Influence of six successive annual applications of sulphur fertilizers on wheat in a wheat–canola rotation on a sulphur deficient soil
Bibliographic record
Abstract
A 9-yr (1999–2007) field experiment was conducted on a S-deficient Gray Luvisol (Typic Cryoboralf) loam soil at Porcupine Plain in northeastern Saskatchewan. The objective was to compare the influence of six successive annual applications (1999–2004) and the following residual effects for 3 yr (2005–2007) of elemental S and sulphate-S fertilizers on yield, seed protein and total S concentration, and S uptake of wheat (Triticum aestivum L.) in a wheat–canola rotation. Treatments used were combinations of two application times (preceding autumn and before seeding in spring) with two granular elemental S fertilizers (ES-90 and ES-95), one fertilizer containing both elemental S and sulphate-S (Agrium Plus), ammonium sulphate, and a zero-S control. The S fertilizers were applied annually at a rate of 15 kg S ha–1. From 1999 to 2004, seed yield (3 yr) and straw yield (4 yr), seed protein concentration (3 yr), total S concentration in seed (4 yr), and S uptake in seed (5 yr) and straw (5 yr) of wheat showed significant response to S fertilization. In the first year (1999), ammonium sulphate and Agrium Plus were more effective than ES-90 and ES-95. In the following years (2000–2004), there was no significant effect of S source on seed and straw yield. Sulphate-S containing fertilizers produced greater total S concentration in seed and S uptake in straw (3 yr) and for S uptake in seed (1 yr). There was no effect of timing of S application on seed yield and protein concentration in any year, but autumn application was superior to spring application for straw yield and S uptake (1 yr), and for seed total S concentration and S uptake (2 yr). Residual effects of six previous S applications showed improvement in wheat seed yield until 2006, and straw yield and total S uptake until 2007. Elemental S, especially when applied in autumn, tended to have more lasting residual effects than the other S fertilizer treatments. There was some build-up of residual sulphate-S in soil in almost all S fertilizer treatments after four successive applications, but this was generally higher with sulphate-S-containing fertilizers. Recovery of applied S from 1999 to 2004 in plants was usually higher with sulphate-S fertilizer than with elemental S fertilizer in most years. Recovery of applied S in soil was higher for sulphate-S fertilizers, followed by ES-90, and finally ES-95. Residual nitrate-N in soil was significantly lower in spring-applied ammonium sulphate treatment than the zero-S or other S treatments. Key words: Elemental S, fertilizer, protein concentration, S uptake, sulphate-S, wheat, yield
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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 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".