No description available.

No description available.

6 pp. / Lisbon lemons were treated with N levels ranging from 0.5 to 3.0 lbs. N per tree annually. Fourth–season yield results from the trial show significant effects of the treatments upon overall yield and leaf N concentrations, but no effect upon fruit packout. Treatments did lead to a significant effect upon leaf nutrient concentration. Total cumulative yields from 2008 to 2012 (not including the freeze-affected 2011-12 season) were significantly affected by the treatments. Trees treated annually with 2.0 lbs N had the greatest yield, which represented a 12% increase over the yield of trees treated with just 0.5 lbs. N annually.

Knowledge of the relationships between nitrogen fertilization and nitrogen availability is needed to guide plans for providing optimum tree growth by silvicultural operations. PART 1. Detailed studies of the mineralization of urea were made by laboratory incubation of black spruce humus samples. These studies form a part of an experiment in which urea is used for the first time to fertilize a soil supporting a black spruce stand. Urea seems to be a very good fertilizer because it is readily transformed to an available form of nitrogen. It is however doubtful that a nitrogen fertilization only could quickly and greatly affect the humus fertility. PART 2. Total number and number of ureolytic bacteria and fungi were determined at time intervals during a laboratory incubation of black sprucc humus samples. Such a quantitative and qualitative study of the microbial population of a raw humus had never been made. The potential for ureolysis is enormous because this humus contains an abundance of ureolyzing microorganisms Indeed, counts in excess of 100 millions per gram are not uncommon.

No description available.

No description available.

xiv, 173 leaves : graphs, tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1979) from the Dept. of Agronomy, University of Adelaide

Thesis (Ph.D.)--Tufts University, 1999. / Adviser: Sara M. Lewis. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 155-171). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2001. / Härtill 6 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.