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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A study of the errors involved in the sampling of soils

Steyn, Willem Johannes Abraham January 1945 (has links)
The importnnce of representative soil sampling is now beginning to receive more general recognition. The analysis of the sample, and any chemical or physical treatment it may undergo in the laboratory, is of little practical value if it is not known with reasonable certainty that this sample represents fairly the area from which it as taken. It has been said over and over again, that the existence of the world's whole civilization is dependent upon a mere strip of soil, only 9 inches in depth. The study of the soil is therefore of special importance if only for the practical end of replacing any nutrient deficiencies which may be found. Intro., p. 1.
22

Soil-water chemistry relationships and characterization of the physical environment : intermittent permafrost zone, Mackenzie Valley, N.W.T.

Walmsley, Mark E January 1973 (has links)
A discussion is presented to illustrate the relationships among landform, soil, vegetation and water chemistry in the intermittent permafrost zone of the Mackenzie Valley, Northwest Territories. Two study areas were examined in this region, one in the vicinity of Wrigley and the other in the vicinity of Fort Simpson, N.W.T. A catenary sequence of soils and vegetation occurring as a transect on five distinctive landforms were examined in the Wrigley area. The transect extended from 1170 m above sea level downslope to 500 m above sea level. The five landforms were: an alpine meadow, an area of stone stripe and stone ring formation, a colluvial slope, a coalescing fan and an area of polygonal bog formation. Information on chemical water quality is presented for each of these areas for the parameters pH, O₂, Ca, Mg, Na, K, Cl, F and NO₃. Chemical water quality presented for the Fort Simpson study area allows for the differentiation of different types of organic terrain based on the dissolved load of the saturated organic materials. The polygonal bog landform initially examined in the Wrigley area formed one of the differentiated types of organic terrain. The results are discussed with reference to organic terrain morphology and the distribution of permafrost in the study area. / Land and Food Systems, Faculty of / Graduate
23

The relationship of metals and soil organic components with particular reference to copper

Cross, Christine Hazel January 1975 (has links)
An ap horizon of a soil collected from a highly mineralized area was fractionated into five organic and mineral components and the distribution of cu, zn, pb, ca and mg within these components was determined. Zn and ca were removed to a considerable degree in the 0.1n hcl extract. Of the five metals, cu and pb were the only ones present which combined with organic matter to any considerable degree. Of the five organic and mineral components, fulvic acid was shown to display the greatest complexing activity. Although gel filtration has been used extensively in the field of biochemistry, it was shown that the metal retaining properties of the various sephadex and agar gels used caused the technique to be unsuitable for the separation of naturally occurring metal-organic complexes. In addition the distribution of fe, cu and zn within the profiles of two soils from less mineralized areas was determined but the low levels of metal found did not permit a direct investigation of their metal-organic complexes. In order to study in detail metal-0rganic matter reactions, humic acids were extracted from several of the above soils. Functional group analysis coupled with elemental analysis for c, h, N and 0 in these humic acids revealed that a large percentage of the oxygen was unaccounted for in carboxylic acid and phenolic Hydoxylic groups, thus indicating the presence of other oxygen containing groups. Infrared spectra showed decreases in the amount of aliphatic material present with increasing maturity of the humic acids and also gave supporting evidence of complex formation upon the addition of cu. The humic acids were used in a series of incremental potentio- Metric titration experiments which monitored the pattern of proton release in response to copper additions at a series of ph levels. The resultant curves for humic acids of various origins were alike in their general shapes but displayed differences in detail which were especially marked between the juvenile and the more mature acids. Whereas in all cases of humic acids derived from mineral soils the proton release increased with ph, the peat humic acid displayed a greater proton release at ph 5.0 than at ph 6.0. The shapes of the curves obtained with humic acids were compared with those obtained in similar experiments from a series of model compounds of known chemical composition and were found to approximate most closely the patterns derived from salicylic acid and phthalic acid. This provides additional evidence for the hypothesis that salicylic and phthalic acid-like functional groups play a significant role in the formation of metal-organic complexes in soils. / Land and Food Systems, Faculty of / Graduate
24

Soluble constituents and ion exchange reactions of Champlain sea sediments.

Laventure, Reginald S. January 1964 (has links)
No description available.
25

Exchange of sodium on clay minerals by leaching with calcium sulphate.

Chaudhry, Ghulam Haider. January 1965 (has links)
No description available.
26

A comparative study of virgin and cultivated orthic podzol soils.

Bailey, R. Edward. January 1969 (has links)
No description available.
27

PROPANE REMOVAL BY SOILS: LABORATORY AND FIELD EXPERIMENTS

Ebinger, Michael Howard January 1984 (has links)
No description available.
28

The Physico-Chemical Relationships of Soil Phosphates

Buehrer, T. F. 30 June 1932 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
29

The So-Called "Build-Up" and "Break Down" of Soil Zeolites as influenced by Reaction

Burgess, P. S. 15 September 1929 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
30

Electrodialysis as a Measure of Phosphate Availability in Soils and the Relation of Soil Reaction and Ionization of Phosphates to Phosphate Assimilation

McGeorge, W. T. 01 March 1932 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

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