Investigations in the field of soil fertility have for a long time suggested a relationship between uptake of the so-called trace elements by plants and the presence of organic matter. The manner in which this influence is exerted is still not fully understood because of the complexity of the nature and properties of soil organic matter and its relationships with the inorganic material in soil. Progress in the study of the properties of soil organic matter is, in turn, hindered by the absence of a satisfactory method of extracting this material and purifying it to remove all the inorganic cautions especially the heavy metal ions. Existing methods of extraction are either inefficient in terms of the amount organic matter which they dissolve or open to criticism on chemical grounds. There have been few serious attempts either to investigate the possibility of employing new methods or to improve existing methods of purification. This thesis is divided into two parts: Part A consisting of four chapters, presents a brief review of the relevant literature in which an attempt has been made to report and assess the present state of our knowledge. In chapter I the evidence for complex formation between soil organic matter and metal cations is reviewed and the physico chemical methods employed in studying these complexes are surveyed. Chapter II covers the methods of extraction and the conclusion is drawn that anhydrous formic acid has many favorable advantages over the widely used conventional aqueous extractants. The Procedures for removing inorganic impurities from soil organic matter are reported in chapter III and the review shows that purification has received comparatively little attention. From the information presented in Chapter IV on the iron and copper nutrition of plants is appears that several factors influence their availability. It is well known that synthetic chelating agents increase the availability of these cations but there is very little information to hand to explain the influence of soil organic matter on their uptake. Part II records the methods used and the results obtained in the experimental studies. Chapter V Explains the experimental aims and describes the analytical procedures employed. The remaining chapters correspond to those of the review but deal with the topics in a different order. Because of the complexing ability of organic matter a chelating agent, namely acetyl aceton was included in formic acid in a attempt to achieve a better separation of the organic and inorganic compounds. A variety of purification methods were examined and finally a procedure was obtained which reduced the ash content to below 1 this allowed a study of the physico-chemical aspects of the complexing properties of relatively pure material and the influence of this material on the uptake of metals by mustard seedling grown under sterile conditions on a simple nutrient medis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:593387 |
| Date | January 1965 |
| Creators | Salardini, Ali Akbar |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU283515 |
Page generated in 0.0014 seconds