A MICROBIOLOGICAL STUDY OF PODSOL SOIL PROFILES

1933 ◽  
Vol 8 (4) ◽  
pp. 375-389 ◽  
Author(s):  
P. H. H. Gray ◽  
N. B. McMaster
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Nitrate Nitrogen ◽  
Soil Profiles ◽  
Toxic Compounds ◽  
Microbiological Study ◽  
Different Depths ◽  
Micro Organisms ◽  
Reduced Activity ◽  
Production Of Ammonia

Microbiological studies of samples from the separate horizons and from different depths of soils of the Appalachian upland podsol group show that the activity of the micro-organisms is dependent upon the organic-matter relations in the horizons. The organic-matter horizon is biologically the most active, as shown by analyses for carbon dioxide, nitrate nitrogen, numbers of bacteria, and production of ammonia from urea. Evidence is submitted that the reduced activity of the leached layer and the horizons of accumulation is not due to toxic compounds produced by leaching of the organic matter.

A MICROBIOLOGICAL STUDY OF PODSOL SOIL PROFILES: II. LAURENTIAN SOILS

1935 ◽  
Vol 13c (4) ◽  
pp. 251-255 ◽  
Author(s):  
P. H. H. Gray ◽  
C. B. Taylor
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Biological Activity ◽  
Clay Soil ◽  
Sharp Contrast ◽  
Soil Profiles ◽  
Microbiological Study ◽  
Micro Organisms ◽  
Different Levels ◽  
Production Of Ammonia

Microbiological studies of samples from the separate horizons of two soils from the Laurentian uplands showed that, as in the case of the soils previously studied from the Appalachian uplands, biological activity was dependent upon the organic-matter relations of the horizons. A1 (organic-matter) horizons were the most active, as shown by the evolution of carbon dioxide, nitrification of the soil's own nitrogen, by numbers of micro-organisms (bacteria, actinomyces, and fungi) and by the production of ammonia from urea. Bacterial numbers in the illuvial horizons were, however, higher than in the eluvial (leached) horizons above, a condition that did not obtain with the Appalachian soils. The organic matter of a soil bearing a coniferous (spruce) flora was deficient in nitrifying power. The biological activity at different levels of a virgin clay soil was found to be in sharp contrast with that of the podsol soils.

scholarly journals Biochemistry of waterlogged soils. Part III: Decomposition of carbohydrates with special reference to formation of organic acids

1929 ◽  
Vol 19 (4) ◽  
pp. 627-648 ◽  
Author(s):  
V. Subrahmanyan
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Organic Acids ◽  
Pyruvic Acid ◽  
Soluble Nitrogen ◽  
Direct Oxidation ◽  
Micro Organisms ◽  
Organic Matter Addition

(1) In absence of decomposing organic matter addition of nitrate led to no loss of nitrogen.(2) On addition of small quantities of fermentable matter such as glucose there was (a) rapid depletion of nitrates and oxygen, but no denitrification, and (b) increase in acidity, carbon dioxide and bacteria. The greater part of the soluble nitrogen was assimilated by microorganisms or otherwise converted and the greater part of the added carbohydrate was transformed into lactic, acetic and butyric acids.(3) The organic acids were formed from a variety of carbohydrates. Lactic acid was the first to be observed and appeared to be formed mainly by direct splitting of the sugar. It decomposed readily, forming acetic and butyric acids. Some acetic acid was formed by direct oxidation of lactic acid, with pyruvic acid as the intermediate product. All the acids were, on standing, converted into other forms by micro-organisms.

A comparison of the mineralization of nitrogen and of sulphur from decomposing organic materials

1960 ◽  
Vol 11 (6) ◽  
pp. 960 ◽  
Author(s):  
NJ Barrow
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Nitrate Nitrogen ◽  
Inorganic Nitrogen ◽  
Plant Materials ◽  
Wide Range ◽  
Sulphate Sulphur ◽  
Microbial Residues ◽  
Residual Organic Matter ◽  
Native Organic Matter

The decomposition of a wide range of plant materials added to soil waa studied by measuring the production of carbon dioxide, and changes in the concentrations of ammonium and nitrate nitrogen and sulphate sulphur. The amount of sulphur mineralized depended on the sulphur content and the carbon/sulphur (C/S) ratio of the organic matter in much the same way as the amount of inorganic nitrogen depended on the nitrogen content and the carbon/nitrogen (C/N) ratio. For any given C/S or C/N ratio the sulphur or nitrogen mineralized varied within quite wide limits. With a 12 week decomposition period, initial C/S ratios of 200 and 420 were the minimum and maximum values at which no mineralization of sulphur occurred. The corresponding values for nitrogen were 16 and 44. Calculations indicated that the microbial residues from easily decomposed materials had a C/N ratio of 6–7 and a C/S ratio of 50–60, but with the residual organic matter from the more resistant materials the ratios were wider. Where large quantities of nitrogen were mineralized the decomposition of the native organic matter was stimulated.

scholarly journals The effect of oxygen on fermentation of sucrose by rumen micro-organisms in vitro

