycete organisms): bacterial (discrete spherical and rod-shaped organisms < 1.5 p.m 3 ) volume and mass both differ substantially from unity. Arable soils have mycelial:bacterial volume or mass ratios ranging between 3.7 and 6.5 (Shields et al 1974;Jenkinson et al 1976 -here we use ratios based on their data for sphericiJ.I organisms of only 2.2 p.m 3 or less and cylindrical organisms of all diameters ;Nishio 1983), whereas grassland soils appear to have slightly lower ratios, ranging from 1.1 to 5.5 (Jenkinson et al 1976;Nannipieri et al 1983;Tesarova & Repova 1984). Thus in terms of volume and mass, mycelial organisms typically dominate bacteria in these soils.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ratio of mycelial to bacterial volumes in arable and grassland soils of differing water contents

West¹,

Slade

1987

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

One arable and two grassland soils were sieved < 2 mm, air-dried and subsamples rewetted to a range of water contents. They were then incubated for 7 days at 25°C before mycelial (M, fungal and actinomycete organisms) and bacterial (B, discrete organisms < 1.5 p.m 3 ) volumes were estimated by light microscopy. Mycelial and bacterial volumes, surface areas, and masses, and their respective ratios all differed significantly between soils, but not between water contents within soils. Bacterial volume (mean 0.10, modal 0.07 p.m 3 per bacterium) and morphology (890/0 of bacteria were coccal) were very similar for all three soils. However, mycelial populations differed between soils. Modal mycelial diameter was 1.5 p.m for all soils, but mean diameter was 2.8 p.m for one soil and 3.8 p.m for the other two soils. Total surface area was dominated by bacteria, whereas volume and mass were dominated by mycelia. In the two soils with similar microbial populations, total (i.e., visible) microbial volume (T, i.e., M + B) and mycelial:bacterial volume ratios (R, i.e., MIB) were related: are corrected for the apparently dead mycelia then R (= 0.67), the ratio of viable mycelial:bacterial volume, is independent of T, the total microbial volume. Inability to discriminate non-viable volume may have obscured significant correlations between water content and the microbial populations of these soils.

show abstract

Section: Mycelial:bacterial Ratiosmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Ratio of mycelial to bacterial volumes in arable and grassland soils of differing water contents

West¹,

Slade

1987

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

show abstract

“…Generally, the abundance of bacteria in the rhizosphere is reported to be greater than that in root‐free soil (Rovira et al , 1974; Tesařová & Řepová, 1984; Chin‐A‐Woeng et al , 1997; Gamalero et al , 2004; Watt et al , 2006), and rhizosphere bacterial density follows the trend: basal region>bulk soil>apical region (Fig. 3; Parke et al , 1986; Olsson et al , 1987; Liljeroth et al , 1991; Chin‐A‐Woeng et al , 1997; Duineveld & van Veen, 1999; Dennis et al , 2008).…”

Section: Rhizosphere Bacterial Communitiesmentioning

confidence: 98%

Are root exudates more important than other sources of rhizodeposits in structuring rhizosphere bacterial communities?

Dennis

Miller

Hirsch

2010

FEMS Microbiology Ecology

836

485

View full text Add to dashboard Cite

This review evaluates the importance of root exudates in determining rhizosphere bacterial community structure. We present evidence that indicates that: (1) the direct influence of root exudates on rhizosphere bacterial communities is limited to small spatiotemporal windows related to root apices; (2) upon rapid assimilation by microorganisms, root exudates are modified, independent of plant influences, before rerelease into the rhizosphere by the microorganisms themselves--thus, at short distances from root apices, rhizosphere carbon pools are unlikely to be dominated by root exudates; and (3) many of the major compounds found in root exudates are ubiquitous in the rhizosphere as they are found in other pools of rhizodeposits and in microbial exudates. Following this argument, we suggest that the importance of root exudates in structuring rhizosphere bacterial communities needs to be considered in the context of the wider contribution of other rhizosphere carbon pools. Finally, we discuss the implications of rhizosphere bacterial distribution trends for the development of effective strategies to manage beneficial plant-microorganism interactions.

show abstract

“…As well as containing more copiotrophs, rhizosphere bacterial populations are more numerous than those of bulk soil (Chin-A- Woeng et al, 1997;Gamalero et al, 2004;Rovira et al, 1974;Tesarova and Repova, 1984;Watt et al, 2006), with bacterial density following the trend: basal region > bulk soil > apical region as shown in Figure 22.3 and reported in the literature (Chin-A- Woeng et al, 1997;Dennis et al, 2008;Duineveld and Van Veen, 1999;Jones and Darrah, 1992;Liljeroth et al, 1991;Olsson et al, 1987;Parke et al, 1986). This counters the view that exudates determine the overall structure of rhizosphere bacterial communities, since they are released at root apices and rapidly mineralized.…”

Section: Bacterial Community Structure In the Rhizospherementioning

confidence: 74%

Do Root Exudates Exert More Influence on Rhizosphere Bacterial Community Structure Than Other Rhizodeposits?

Hirsch

Miller

Dennis

2013

Molecular Microbial Ecology of the Rhizosphere

View full text Add to dashboard Cite

show abstract

Microbial biomass of a grassland soil as estimated by the fumigation and direct counting methods

Cited by 13 publications

References 4 publications

Ratio of mycelial to bacterial volumes in arable and grassland soils of differing water contents

Ratio of mycelial to bacterial volumes in arable and grassland soils of differing water contents

Are root exudates more important than other sources of rhizodeposits in structuring rhizosphere bacterial communities?

Do Root Exudates Exert More Influence on Rhizosphere Bacterial Community Structure Than Other Rhizodeposits?

Contact Info

Product

Resources

About