[
  {
    "element_id": "hops-n-rate-chinook-lagos-2023",
    "crop_id": "hops",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen rate 250 kg N ha−1 (urea, split) vs 0 N",
    "claimed_effect": "cone dry matter 386.7 kg ha−1 at 250 kg N ha−1 vs 245.8 kg ha−1 at 0 N; linear increase in cone number, cone/leaf/branch DM, and oil yield per plant",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilized control (0 N)",
    "study_context": "cv. Chinook; field, Guarapuava-PR, Brazil; three harvests 2018/19–2020/21; urea 46% split at BBCH 1/2/3; max photoperiod 13.8 h; yields below IHGC world-producer mean",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1590/0034-737X202370050009",
    "source_citation": "Lagos, F.S. et al. 2023. Biomass and essential oil production of hops cv Chinook in response to nitrogen fertilization. Revista Ceres 70(5):e70509.",
    "publication_year": "2023",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 seasons; N rates 0, 50, 100, 150, 200, 250 kg ha−1",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Authors report the two DM yields and a linear N response; they do not publish a single % gain. Do not stack with other N trials."
  },
  {
    "element_id": "hops-inrow-spacing-agnus-koren-2008",
    "crop_id": "hops",
    "element_type": "plant_density",
    "element_name": "In-row spacing 300 × 114 cm vs standard 300 × 100 cm",
    "claimed_effect": "2.80 t ha−1 dry hops at 300 × 114 cm vs 2.58 t ha−1 at 300 × 100 cm; authors state the calculated per-hectare increase was 10% vs control; 300 × 133 cm yielded 2.69 t ha−1",
    "effect_direction": "increase",
    "baseline_comparison": "common row spacing 300 × 100 cm, four trained bines per hill",
    "study_context": "hybrid cv. Agnus; Hop Research Institute Žatec, Czech Republic; field 2004–2006; 300 cm between rows held constant; five vs four bines also tested",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.17221/2219-PSE",
    "source_citation": "Kořen, J. 2008. Influence of plantation row spacing on quality and yield of hops. Plant, Soil and Environment 54: 276–282.",
    "publication_year": "2008",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Authors: yield increase 'at the limit of significance'; significant in 2005 and 2006, not in average 2004. Alpha acids 12.45% at 300×114 vs 12.29% control."
  },
  {
    "element_id": "mushroom-cultivated-cocopeat-casing-1in-vs-5in",
    "crop_id": "mushroom-cultivated",
    "element_type": "soil_fertility",
    "element_name": "Cocopeat casing 1 inch vs 5 inch thickness",
    "claimed_effect": "638.00 g/bag and 12.76% biological efficiency at 1 in vs 355.00 g/bag at 5 in (cocopeat); vermicompost 1 in 637.00 g/bag vs 5 in 340.00 g/bag",
    "effect_direction": "increase",
    "baseline_comparison": "same casing material at 5 inch thickness (not an uncased control)",
    "study_context": "Agaricus bisporus white button; CRD; cocopeat and vermicompost at 1–5 in",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://www.plantarchives.org/article/275%20EFFECT-OF-DIFFERENT-CASING-THICKNESS-AND-CASING-MATERIAL-ON-YIELD-AND-YIELD-ATTRIBUTING-CHARACTERISTICS-OF-WHITE-BUTTON-MUSHROOM-(A.-BISPORUS).pdf",
    "source_citation": "Effect of different casing thickness and casing material on yield and yield attributing characteristics of white button mushroom (A. bisporus). Plant Archives.",
    "publication_year": "2024",
    "study_design": "greenhouse_trial",
    "sample_size_or_reps": "CRD; five thicknesses × two materials",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Comparison is thickness, not casing vs no casing. 1 in and 2 in were at par. Do not treat 638 g as a % vs industry compost without the 5 in comparator."
