Solute transport in a hummocky landscape: I. Two-dimensional redistribution of bromide
Bibliographic record
Abstract
Olatuyi, S. O., Akinremi, O. O., Flaten, D. N. and Lobb, D. A. 2012. Solute transport in a hummocky landscape: I. Two-dimensional redistribution of bromide. Can. J. Soil Sci. 92: 609-629. Bromide has been widely used in field studies to estimate nitrate leaching in agricultural soils. This study examined the impacts of crop response to nitrogen fertilization on the vertical and lateral redistribution of bromide in the fall and spring seasons in a hummocky landscape. The study was carried out near Brandon, Manitoba, in 2007 and 2008, using two separate plots (Site-2007 and Site-2008). The plots were delineated into three landscape positions as upper (UPP), middle (MID) and lower (LOW) slope. A microplot at each landscape position received 15N labelled fertilizer (KNO3) at the rates of 0, 90 and 135 kg N ha-1, and KBr at the rate of 200 kg Br- ha-1. Site-2007 was seeded to canola while Site-2008 was seeded to winter wheat. Soil samples were taken within the microplot to a depth of 120 cm for vertical distribution, and up to 200 cm away from the microplot for lateral distribution of Br- in the top 20 cm depth. The downward movement of Br- in the soil was reduced under N fertilization. This resulted in the accumulation of Br- in fertilized plots, and a greater lateral movement of Br- in fertilized compared with unfertilized plots. The greatest vertical and lateral movement of Br- occurred at the LOW slope position. In the fall season following Br- application, 55 and 15% of the Br- applied were recovered in the vertical and lateral components of the landscape, respectively. Estimated loss of Br- due to vertical and lateral movement was 47% in the unfertilized treatment and 36% with N fertilization. The order of Br- loss in the two dimensions was: LOW (48%)>MID (40%)>UPP (37%). The study shows that crop response to N fertilization reduced the vertical movement of solute, thereby providing an experimental support for the “Campbell hypothesis”which states that N fertilization and proper rate of N application reduces nitrate leaching.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".