[ { "factor_id": "barley-n-rate", "crop_id": "barley", "factor": "Nitrogen management for malt vs feed barley", "factor_category": "Nutrients", "direction": "positive", "effect_type": "yield_gain", "effect_size": 21.4, "effect_unit": "%", "ci_lower": 15.0, "ci_upper": 28.0, "conditions": "Balanced N rate (70-100 kg N/ha for malt to cap protein <12.5%; 100-140 kg N/ha for feed barley) under rainfed Prairie conditions.", "study_count": 29, "evidence_type": "field_trial", "evidence_strength": "High", "prairie_relevance": "high", "source_title": "Nitrogen fertilizer management effects on malting barley yield, quality, and economic returns", "source_url": "https://doi.org/10.4141/cjps06014", "notes": "Excessive N increases lodging and pushes grain protein over malting selection thresholds (11.0-12.5%).", "potential_yield_effect": 21.4 }, { "factor_id": "barley-seeding-rate", "crop_id": "barley", "factor": "Seeding rate and stand density (250-325 plants/m2)", "factor_category": "Crop establishment", "direction": "positive", "effect_type": "yield_gain", "effect_size": 12.8, "effect_unit": "%", "ci_lower": 8.0, "ci_upper": 17.5, "conditions": "Seeding to establish 250-325 plants/m2 (23-30 plants/ft2) in early spring into cold seedbeds.", "study_count": 20, "evidence_type": "field_trial", "evidence_strength": "High", "prairie_relevance": "high", "source_title": "Optimizing malting barley seeding rates and plant populations across Western Canada", "source_url": "https://doi.org/10.4141/cjps2013-112", "notes": "Higher plant density promotes uniform kernel plumpness (>85% on 6/64 sieve) and reduces tiller variation.", "potential_yield_effect": 12.8 }, { "factor_id": "barley-biostimulant-seaweed-humic", "crop_id": "barley", "factor": "Biostimulants: Seaweed extract and humic acid foliar blends", "factor_category": "Biostimulants", "direction": "positive", "effect_type": "yield_gain", "effect_size": 10.5, "effect_unit": "%", "ci_lower": 6.0, "ci_upper": 15.0, "conditions": "Foliar application at tillering (Zadoks 22-25) and stem elongation (Zadoks 31) under dryland Prairie moisture stress.", "study_count": 14, "evidence_type": "field_trial", "evidence_strength": "Moderate", "prairie_relevance": "moderate", "source_title": "Seaweed extracts and humic substances improve barley drought tolerance and grain yield", "source_url": "https://doi.org/10.1016/j.agwat.2021.107021", "notes": "Increases chlorophyll retention, root surface area, and proline accumulation during mid-season dry spells.", "potential_yield_effect": 10.5 }, { "factor_id": "barley-pgpr-inoculation", "crop_id": "barley", "factor": "Biological inputs: Endophytic and rhizospheric PGPR inoculation", "factor_category": "Biological inputs", "direction": "positive", "effect_type": "yield_gain", "effect_size": 9.2, "effect_unit": "%", "ci_lower": 5.0, "ci_upper": 13.5, "conditions": "Seed treatment with Bacillus subtilis and Pseudomonas putida in low-organic matter soils.", "study_count": 15, "evidence_type": "field_trial", "evidence_strength": "Moderate", "prairie_relevance": "high", "source_title": "Plant growth-promoting rhizobacteria inoculation enhances phosphorus mobilization and yield in Hordeum vulgare", "source_url": "https://doi.org/10.1007/s00374-020-01502-3", "notes": "Produces siderophores and organic acids that solubilize fixed soil phosphates.", "potential_yield_effect": 9.2 }, { "factor_id": "barley-foliar-fungicide", "crop_id": "barley", "factor": "Foliar fungicide timing for scald and net blotch", "factor_category": "Disease management", "direction": "positive", "effect_type": "yield_gain", "effect_size": 15.2, "effect_unit": "%", "ci_lower": 10.0, "ci_upper": 20.5, "conditions": "Application of dual-mode strobilurin/triazole fungicide at flag leaf emergence (Zadoks 39-45) under moderate-to-high disease pressure.", "study_count": 27, "evidence_type": "field_trial", "evidence_strength": "High", "prairie_relevance": "high", "source_title": "Control of foliar leaf spot diseases and yield response in Canadian Prairie barley", "source_url": "https://doi.org/10.4141/cjps99-041", "notes": "Protects flag and penultimate leaves; maintains high test weight and plumpness essential for malt acceptance.", "potential_yield_effect": 15.2 }, { "factor_id": "barley-drought-heat-stress", "crop_id": "barley", "factor": "Heat and moisture stress during heading and grain filling", "factor_category": "Stress", "direction": "negative", "effect_type": "yield_loss", "effect_size": -24.0, "effect_unit": "%", "ci_lower": -34.0, "ci_upper": -15.0, "conditions": "Drought stress coinciding with temperatures >30°C from heading through soft dough stages.", "study_count": 22, "evidence_type": "review", "evidence_strength": "High", "prairie_relevance": "high", "source_title": "Physiological responses of barley genotypes to heat and drought stress during grain development", "source_url": "https://doi.org/10.1016/j.jcs.2017.03.011", "notes": "Reduces kernel weight, increases thin grain percentage (>10% thins causes malt rejection), and spikes protein.", "potential_yield_effect": -24.0 }, { "factor_id": "barley-organic-malting-feed-premium", "crop_id": "barley", "factor": "Certification & Profitability: Certified Organic feed & craft malt price premium", "factor_category": "Economics & Certification", "direction": "positive", "effect_type": "price_premium", "effect_size": 85.0, "effect_unit": "% premium", "ci_lower": 65.0, "ci_upper": 115.0, "conditions": "Certified organic feed barley commands $10.00–$14.50/bu and organic craft malting barley $14.00–$18.50/bu compared to conventional baseline of $5.50–$7.50/bu (+65% to +115% premium).", "study_count": 13, "evidence_type": "economic_benchmark", "evidence_strength": "High", "prairie_relevance": "high", "source_title": "Manitoba Agriculture Organic Cost of Production & Alberta Organic Feed Grain Benchmarks", "source_url": "https://www.gov.mb.ca/agriculture/farm-management/production-economics/cost-of-production.html", "notes": "Organic barley fits well into organic rotations as an early-seeded competitive crop that suppresses annual weeds. Organic yield discount is 15-25%, yielding +35% to +70% higher gross margins per acre under livestock feed and craft brewing contracts.", "potential_yield_effect": -20.0 } ]