  },
  {
    "element_id": "mushroom-cultivated-spawn-rate-2pct-vs-1pct-shibli-2025",
    "crop_id": "mushroom-cultivated",
    "element_type": "plant_density",
    "element_name": "Spawn inoculum 2% vs 1% with supplemented casing",
    "claimed_effect": "highest yields 45.67 and 45.17 kg m−2 at 2% spawn with C3/C2 casings (BE 152.2% and 150.1%) vs 20.79 kg m−2 and 69.3% BE at 1% spawn with C1 casing",
    "effect_direction": "increase",
    "baseline_comparison": "1% inoculum + C1 casing (20.79 kg m−2)",
    "study_context": "Agaricus bisporus; locally produced casing, Al-Wadaq; harvest timing also earlier at 2% (23.3–23.5 d to first fruit vs 30 d)",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.32649/ajas.2025.186645",
    "source_citation": "Shibli, M.I. 2025. The effect of inoculum levels and supplementation of locally produced casing soil on the growth and production of Agaricus bisporus. Anbar Journal of Agricultural Sciences 23(1):311–325.",
    "publication_year": "2025",
    "study_design": "greenhouse_trial",
    "sample_size_or_reps": "factorial spawn × casing",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Spawn rate and casing type are confounded in the extreme contrast (2%+C3 vs 1%+C1). Store the reported cell means; do not reduce to a single %."
  },
  {
    "element_id": "honey-pollen-substitute-diet1-vs-megabee-kim-2024",
    "crop_id": "honey",
    "element_type": "colony_nutrition",
    "element_name": "Pollen substitute Diet 1 (soy/yeast/apple juice/soytide/Chlorella) vs commercial Megabee",
    "claimed_effect": "honey production 14 ± 2 kg/colony (Diet 1) vs 8 ± 1 kg/colony (Megabee control) during Acacia bloom 3–24 May; Diet 1 also highest total adult bees (62,517 ± 424 vs Control 27,925 ± 3854)",
    "effect_direction": "increase",
    "baseline_comparison": "commercial Megabee pollen substitute (not an unfed colony)",
    "study_context": "Apis mellifera; 15 colonies, 3 reps/diet; Gangneung, Republic of Korea; 16 Feb–24 May 2023; diets ~1200 g from 16 Feb–29 Mar then natural forage; honey measured as colony-weight change in Acacia bloom",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/insects15050361",
    "source_citation": "Kim, H., Frunze, O., Lee, J.-H. & Kwon, H.-W. 2024. Enhancing honey bee health: evaluating pollen substitute diets in field and cage experiments. Insects 15(5):361.",
    "publication_year": "2024",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "n=3 colonies per diet",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Authors developed Diet 1; control is Megabee not sugar-only. n=3. Do not convert 14 vs 8 kg into a stacked % with other feeding trials. PLOS ONE Ahmad et al. 2021 (10.1371/journal.pone.0258430) reported similar feeding results but was retracted — not used."
  },
  {
    "element_id": "maple-syrup-vacuum-pump-vs-unpumped-tubing-fs-ne91",
    "crop_id": "maple-syrup",
    "element_type": "harvest_technique",
    "element_name": "Vacuum-pumped tubing vs unpumped tubing on nearly level land",
    "claimed_effect": "authors: vacuum pumping more than doubled sap yield; Area I (up-slope) season total 43.7 vs 16.4 quarts/taphole pumped vs not pumped; Area II 40.2 vs 18.2",
    "effect_direction": "increase",
    "baseline_comparison": "same tubing network without vacuum pump (1968 season)",
    "study_context": "USDA Forest Service; nearly level land; 300-taphole networks; 1968; natural vacuum in unvented tubing previously +43% (Blum 1967) on slopes",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://www.nrs.fs.usda.gov/pubs/rn/rn_ne91.pdf",
    "source_citation": "USDA Forest Service. 1968. Vacuum pumping doubles maple sap yield on flat land. Research Note NE-91.",
    "publication_year": "1968",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "paired 300-taphole areas, one season",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Official USDA note. Store table totals as reported. Later commercial reports of ~20% in VT/NY are a different population — do not average them in."
  },
  {
    "element_id": "maple-syrup-high-yield-retubing-uvm-pmrc-20yr",
    "crop_id": "maple-syrup",
    "element_type": "harvest_technique",
    "element_name": "High-yield vacuum tubing system vs legacy collection (before/after retubing)",
    "claimed_effect": "authors: average syrup 0.58 gal/tap (2004–2023) vs 0.34 gal/tap on the legacy system; 70.6% higher; 90% of post-2004 years exceeded 0.5 gal/tap, none did before",
    "effect_direction": "increase",
    "baseline_comparison": "PMRC legacy sap collection before 2004 retubing (0.34 gal syrup/tap)",
    "study_context": "UVM Proctor Maple Research Center, Vermont; 20 years 2004–2023 after total replacement with modern high-yield vacuum; observational before/after, not a randomized contemporaneous control",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://mapleresearch.org/wp-content/uploads/md20Yr202312.pdf",
    "source_citation": "Perkins, T.D. et al. 2023. Twenty years of high-yield sap collection at the UVM Proctor Maple Research Center. Maple Digest.",
    "publication_year": "2023",
    "study_design": "observational",
    "sample_size_or_reps": "20 production seasons after retubing",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Authors themselves report 70.6%. Weather still caused low years (2012, 2021). Not a randomized trial; Vermont industry also rose 54% over the same period."
