Barley yield and nutrient uptake in rotation after perennial forages in the semiarid prairie region of Saskatchewan
Bibliographic record
Abstract
Jefferson, P. G., Selles, F., Zentner, R. P., Lemke, R. and Muri, R. B. 2013. Barley yield and nutrient uptake in rotation after perennial forages in the semiarid prairie region of Saskatchewan. Can. J. Plant Sci. 93: 809-816. Alfalfa (Medicago sativa L.) is the most common perennial forage legume grown for hay and pasture in the semiarid Brown soil zone of the Canadian prairies. Perennial forages often are not recommended for inclusion in annual crop rotations due to lower grain yields and drier soils following forage stand termination, but this is based on research results from 50 yr ago. Three replicated experiments consisting of three grasses [slender wheatgrass (Elymus tracycaulus), intermediate wheatgrass (Elytrigia intermedia), and Dahurian wildrye (Elymus dahuricus)] grown in monoculture and in mixture with two alfalfa varieties (cv. Beaver or cv. Nitro) were terminated and seeded to barley (Hordeum vulgare ‘Harrington’) for 2 consecutive crop years at Swift Current, Saskatchewan. Soil water content was lower after the alfalfa-grass mixtures compared with the grass monocultures, even during a wet growing season. Barley yield and N concentration in the grain were significantly greater following Beaver alfalfa/grass mixture compared with grass monoculture in 3 and 4 of 6 site years, respectively. N uptake by the barley crop (grain and straw) was also significantly greater following Beaver alfalfa/grass mixture than following grass monoculture in all 6 yr. Both barley grain yield and N uptake after intermediate wheatgrass (grown in monoculture) were lower than after Dahurian wildrye or slender wheatgrass in 3 of 6 yr. The use of alfalfa and a short-lived grass species in hay and pasture mixtures in the Brown soil zone when grown in rotation with annual crops may indeed result in lower grain yields in the short term than continuous annual cropping systems, but the inclusion of alfalfa will provide a N benefit to the subsequent grain crop thereby enhancing yield and possibly its market value.
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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".