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Title: Comparative studies of biological nitrogen fixation under lowland and upland conditions
Author: Panas, B.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1981
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The thesis is divided into two sections. Part I, a literature review, covers the methods available for the measurement of biological nitrogen fixation by legumes, but concentrates on the advantages and disadvantages of the acetylene reduction method, and also the factors which limit nitrogen fixation by legumes. Part II covers the experimental work, the results and conclusions. Acetylene reduction methods of measuring nitrogen fixation by white clover in pots and field cores of red and white clover were tested and a suitable method for regular routine assays was developed. The results from this work stressed the importance of establishing optimum procedures prior to routine sampling and to standardize sampling end incubation procedures to allow for comparative work between sites and treatments. A series of pot experiments were set up to investigate the effects of Mo, Co and Cu treatment on white clover grown in soil deficient in these elements. Little treatment response in terms of nitrogen fixation, dry matter yields or plant-N content was found. The results of field work during 1976 and 1977 showed the marked difference in magnitude end patterns of acetylene reduction activity of both red and white clover grown on upland and lowland sites, the effects of different varieties of white clover, the effects of fertilizer treatment and periodic defoliation. Estimates of total nitrogen fixed from the white clover sites were made but the difficulties in using acetylene reduction results for such estimates are stressed. The implications of the field results in the use of pasture legumes is discussed in the final conclusions.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available