UK

1962 - 1969

Research Assistant

Department of Soil Science, University of Aberdeen, Scotland

 

 

After graduation from the Soil Science Department having studied under Joe Tinsley, John Parsons, Dr Couts and Fitz (Ewart Fitzpatrick) became Research Assistant in the Soil Science Department gaining an M.Sc. whilst also carrying out routine analyses of soil samples and specialised analyses on soil organic matter, including gas chromatography techniques. Also involved in organising and running laboratory classes for undergraduate and post-graduate students.

Worked with Professor Joe Tinsley and the late John Parsons - who succeeded Joe Tinsley to the Chair of Soil Science. A great deal of the work was involved with the extraction of Soil Organic Matter with formic acid and the subsequent analysis of the extract for nitrogen and organic content. Developed methods for detailed analyses for sugars using thin film chromatography and, laterally, gas chromatography.

MSc Thesis (1967) " Chemical Changes in Forest Litter following the Application of Nitrogen Fertilisers". Sample plots had previously been laid out at Alice Holt research station (Farnham Surrey) and samples of the surface litter were collected at regular intervals. Studies on the actual tree growth were undertaken by Forestry Commission Staff from Alice Holt.

Eventually took two years sabbatical to undertake overseas contact with ODA as soil surveyor in Nigeria - partly as recuperation following explosion in the laboratory whilst recovering silver from coated flask used for extractions with nitric acid. Later determined that the accident was caused as two fumes cupboards were interlinked from different rooms - the other room was being used for distillation of ether!!

MSc Thesis: Introduction

When trees reach the pole stage of their development growth often proceeds slowly and attempts have been made to alter this situation and thereby produce timber more quickly and hence economically.

The Forestry Commission began experiments on pole stage Scots pine in 1958 by applying nitrogen, phosphorus, potassium, calcium and magnesium and although there were no significant effects on the growth of the trees there were marked differences in the forest litter. The physical nature of the litter had been altered by an increased rate of humification following application of nitrogen fertilisers, particularly when in combination with lime.

The intention of the present study is to assess the changes in composition and properties of Scots pine litter, in the field, following the application of nitrogenous fertilisers with and without lime.

In Part I of this thesis there is a review of the literature which is divided into three chapters. Chapter One deals with the nutrient cycle in the soil forest system, Chapter Two reviews the use of fertilisers for improving tree growth - from the nursery right through to pre-felling fertilisation - and Chapter Three deals with the chemical changes in forest litter, with particular reference to nitrogen transformation.

In the experimental part the aims and design of both field and laboratory experiments are given along with the methods and techniques used and developed. The results obtained personally and by the Forestry Commission are fully discussed and conclusions drawn.

MSc Thesis: Summary

  1. The literature on the nutrient cycle in the forest / soil system, the use of fertilisers for improving tree growth and chemical changes in forest litter was reviewed.

  2.  A study was made of the composition of drainage water from micro-lysimeters installed in the experimental plots; total and ammonia nitrogen were determined along with organic carbon and the effects of urea were shown to be different in the first year following application.

  3. Dr. W.O. Binns of the Forestry Commission arranged for tree girth measurements and needle analysis to be carried out in order to see what effects the treatment had on growth. Liming and addition of urea caused some slight improvement after four years though the changes were barely significant.

  4. In the experimental section the study of the litter was divided into three sections: -

  1. Changes in gross composition of samples from field plots. The changes that occurred were due more to liming than to nitrogen fertiliser treatments. These were: reduced organic matter content, increased reducing sugar content and pH and the appearance of fungal fruiting bodies.

  2. Composition of material soluble in hot formic acid / acetyl acetone. Application of lime increased the percentage of organic matter soluble in the extractant, the ash and amino acid contents of the extracted material, had no clear cut effect on the amino sugar content and reduced both the percentage of litter nitrogen soluble in the extractant and the nitrogen content of the extracted material. Application of nitrogen fertiliser reduced the amount of litter nitrogen soluble in extractant. Urea produced more amino acid and amino sugar than the other fertilisers. Normally the N1 rate of application gave higher contents of amino acids and sugars than the N3 rate except for urea in which case the rate had no definite effect.

  3. The distribution of reducing sugars in the formic acid soluble material was studied after development of a suitable gas / liquid chromatographic method. The sugars found were xylose, galactose, glucose and mannose - there was a general trend for the overall means to be higher in Autumn than in Spring.