Record Details
Effects of residual and applied nitrogen on Nugaines wheat
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Effects of residual and applied nitrogen on Nugaines wheat |
| Names |
Laopirojana, Pojanee
(creator) Roberts, Steve (advisor) |
| Date Issued | 1969-12-12 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | A study was made to evaluate the effect of different rates of N fertilization on Nugaines wheat. The variable N treatments provided different N regimes as a basis for evaluating potential diagnostic tests for assessing the N status of the wheat plant. The crop was grown in Lane county during the 1968 growing season on soil of the Malabon. series. To evaluate the treatment effects the yield of grain and dry matter, number of culms per foot of drill-row, leaf percentage, grain protein, test weight, and concentration and uptake of nutrients (N, P, K, Ca and Mg) were measured. The preliminary evaluation of the diagnostic tests for assessing the N status of the wheat plant were conducted by comparing the relative sensitivity of the above parameters to the different rates of applied N. First approximations of the critical levels were estimated from graphs of grain yield against the various analytical measurements. The application of N increased grain yield, dry matter production, the concentration of nitrate-N, N, P and K in the plant tops. The application of 200 pounds of N per acre decreased the test weight and increased the protein content of the grain. This same rate of N fertilization produced an increase in the number of culms per foot of drill-row and the plant leaf percentage. The concentration of nitrate-N, total N, P, K, Ca, and Mg in the plant tops decreased with time irrespective of N treatment as the plants matured. The concentration of nitrate-N in the upper leaves was greater than the concentration of nitrate-N in the lower leaves at the boot stage of growth. The total uptake of these nutrients with time corresponded to increases in yield of dry matter. A suitable approach for assessing the N status of the wheat plant appeared to be that of measuring the level of total N in the plant tops or the level of nitrate-N in the plant leaves during the latter part of April. At this time the critical level for total N in the plant tops was about 2.8% and the critical level for nitrate-N in the plant leaves was about 300 parts per million. Greater precision was attained in the measurement of total N concentration in plant tops than for the concentration of nitrate-N in the leaves. The critical-level approach for dry matter production, culms per foot of drill-row, and leaf percentage appeared to have limited value for assessing the N status of the wheat plant. |
| Genre | Thesis/Dissertation |
| Topic | Soils -- Nitrogen content |
| Identifier | http://hdl.handle.net/1957/46228 |
