NITRATE LEVELS IN TILE DRAINAGE WATER OF FERTILIZED AND UNFERTILIZED FIELD PLOTS
Bibliographic record
Abstract
Nitrate levels in precipitation and in tile effluents were monitored on a pair of field plots to document the status ofinput from precipitation and soil fertility. The field plots with imperfect drained Concestoga silt loam soil wereestablished in Elora Research Station of the University of Guelph. The plots were kept under grass with zero inputof nitrogen (fertilizer or manure) for the more than five years. Nitrate concentration monitoring began in April 1997and throughout 2000. Herbicide of Round Up (1:2, dicamba:atrazine) was applied at 7 L/ha to both plots on April 272000 to control weeds. Both plots were planted with corn (Zea mays L.), Pioneer 3905, on May 31, 2000 under no-tillpractices. Fertilizer (12.5-100-80 (kg/ha), N-P-K) was applied incorporated to the seed rows on one plot (W3)while the other plot (W4) was unfertilized. Side dressing of 28% (28 mg/L nitrate/ha ) of urea ammonia nitrate mixedwith water was banded applied at 165L/ha) to the corn row of the W3 on July 5, 2000. The average nitrateconcentration for precipitation, W3 and W4 from April 1997 to May 2000 prior to W3 fertilization, respectively, were1.031, 0.123 and 0.116 mg/L and the average nitrate concentration in precipitation, W3 and W4 tile flows from Juneto December 2000 after fertilization on W3 respectively, were 0.546, 1.558 and 0.209 mg/L.. The cumulative nitrateloss of 0.47 kg/ha for W3 from April 1997 to May 2000 compared to 0.44 kg/ha for W4 of same period almostequal, and the precipitation input over the same period was 19.5 kg/ha indicating that nitrate losses from W3 andW4 were practically contributed from precipitation input. In contrast, cumulated nitrate loss of 2.75 kg/ha for W3from June to December 2000 was 91% higher compared to 0.241 kg/ha for W4 of the same period. The nitrate inputfrom precipitation of 3.26 kg/ha over the same period was comparable to the nitrate loss from W3 plot, indicatingthat the nitrate loss from W3 plot virtually was contributed by applied fertilizer.The influence of nitrogen fertilizer on corn physiological development and yield were investigated. The length andwidth of leaf and size of stem measured on W3 plot with fertilizer input of 12.5 kg N/ha plus side dressing of 6.3 kgN/ha of Urea ammonia, showed about 20% (37% for stem height) larger than the unfertilized plot, W4.The overallaverage yield of stalk and cob by weight were 53% higher for W3 compared to W4.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".