Thesis (Ph. D.)--University of Adelaide, Dept of Plant Pathology, 1985. / Includes bibliographical references (leaves 214-221).

No description available.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Mar. 5, 2009). PDF text: xv, 192 p. : ill. ; 15 Mb. UMI publication number: AAT 3336552. Includes bibliographical references. Also available in microfilm and microfiche formats.

No description available.

Thesis (M.S.)--Oregon State University, 1982. / Typescript (photocopy). Includes bibliographical references (leaves 80-83). Also available on the World Wide Web.

Thesis (Ph.D.)--University of Adelaide, Faculty of Agricultural Science, 1958. / Includes bibliographical references.

Thesis--University of Wisconsin. / Supported in part by Environmental Science Services Administration, grant E-287-68(G).

Plant roots are central to C- and N-cycling in soil. However, (i) plants differ strongly in tissue recalcitrance (e.g. lignin content) affecting their mineralization in soil, and (ii) rhizodeposits also vary strongly in terms of the metabolites that they contain. Therefore, (i) we used 13C labelled ryegrass root and shoot residues as substrates to investigate the impact of tissue recalcitrance on soil processes through controlled incubation of soil, (ii) we assessed variations in root C-deposition between barley genotypes and their respective impacts on soil processes using 13CO2 labelled plants, (iii) using 13C/15N enriched ryegrass root residues as tracer material, we investigated the impacts of barley genotypes on mineralization of recently incorporated plant residues in soil and plant uptake of the residue-derived N, and (iv) we applied a quantitative trait loci analysis approach to identify barley chromosome regions affecting soil microbial biomass and other soil and root related traits. In the first study, addition of root residues resulted in reduced C-mineralization rates, soil microbial activity and soil organic matter (SOM) priming relative to shoot residues. Planted experiments revealed (i) genotype effects on plant-, SOM- and residuederived surface soil CO2-C efflux and showed that incorporation of plant derived-C to the silt-and-clay soil fraction varied between genotypes, indicating relative stabilization of root derived-C as a result of barley genotype, (ii) that plant uptake of residue released N between genotypes was linked to genotype impacts on residue mineralization, and (iii) barley chromosome regions that influence plant-derived microbial biomass C. These results (i) suggest that greater plant tissue recalcitrance can lower soil C-emissions and increase C-storage in soil, and (ii) demonstrate the barley genetic influence on soil microbial communities and C- and N-cycling, which could be useful in crop breeding to improve soil microbial interactions, and thus promote sustainable crop production systems.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 75-81). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 75-81). Also available on the Internet.