  },
  {
    "element_id": "potato-npk-fertiliser-meta-china-li-2025",
    "crop_id": "potato",
    "element_type": "soil_fertility",
    "element_name": "NPK fertiliser vs no fertilisation (China potato meta-analysis)",
    "claimed_effect": "authors: fertilisation increased tuber yield 33.64% vs no fertilisation (180 studies, 1583 observation pairs); single N, P, or K +33.64, +23.37, +16.18%; combined NP, NK, PK +33.64, +36.34, +19.12%; NPK together +49.18%",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control in each primary study",
    "study_context": "Solanum tuberosum; China only; climate, soil nutrients, and planting strategies as covariates; precipitation then cultivar then soil K availability ranked as strongest modifiers",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.17221/514/2025-PSE",
    "source_citation": "Li, S., Zeng, L. & Zhao, L. 2025. Response of potato tuber yield to NPK fertiliser in China: a meta-analysis. Plant, Soil and Environment 71(12):883–890.",
    "publication_year": "2025",
    "study_design": "meta_analysis",
    "sample_size_or_reps": "180 studies; 1583 observation pairs",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Abstract on the journal page. Authors print overall and single-N both as 33.64%; store as written, do not average with non-China potato N trials. Do not copy onto sweet-potato."
  },
  {
    "element_id": "onion-n-rate-82kg-vs-0-yeshiwas-2024",
    "crop_id": "onion",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 82 kg ha−1 (urea, split) vs 0 N",
    "claimed_effect": "marketable bulb yield 26.77 t ha−1 at 82 kg N ha−1 vs 19.09 t ha−1 at 0 N; total bulb yield 26.26 vs 24.97 t ha−1; yield declined above 82 kg (123 kg N ha−1 not higher). Variety × N interaction for yield was not significant.",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control (0 N); TSP 92 kg ha−1 P2O5 on all plots",
    "study_context": "Allium cepa; irrigated RCBD 4 varieties × 4 N rates; Koga, Woreta, Woramit, northwest Ethiopia 2021/22; urea 46% N in two splits",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1371/journal.pone.0312394",
    "source_citation": "Yeshiwas, Y., Alemayehu, M. & Adgo, E. 2024. Enhancing bulb yield through nitrogen fertilization and the use of hybrid onion (Allium cepa L.) varieties in northwest Ethiopia. PLoS ONE 19(10):e0312394.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 locations × 3 replications; N rates 0, 41, 82, 123 kg ha−1",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Full HTML. Do not use the unreviewed 57.84 vs 21.74 t ha−1 figures (not in this paper). Text also states a 38.5% total-yield gain that does not match 26.26 vs 24.97; store the t ha−1 means, not that percentage."
  },
  {
    "element_id": "onion-hybrid-russet-jambar-vs-bombay-red-yeshiwas-2024",
    "crop_id": "onion",
    "element_type": "cultivar_selection",
    "element_name": "Hybrid Russet/Jambar vs open-pollinated Bombay Red",
    "claimed_effect": "marketable bulb yield Russet 26.50 t ha−1 and Jambar 24.57 t ha−1 vs Bombay Red 19.86 t ha−1 (main effect across N rates and three locations); total yield Russet 26.93 and Jambar 25.08 vs Bombay Red 20.45 t ha−1",
    "effect_direction": "increase",
    "baseline_comparison": "open-pollinated Bombay Red (local check)",
    "study_context": "same Yeshiwas et al. 2024 trial; hybrids from commercial supplier, Bombay Red from Melkassa ARC; variety × N interaction for yield ns",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1371/journal.pone.0312394",
    "source_citation": "Yeshiwas, Y., Alemayehu, M. & Adgo, E. 2024. Enhancing bulb yield through nitrogen fertilization and the use of hybrid onion (Allium cepa L.) varieties in northwest Ethiopia. PLoS ONE 19(10):e0312394.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 locations × 3 replications × 4 N rates",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Cultivar main effect, not a cell at 82 kg N. Do not stack onto the N-rate row as a product of two percentages."
