Growth and Yield Responses to Mulches and Cover Crops under Low Potassium Conditions in Drip-irrigated Apple Orchards on Coarse Soils
Bibliographic record
Abstract
Fertigated ‘Gala’ apple trees on M.9 ( Malus domestica Borkh.) rootstock, planted in 1998, were grown on a coarse soil for 6 years (1998 to 2003) and exposed to eight orchard floor vegetation management treatments within the tree row. These consisted of a glyphosate control; three waste paper mulch treatments [spray-on mulch paper mulch (SM), SM incorporated with dichlobenil, SM applied over uniformly spread shredded office paper (SOP)]; and four living cover crop mulch treatments [dwarf white clover (WC), sweet clover (SC), hairy vetch (HV), and annual rye]. There were no significant treatment effects on leaf nitrogen (N) and phosphorus (P) status; however, leaf potassium (K) levels were negatively affected by the living mulch treatments in 2 of 5 years. Tree vigor was diminished by several of the orchard floor vegetation management systems in 5 of 6 years. Trees receiving an SM treatment grew more rapidly than trees receiving the ground cover treatments and trees receiving a glyphosate treatment had relatively poor but comparable growth to several of the cover crop treatments. Growth response in trees receiving SM were observed in all production years. After 6 years, cumulative yields were highest from trees receiving any of the three SM or glyphosate treatments and significantly less for any of the ground cover treatments. Weed growth within the rye cover crop was significantly reduced in comparison with the other living mulches; however, it remained sufficiently competitive to contribute to diminished overall yield and tree growth in comparison with the SM and gylphosate control treatments. Overall, response of leaf K concentration to mulch treatments was insufficient to prevent low K levels after 5 years. The addition of K through the organic mulches or recycling of K by cover crops was insufficient to avoid the development of low leaf K levels. Annual fertigation of K, in addition to N and P, appears necessary to maintain adequate vigor and yield when using mulches or cover crops in intensive, drip-irrigated apple orchards grown on coarse soils.
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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 | 0.000 | 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) | 0.001 | 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".