1969 ◽  
Vol 23 (1) ◽  
pp. 67-80 ◽  
Author(s):  
J. W. Czerkawski ◽  
Grace Breckenridge
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Gas Phase ◽  
Particulate Organic Matter ◽  
Measurable Effect ◽  
A Value ◽  
Net Uptake ◽  
Effect Of Oxygen ◽  
Micro Organisms

1. The effect of oxygen on the fermentation of sucrose by mixed rumen micro-organisms in vitro was studied by adding oxygen to the gas phase in three ways: at the beginning of incubation, at two hourly intervals during incubation and continuously.2. The additions of oxygen had no measurable effect on the utilization of sucrose or on the production of carbon dioxide, steam-volatile acids and particulate organic matter by the micro-organisms. The addition of oxygen at the beginning of incubation inhibited methane production and increased the accumulation of hydrogen. Similar but much less pronounced changes occurred when the oxygen was infused continuously.3. In all the experiments there was a net uptake of oxygen by micro-organisms. When large amounts of oxygen were present in the gas phase the rates of uptake were proportional to these amounts. When small amounts of oxygen were added, the rates of uptake were independent of the amount added and had a value of approximately 5 ml/h when 100 ml of strained rumen contents were incubated.

Forms of Lead in Profiles of Differently Use Soil

2012 ◽  
Vol 63 (4) ◽  
pp. 41-45 ◽  
Author(s):  
Iwona Makuch
Keyword(s):  
Organic Matter ◽  
Lead Content ◽  
Soil Profiles ◽  
Allotment Gardens ◽  
Arable Field ◽  
Fraction I ◽  
The Town ◽  
House Gardens ◽  
Humus Horizons

Abstract In order to determine the influence of intensive horticulture on the amount of lead and its fraction contents, there were selected soil profiles from following objects to be researched: house gardens and allotment gardens from town areas and arable field on the outskirts of the town. It has not been determined that there is any influence of manner usage on total lead content as well as its distribution in soil profiles. The fractionation composition has created the following series: fraction IV > fraction III > fraction II > fraction I. The manner of usage has influenced the content and distribution the III fraction of lead connected with organic matter. Humus horizons of garden soils is characterized as the highest in its content.

A pedological study of phosphorus in 12 soils derived from granite

1961 ◽  
Vol 12 (2) ◽  
pp. 286 ◽  
Author(s):  
A Wild
Keyword(s):  
Organic Matter ◽  
Chemical Analysis ◽  
Soil Profiles ◽  
Rock Weathering ◽  
Simple Correlation ◽  
Methods Of Calculation ◽  
Parent Rocks

Chemical analysis of 12 soil profiles on granite showed that all except two had lost phosphate by leaching. The loss of phosphorus from each profile is calculated in grams per sq centimetre of profile surface, and as a percentage of the amount originally present. Three methods of calculation are used, each being based on one of the following assumptions as to the changes which take place on rock weathering: that there is (a) no change in weight, (b) no change in volume, (c) no loss of zirconium. The three methods are generally consistent in showing which soils are the most leached and which are the least leached. The estimated loss of phosphorus from each profile depends on which assumption is made. There is no simple correlation between the loss of phosphorus and the present rainfall. Reasons which are suggested are that the soils differ in age, in level of organic matter, and possibly in the rates of weathering of the parent rocks. Up to two-thirds of the phosphorus retained in the soil is chemically bound by the free oxides of iron and aluminium.

scholarly journals Some chemical and bacterial characteristics of bottom deposits from lakes and estuaries

1953 ◽  
Vol 51 (2) ◽  
pp. 185-194 ◽  
Author(s):  
L. A. Allen ◽  
J. Grindley ◽  
Eileen Brooks
Keyword(s):  
Bacteriological Examination ◽  
Surface Layers ◽  
Digested Sludge ◽  
Faecal Pollution ◽  
Bottom Deposits ◽  
Low Concentrations ◽  
Different Types ◽  
Different Depths ◽  
Micro Organisms ◽  
Reducing Bacteria

Chemical and bacteriological examination of muds from sources differing widely in the degree of pollution to which they were subject showed great differences in the contents of carbon, nitrogen and sulphide. These differences were not correlated with differences in the severity of faecal pollution. The amount of organic matter available for growth of micro-organisms in the mud of different depths was not reflected in the figures for organic carbon. A convenient index of this factor was obtained by measuring the volume of gas evolved during anaerobic digestion over a prolonged period of incubation. The rate of evolution was increased by the addition of an inoculum of digested sludge from a sewage works.Sulphate-reducing bacteria appeared to be of two different types. In samples of mud from fresh-water lakes much higher counts were usually obtained in a medium containing comparatively low concentrations of inorganic salts and of lactate than in a medium containing much higher concentrations of these constituents. In samples from locations where conditions were more saline the reverse was usually true.Counts of Bact. coli and of Strep, faecalis together probably constitute the best index of faecal pollution in the examination of samples of mud. These organisms are, however, largely confined to the surface layers.

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