  },
  {
    "element_id": "onion-n-rate-150kg-vs-0-bari-piaz4-khan-2024",
    "crop_id": "onion",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 150 kg ha−1 vs 0 N, set-to-bulb BARI Piaz-4",
    "claimed_effect": "bulb yield 22.15 t ha−1 at 150 kg N ha−1 vs 10.05 t ha−1 at 0 N; 180 kg N 21.08 t ha−1 and 120 kg N 20.74 t ha−1 were statistically similar to 150; individual bulb weight 34.22 g vs 17.32 g at 0 N",
    "effect_direction": "increase",
    "baseline_comparison": "0 kg N ha−1",
    "study_context": "BARI Piaz-4; set-to-bulb; Spices Research Sub-Centre Faridpur, Bangladesh; winter 2023–24; RCBD 7 N rates 0–180 kg ha−1",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://objectstorage.ap-dcc-gazipur-1.oraclecloud15.com/n/axvjbnqprylg/b/V2Ministry/o/office-srsc-faridpur/2024/12/0ee6295c2c0e4967a15bb32f9d7b6176.pdf",
    "source_citation": "Khan, M.A., Rahman, M.M. & Sarker, R. 2024. Nitrogen for onion through set to bulb method (BARI Piaz-4). Spices Research Sub-Centre, BARI, Faridpur, 2023–24 annual report.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "7 N rates × 3 replications; one season",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. BARI station report, not a journal. LSD (0.05) for yield 3.402 t ha−1. Do not average with the Ethiopian 82 kg N trial."
  },
  {
    "element_id": "bean-dry-edible-rhizobium-inoculum-meta-sousa-2022",
    "crop_id": "bean-dry-edible",
    "element_type": "biostimulant_inoculant",
    "element_name": "Rhizobium seed inoculum vs uninoculated control",
    "claimed_effect": "authors: Rhizobium inoculation increased seed yield 32.96% vs uninoculated CK; mineral-N fertilizer increased seed yield 46.69% vs CK; RI on average 12.31% less efficient than NF (68 studies, 7 countries)",
    "effect_direction": "increase",
    "baseline_comparison": "uninoculated control (CK); NF is a separate comparator, not the RI baseline",
    "study_context": "Phaseolus vulgaris common/dry bean; peer-reviewed primary studies; response modified by season, tillage, SOM, texture, pH, P availability, and inoculum rate ≥10 g kg−1 seed",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1007/s13593-022-00784-6",
    "source_citation": "dos Santos Sousa, W., Soratto, R.P., Peixoto, D.S. et al. 2022. Effects of Rhizobium inoculum compared with mineral nitrogen fertilizer on nodulation and seed yield of common bean. A meta-analysis. Agronomy for Sustainable Development 42:52.",
    "publication_year": "2022",
    "study_design": "meta_analysis",
    "sample_size_or_reps": "68 studies from 7 countries",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Springer abstract + results snippet with Figure 5a/5b percentages. Common bean, not snap/lima/chickpea. Do not copy onto pea-dry-edible or lentils."
  },
  {
    "element_id": "broccoli-n-rate-120-240-vs-0-vagen-2007",
    "crop_id": "broccoli-including-broccoli-raab",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 120 and 240 kg ha−1 vs 0 N",
    "claimed_effect": "authors: fresh-weight head yield more than doubled at 120 kg N ha−1 and almost tripled at 240 vs 0 N; relative head yield 100, 232, and 295 at 0, 120, and 240 kg N ha−1; companion report of the same Norwegian trials: 6230, 14440, and 18360 kg ha−1 heads at those rates",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control (0 N)",
    "study_context": "Brassica oleracea var. italica cvs Milady and Marathon; southern Norway 1999 and 2001; three silty loams; May vs late-June/July planting; relative yield levelled off at 200–250 kg available N ha−1 (fertiliser + Nmin)",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1080/09064710500539224",
    "source_citation": "Vågen, I.M. 2007. Nitrogen fertilization to broccoli cultivars at different planting times: Yield and nitrogen use. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 57(1):35–44.",
    "publication_year": "2007",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "multiple site-years; 0, 120, 240 kg N ha−1; two cultivars × two planting times",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. T&F abstract/results. Absolute kg ha−1 from the same author's uptake paper on the eight Landvik experiments. Heads, not raab. Do not copy onto cauliflower or cabbage."
