Record Details
Nodulation problems with alfalfa and subterranean clover on selected Oregon soils
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Nodulation problems with alfalfa and subterranean clover on selected Oregon soils |
| Names |
Attavirojana, Pitsanu
(creator) Dawson, M. D. (advisor) |
| Date Issued | 1968-12-20 (iso8601) |
| Note | Graduation date: 1969 |
| Abstract | Two separate investigations were carried out. The first experiment on subterranean clover (Mr. Barker) was conducted in the field and greenhouse on the Steiwer soil. The second experiment on alfalfa (DuPuits) was conducted in the greenhouse on selected eastern Oregon soils. The purposes of the first experiment were to determine the growth response of subterranean clover as influenced by different levels of applied N-S-S, and to examine the performance of subterranean clover inoculated with three different rhizobia strains. In experiment I, Rhizobium strains TS-1, TA-1 and NZ-29 were used to inoculate subterranean clover. The fertilizer treatments included two levels of applied phosphate and sulfate fertilizer (20 pounds and 80 pounds P₂O₅/acre; 10 pounds and 40 pounds S/acre) both with and without applied nitrogen (33 pounds and 66 pounds N/ acre). Treatments in the greenhouse and field trials were similar. There were no significant differences between subterranean clover yields inoculated in turn with each of the rhizobia. strains. Results from the field trial indicated subterranean clover yield increase due to the highest rates of applied phosphate and sulfate (80 pounds P₂O₅/acre and 40 pounds S/acre over the 20 pounds P₂O₅/acre and 10 pounds S/acre) were not statistically significant. The number of effective nodules decreased with the addition of nitrogen fertilizer, while nitrogen applications did not significantly influence subterranean clover yield. No significant difference in subterranean clover yield resulting from inoculation with either rhizobia strain (TS-1, TA-1 and NZ-29) was shown in the greenhouse experiment. There was a highly significant response to phosphate and sulfate applied at rates equivalent to 80 pounds P₂O /acre and 40 pounds S/acre over the 40 pounds P₂O₅/acre and 10 pounds S/acre. Nitrogen application did not significantly increase subterranean clover yield. The purpose of the second experiment was to determine the Ritsal agents responsible for "sick alfalfa" in selected Oregon soils. Inoculated and non-inoculated alfalfa was grown in the greenhouse in both sterilized and unsterilized soil with and without applied nitrogen. Both dry matter yield (grams/pot) and nodule characteristics were observed. Alfalfa responded significantly to inoculation on sterilized soil absence of applied nitrogen on four of the seven soils studied. In contrast, there was no significant increase in alfalfa yield resulting from inoculation of plants grown on the unsterilized soil. However, alfalfa yield increased significantly when nitrogen was applied to inoculated plants grown in unsterilized soil. The laboratory investigations indicated that there were antagonists (likely bacteria and actinomycetes) which inhibited the inoculated Rhizobium meliloti strains in agar, in all seven studied soils. Slight yellowing of the leaves and slight reduction in the amount of alfalfa growth were observed in the testing of antagonists for ability to inhibit nodulation of alfalfa grown under sterile conditions. These symptoms suggested inhibited symbiosis. A plausible explanation for the "sick alfalfa" condition observed in plants growing in the field on these soils is offered. |
| Genre | Thesis/Dissertation |
| Topic | Subterranean clover |
| Identifier | http://hdl.handle.net/1957/46477 |
