Published on November 5, 2008
b.stev Microbial Biomass in Soil
What is MICROBIAL BIOMASS ?
SOIL BIOTA IS INFLUENCED BY: HOW the land is used Management techniques CHANGE of the practises this has effect to the microbial process & their functions of survival in the soil
RESIDUE left after CROPS are harvested is nutrient to soil & facilitates the next crop growth .
MICROBES transform chemicals aid pesticide degradation participate in soil formation contribute to soil aggregation
aid pesticide degradation
participate in soil formation
contribute to soil aggregation
The limits of measurement: analytical cost involved ambiguous relationship to product benchmark values/ interpretation requires time to establish results cumbersome/ time needs
The limits of measurement:
analytical cost involved
ambiguous relationship to product
benchmark values/ interpretation
requires time to establish results
cumbersome/ time needs
DEMAND HAS INCREASED: can monitor soil quality an environmental monitor rapid/ improved techniques gives the rates of turnover ANALYSIS for clean food
can monitor soil quality
an environmental monitor
rapid/ improved techniques
gives the rates of turnover
ANALYSIS for clean food
HOW is this DONE? Extraction of soil is done with a hollow rod to a depth of 10-15 cm Samples are filtered to remove: stones/ roots/ finer fibres: size 2mm Storage is at 4 o C SAMPLES are taken in squares at appropriate spacings to ensure all land variations are included; it is quite an extensive process
20g soil are fumigated for a period of 24hrs with CHLOROFORM (CHCl 3 ) in a humid dessicator THEN: sample is inoculated with 0.5g fresh soil & placed in 1L airtight jars incubated 10 days at room temperature Controls - 20.5g samples are put in glass jars at time of fumigation are put to incubation : 10 days method : chloroform fumigation, incubation analyses the concentrations: carbon & nitrogen
CO 2 produced in the headspace above the incubated samples is determined by: GAS CHROMATOGRAPHY Bc = ( Fc / Kc) CALCULATION performed from the results: Kc = 0.41 factor Bc = biomass of controls Fc = fumigated samples DATA is kept in graph/ & numerical value Field/ SAMPLE sites, mapped for reference
Manufacturer, “ Heinemeyer ”- produced an instrument that determines microbial biomass by INFRARED ANALYSER Soil pH - potentiometric 0.01M CaCl 2 suspension H 2 O content: samples - oven dried 105 o C 24hr CNS-2000 analysis uses dry combustion to measure both the carbon & nitrogen content SOME OTHER METHODS & analysis to perform ARE:
Bibliography Archbold Biological Station. (2008). Soil microbial biomass . Retrieved September 26, 2008, from http://www.archbold-station.org/abs /publicationPDF/Groffman,etal.-2004-Ecosystems.pdf. Soil Quality Pty Ltd. (2007). Soil quality . Retrieved September 25, 2008, from http://www.soilquality.org.au/factsheets/microbial-biomass Rothamsted Research. (2004). Method download - soil microbial biomass group - rothamsted . Retrieved September 26, 2008, from http://www.rothamsted. ac.uk/aen/smbweb1/methods.php?id=903
Microbial Biomass Key points. Microbial biomass (bacteria and fungi) is a measure of the mass of the living component of soil organic matter. The microbial ...
4. Determining soil microbial community differences using eco-physiological parameters. The basis of two of our papers (Anderson and Domsch, 1989 and ...
The microbial biomass of soil is defined as the part of the organic matter in the soil that constitutes living microorganisms smaller than the 5-10 um 3.
Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains
Microbial Biomass – Queensland Key Points. Soil microbial biomass (bacteria, fungi and protozoa) is a measure of the mass of the living component of soil ...
The ratio of microbial biomass carbon (Cmic) to total organic carbon (Corg) was measured in soils from long-term agricultural experiments located in the ...
Methods for measuring soil microbial biomass C were reviewed. The basic ideas behind the fumigation-incubation method, the fumigation-extraction method ...
Ergosterol and microbial biomass relationship in soil,10.1007/s003740050115,Biology and Fertility of Soils,G. Djajakirana,R. G. Joergensen,B. Meyer.
A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems