Influence of residual manure on selected nutrient elements and microbial composition of soil under long-term crop rotation
Bibliographic record
Abstract
A study was conducted on a long-term field experiment at the University of Pretoria, South Africa, that was established in 1939. The aim was to investigate the effects of residual manure on the characteristics of the total and microbial biomass and their nutrient contents in the soil and on maize yield under long-term crop rotation. It was found that total C, N and available P levels were increased as a result of manure application. Seasonally, these nutrients exhibited variations that appeared to be related to influences of crop rotation. Long-term soil N content in an adjacent native site remained relatively constant while it tended to increase in the control and manured plots. Soil microbial biomass content of C, N, and P and microbial populations were affected by previous manure application, as well as by crop rotation. The biomass and numbers of microflora were generally higher in the manured plots. Manure application also resulted in higher maize yields and had substantial residual effects. Relationships between the different soil properties considered and crop yield are presented and their implications discussed.
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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 | 0.001 |
| 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 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".