Browse on keywords: soil quality microbial activity
Search results on 05/20/13
7103. Vandecaveye, S.C. and C.D. Moodie. 1942. Occurrence and activity of Azotobacter in semiarid soils in Washington.. Soil Sci. Soc. Am. Proc., 7:229-236.
The Azotobacter population in any of the nonirrigated semiarid soils tested was too small to contribute significantly to nitrogen fixation.
178. Alef, K. and D. Kleiner. 1989. Rapid and sensitive determination of microbial activity in soils and in soil aggregates by dimethylsulfoxide reduction.. Biol. Fert. Soils 8:349-355.
Based on the reduction of dimethylsulfoxide (DMSO) to dimethylsulfide (DMS) by microorganisms, a simple, rapid, sensitive and inexpensive method for the determination of microbial activity in soil samples was developed. When DMSO was added to samples, DMS appeared immediately in the gas phase, which was quantitatively analyzed by gas chromatography. The DMS liberation rate was constant for several hours. The reaction immediately starts and its linearity indicate that neither the physiological state nor the number of organisms were changed by the assay. The method is sufficiently sensitive to allow measurements of activity in very small samples.
2578. Peeters, J.F., A.R. Van Rossen, K.A. Heremans and L. Delcambe. 1975. Influence of pesticides on the presence and activity of nitrogenase in Azotobacter vinelandii.. J. Agric. Food Chem., 23(3):404-406.
The influence of various pesticides on the growth of Azotobacter vinelandii was tested under nitrogen fixing conditions. Growth was stimulated in nearly all cases. The presence of nitrogenase in bacterial extracts was greatly reduced. Inhibition experiments showed that organochlorine compounds have no influence on the reduction of acetylene. Derivatives of 2,4-dinitrophenol inhibit in a specific way. A wide range of pesticides were tested.
7095. Vandecaveye, S.C. and B.R. Villanueva. 1934. Morphological relationships of soil microbes.. J. Bacteriology 27:257-269.
Looked at microbial groups active in a soil with annual application of 12 T/ac manure for 27 yr, with annual winter wheat vs. soil with no fertilizer and wheat-fallow for 27 yr. Manured soil had a marked increase in numbers of both authochthonous and zymogenic organisms. Soil amendments in the lab elicited different CO2 responses that were not consistent with the bacterial numbers.