No description available.

The responses of two cowpea (Vigna unguiculata (L.) Walp.) cultivars inoculated with granular inoculum (a mixture of rhizobia) at different levels of applied nitrogen were evaluated. California Blackeye 5 (Ca5) and Knuckle Purple Hull (KPH) cowpeas were examined under field conditions for percent nodulation, nodule number, and nodule mass per plant, and nitrogenase activity at various times during the 1983 and 1984 growing seasons. Data were also obtained for shoot and root dry weights, seed yield, and protein content. Significant differences between inoculated and uninoculated plots were found at all nitrogen treatments for both cultivars with respect to nodulation percentage, nodule number, nodule mass, and nitrogenase activity. An inverse trend linear and quadratic was noted between nitrogen increments and nodulation (nodule number and nodule mass) of Ca5 and KPH cowpeas. High N (168 kg N ha('-1)) was more inhibitory to nodulation than low (28 kg N ha('-1)) N applied. Nitrogenase activity of both cultivars was significantly stimulated with low and inhibited by high levels of ammonium nitrate. Effects of nitrogen treatments on nodulation and nitrogenase activity were influenced by the stage of growth and cowpea cultivar. At the pod-fill stage, higher nodule numbers and nitrogenase activity were recorded for Ca5 as compared to KPH cowpeas. Morphological differences, with Ca5 plants being erect with few vines, whereas KPH plants were semi-erect and bushy, were observed between inoculated and uninoculated plants of Ca5 and KPH cowpeas at all levels of applied nitrogen. Dry weights of vegetative components of both cultivars were significantly improved when low (28 kg N ha('-1)) rather than high (168 kg N ha('-1)) nitrogen was added. Inoculation significantly increased seed yield of Ca5 cowpeas. When conditions were favorable seed yield of inoculated Ca5 exceeded that of inoculated KPH in all comparisons within the same increments of applied N. Seed yield of both cultivars was adversely affected when high levels of nitrogen were applied. Seed, leaf, petiole, and stem protein content were significantly higher with respect to inoculated than uninoculated plots. However, nitrogen fertilizers tended to decrease protein content of the measured parameters for Ca5 and KPH cowpeas.

No description available.

No description available.

The role of Beijerinckia spa and Klebsiella spp in stream litter decomposition was investigated using acetylene reduction method. Beijerinckia and Klebsiella were isolated during the winter and spring of 1980, from the leaves of sugar maple (Acer Saccharum), placed in Bell Creek, Muncie, Indiana. A nitrogen-free media was used to isolate Klebsiella. Both of these organisms were streaked separately on nitrogen-free agar slant tubes, flushed with argon and acetylene added. Gas chromatographic analysis were conducted on the innoculated tubes after incubation for 24 hours at 320 C. Beijerinckia spp, isolated from January, February, and April fixed between 4.48 x 10-7 moles and Klebsiella spp isolated during the same time period was between 1.47 to 8.10 x 10-8 moles. This study indicates that Beijerinckia is a better N2 fixer than Klebsiella in stream litter decomposition.

Thesis (M.S. - Agricultural and Resource Economics)--University of Arizona. / Includes bibliographical references (leaves 145-152).

Thesis (doctoral)--University of Tartu, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1960. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Nitrogen oxides control the global formation of ozone in the lower atmosphere and influence the much higher levels of ozone formed in areas subjected to photochemical air pollution. As an important member of the nitrogen oxide family, N02 plays a significant role in serving as the only known source of ozone (through photolysis) in the lower atmosphere and as sink for HO via the formation of nitric acid. Ozone can be destroyed by reaction with another member of the nitrogen oxide family, nitric oxide (NO), to reform N02. This cycle between NO, N02 and 03 is known as the NOx-03 photostationary state (PSS). Imbalances in this cycle have been used to calculate ambient levels of oxidants (such as R02 and H02) responsible for ozone production. Consequently, accurate N02 measurements are critical to making meaningful measurements of the imbalances in the NOx-03 photostationary states (PSS). A low pressure laser-excited fluorescence technique (FAGE) for the direct determination of atmospheric N02 has been developed. This technique has been explored with both a Nd-YAG laser (1.4 W, 532nm, 30Hz) and a Cu-vapor (1.2 W, 511nm, 5.6kHz) laser. The detection limits for these instruments, under laboratory conditions and a signal collection time of 20s (lOs each signal and background), have been determined to be 450 and 350pptv N02, respectively. In these systems, the background was measured by chemically reducing N02 with FeS04°7H20. Ambient measurements of the NOx-03 photostationary state (PSS) were undertaken on a rooftop monitoring site in downtown Portland, Oregon. N02 was monitored with the Cu-vapor system. Nitric oxide and ozone were monitored with standard instruments. Data for three days in 1990 are presented. Overall these data sets clearly show that despite daily changes in concentration of NO, N02 and 0 3 of factors of 4-10 each, the PSS remains relatively constant to within -50%. This is in itself strong confIrmation of the primary importance of the NOx-03 photo stationary state in controlling the concentrations of these species at these levels. In addition, these experiments also serve to demonstrate that the monitoring instruments, including FAGE-N02, are not subject to serious interferences or artifacts at these concentration levels.