Nitrogen Mineralization Potential (No) in Three Kenyan Soils: Andosls, Ferralsols and Luvisols
Bibliographic record
Abstract
Nitrogen mineralization potential is important so as to prevent over-fertilization that could lead to groundwater contamination or under-fertilization that could lead to poor nutrient provision by crops leading to low yields. Three soil types were selected on the basis of groups, agro-ecological zone, organic matter content and land use. The soil samples were taken from the 0-15 and 15-30 cm depth. The samples were placed in incubation bags, water added to field capacity, sealed and incubated in laboratory at room temperature. The bags were opened at intervals of two weeks and soil sub-samples taken for analysis of mineral N for a period of 17 weeks. The calculated mineralizable N was 138.8 μg N and 116.4 μg N/g for Gituamba andosols, 46.0 μg N and 46.4 μg N/g for Kitale ferralsol and 260.1 μg N and 197.3 μg N/g soil for Katumani luvisols in the 0-15 and 15-30 cm depth, respectively. These calculated values compared well with the actual cumulative mineralizable N for Gituamba andosols at 127 μg N and 74.1 μg N/g, for Kitale ferralsols at 48.0 μg N and 64.1 μg N/g and for Katumani 80.6 μg N and 47.7 μg N/g soil in the 0-15 and 15-30 cm depth, respectively. The time taken for 50% of potentially mineralizable N to be mineralized (t½) ranged from 6.3 weeks for Katumani luvisols 15-30 cm to 30.1 weeks for Kitale ferralsols 0-15 cm soil depths. The soils with highest rate constant (k) had the least. For example, 15-30 cm depth of Katumani luvisols with of 6.3 weeks had the highest k of 0.112 week-1 compared with Kitale ferralsols 0-15 cm depth with t½ of 30.1 weeks and the lowest k of 0.023 week-1. The observed data indicates that 50% of N would be mineralized in all the soil types with the exception of Kitale ferralsols (0-15 cm depth) within the growing period of the crops which is approximately 20 weeks.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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) | 0.001 | 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".