  },
  {
    "element_id": "broccoli-n-rate-osu-nwrec-1992",
    "crop_id": "broccoli-including-broccoli-raab",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen rate 180 lb/acre vs 0 N (Willamette silt loam)",
    "claimed_effect": "1992 main-effect total yield 1.6 tons/acre at 0 N vs 3.9 at 60, 5.5 at 120, 6.8 at 180, 6.7 at 240 lb N/acre; four-year NWREC conclusion: optimum near 250 lb N/acre at 30,000–40,000 plants/acre, with earlier years peaking at 250 and declining at 325",
    "effect_direction": "increase",
    "baseline_comparison": "0 lb N/acre",
    "study_context": "OSU North Willamette Research and Extension Center; Willamette silt loam; 1992 rate × timing; prior 1989–90 source trials on the same site",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://agsci.oregonstate.edu/oregon-vegetables/effect-rate-timing-application-and-placement-nitrogen-fertilizer-broccoli-yield-and-nitrogen-uptake",
    "source_citation": "Oregon State University. 1992. Effect of rate, timing of application, and placement of nitrogen fertilizer on broccoli yield and nitrogen uptake. NWREC Oregon Vegetables.",
    "publication_year": "1992",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "N rates 0, 60, 120, 180, 240, 300 lb/acre; one reported year plus four-year synthesis",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Land-grant trial tables. Do not convert tons/acre into a stacked % with the Norwegian trial."
  },
  {
    "element_id": "carrot-n-rate-202-vs-29-metiva-2023",
    "crop_id": "carrot",
    "element_type": "soil_fertility",
    "element_name": "Season-total N 202 kg ha−1 vs starter-only 29 kg ha−1",
    "claimed_effect": "authors: root yield and shoot biomass increased with N and did not plateau; 2019 total yield 78.7 Mg ha−1 at 29 kg N vs 91.3 at 67 and 92.8 at 135; 2020 total 72.0 vs 75.3 vs 77.5 Mg ha−1 at 29/67/135; SARE report of the same trial: 202 kg ha−1 raised yield vs 135 in both years (mean extra 8.1 t ha−1 vs 135 kg N); 2020 no differences among 29, 67, and 135 kg N",
    "effect_direction": "increase",
    "baseline_comparison": "starter-only 29 kg N ha−1 (not a zero-N control)",
    "study_context": "processing carrot; commercial fields near Hesperia and Pentwater, Michigan 2019–2020; rates 29, 67, 135, 202 kg N ha−1; split vs single topdress did not affect yield",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1002/agj2.21257",
    "source_citation": "Metiva, M. et al. 2023. Topdress strategies and remote sensing for nitrogen management in processing carrots. Agronomy Journal 115(1):408–425.",
    "publication_year": "2023",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "2 years on commercial fields; 4 N rates",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Open-access abstract + Table 5 snippet + SARE GNC19-283 write-up of the same trial. Baseline is starter N, not zero. Year × rate: 2020 flat below 202 kg."
  },
  {
    "element_id": "strawberry-silver-black-mulch-full-drip-saridas-2021",
    "crop_id": "strawberry",
    "element_type": "irrigation_practice",
    "element_name": "Silver-on-black polyethylene mulch + full drip (Ir100) vs no mulch + Ir100",
    "claimed_effect": "land productivity 71.9 t ha−1 under silver-on-black + Ir100 vs 59.4 black + Ir100, 52.1 transparent + Ir100, and 51.5 no mulch + Ir100; Ir50 reduced growth/yield parameters except IWUE",
    "effect_direction": "increase",
    "baseline_comparison": "no mulch at the same full-irrigation (Ir100) regime",
    "study_context": "Fragaria × ananassa cv. Fortuna; high tunnel; eastern Mediterranean Turkey 2016–2017; split-plot 4 replicates; drip; mulches silver-on-black, black, transparent, none × Ir100/Ir50",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1016/j.agwat.2020.106568",
    "source_citation": "Sarıdaş, M.A., Kapur, B., Çeliktopuz, E., Şahiner, Y. & Kargı, S.P. 2021. Land productivity, irrigation water use efficiency and fruit quality under various plastic mulch colors and irrigation regimes of strawberry in the eastern Mediterranean region of Turkey. Agricultural Water Management 245:106568.",
    "publication_year": "2021",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "split-plot, 4 replicates, one season",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Abstract numbers. Mulch is under irrigation_practice per taxonomy (moisture retention). Skipped an unverified 28.4 vs 12.3 t ha−1 agriculturaljournals.com PDF. High-tunnel Fortuna; do not copy onto raspberry."
