Silicon increases wheat grain yield under field stress: reproducibility package (data, code, prompts, audit ledgers)

Reproducibility package supporting the manuscript "Silicon increases wheat grain yield under field stress: a human-reviewed, LLM-assisted meta-analysis" (Halpern, 2026; submitted to Agronomy for Sustainable Development). Contents: final extraction datasets, analysis inputs, dual-pipeline LLM extraction outputs, contrast-rescue ledger, audit ledgers and citation audit, prompt inventory and run metadata, analysis scripts, and the rebuilt manuscript review draft. Source PDFs of the included primary studies are excluded from this public package for copyright reasons; a separate internal audit package retaining the PDFs is held privately for traceability and will not be redistributed. Primary result: silicon increased wheat grain yield by +11.35% (95% CI +7.49% to +15.34%; 257 comparisons from 30 studies) under field conditions, with the largest effects under salinity (+36.0%, k=18, 4 studies) and drought (+13.4%, k=58, 9 studies). The estimator is a three-level method-of-moments random-effects model with CR2 cluster-robust variance and Tipton-HTZ degrees of freedom; details and reproduction scripts are inside the package. Companion preprint: https://doi.org/10.64898/2026.02.17.706322.