Investigating red clover (Trifolium pratense L.) stand survival and uniformity when under-seeded to winter wheat (Triticum aestivum L. em. Thell) under low soil moisture
Bibliographic record
Abstract
Red clover (Trifolium pratense L.), when included in corn (Zea mays)-soybean (Glycine max)-winter wheat (Triticum aestivum L. em. Thell) rotations in relay cropping with winter wheat, has been shown to increase organic matter, soil tilth, yield and productivity of the rotation and to decrease soil erosion, nitrate leaching and synthetic nitrogen fertilizer requirements. In spite of these benefits, red clover inclusion into crop rotation has declined, largely due to non-uniformity of red clover stands. In Ontario, causes of heterogeneous red clover stands have not been conclusively determined although the effects of tillage and shifts in competition for light and nutrients between wheat and clover during relay cropping have been investigated. As suggested by the high year effect across those studies, variation in soil moisture during relay cropping likely has a large effect on red clover stand uniformity. We conducted a field experiment repeated over three years to test the impact of different soil moisture deficits on the establishment of clover varieties with different growth habits (single-cut and double-cut). Low soil moisture, beginning either late May or late June, under winter wheat decreased red clover stand densities and above-ground biomass. A second field experiment more specifically examined the effect of water exclusion on red clover stand uniformity over a large area under irrigated and non-irrigated conditions. In 2015, low soil moisture in spring increased stand non-uniformity in non-irrigated plots. Differences between varieties in response to drought and drought tolerance mechanisms were investigated in growth room studies. The double-cut variety Belle had greater leaf area and shoot water content during mild to moderate drought conditions compared to the single-cut variety Altaswede. In contrast, Altaswede had significantly higher survival rates than Belle after moderate to severe drought stress. Differences in drought response and recovery were also observed between other single-cut and double-cut varieties. By demonstrating that red clover growth and stand uniformity can be impacted by drought mechanisms, effective strategies for the development of improved varieties through breeding or screening efforts can be identified.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".