  },
  {
    "element_id": "apple-insect-pollination-vs-exclusion-olhnuud-2022",
    "crop_id": "apple",
    "element_type": "pollination_management",
    "element_name": "Open insect pollination vs pollinator exclusion (and vs hand pollination)",
    "claimed_effect": "authors: fruit set 71% higher and seed set 62% higher with open insect access vs exclusion; fruit set 41% lower and seed set 20% lower with open pollination than with artificial/hand pollination (pollination deficit). Deficit largest in Asia (fruit set 63%) then Europe (30%). 48 studies, five continents.",
    "effect_direction": "increase",
    "baseline_comparison": "pollinator exclusion for the contribution contrast; hand/artificial pollination for the deficit contrast",
    "study_context": "Malus domestica; global meta-analysis of fruit set and seed set; 45 cultivars / 17 countries in the WUR summary; cultivar effects confounded with continent",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1111/1365-2664.14279",
    "source_citation": "Olhnuud, A., Liu, Y., Makowski, D., Tscharntke, T., Westphal, C., Wu, P., Wang, M. & van der Werf, W. 2022. Pollination deficits and contributions of pollinators in apple production: a global meta-analysis. Journal of Applied Ecology 59(12):2911–2921.",
    "publication_year": "2022",
    "study_design": "meta_analysis",
    "sample_size_or_reps": "48 studies across five continents",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Fruit set/seed set, not harvested t ha−1. Two different comparators — do not add 71% and 41%. Do not copy onto pear or peach."
  },
  {
    "element_id": "almond-honeybee-independence-saez-2020",
    "crop_id": "almond",
    "element_type": "pollination_management",
    "element_name": "Honey bee access vs whole-tree mesh isolation on self-fertile Independence",
    "claimed_effect": "authors: final fruit set ~60% higher with bees (0.30 and 0.33 fruits/flower open and mesh-control vs 0.19 isolated); kernel yield ~20% higher (5.53 ± 0.39 kg/tree open and 5.31 ± 0.33 mesh-control vs 4.49 ± 0.18 isolated). Oleic:linoleic ratio unchanged.",
    "effect_direction": "increase",
    "baseline_comparison": "whole trees bagged from bees (isolation); mesh-control trees had a roof mesh that still allowed visits",
    "study_context": "Prunus dulcis cv. Independence; Kings County, California 2018; 30 young trees; 10 per treatment; 5 colonies/ha; orchard 50/50 Nonpareil–Independence",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1038/s41598-020-59995-0",
    "source_citation": "Sáez, A., Aizen, M.A., Medici, S., Viel, M., Villalobos, E. & Negri, P. 2020. Bees increase crop yield in an alleged pollinator-independent almond variety. Scientific Reports 10:3177.",
    "publication_year": "2020",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "10 trees per treatment (isolation, open, mesh-control)",
    "conflict_of_interest_flag": true,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. PMC7035345 full text. Funded by Beeflow Inc. (pollination company; coauthor Viel affiliated). Authors declare no competing interests; flag remains true. Young trees, one county, one season. Do not apply to Nonpareil or to walnut/pistachio."
  },
  {
    "element_id": "blueberry-insect-pollination-r2-eeraerts-2023",
    "crop_id": "blueberry",
    "element_type": "pollination_management",
    "element_name": "Insect-mediated pollination vs bagged flowers (and hand vs open for pollen limitation)",
    "claimed_effect": "authors: insect-mediated pollination increased fruit set, berry weight and seed set (R² 64.8%, 75.9%, 75.2%); additional hand pollination vs open raised those metrics (R² 10.1%, 18.2%, 21.5%). Honeybee and wild-bee visitation also associated with fruit set (R² 5.4% and 3.5%). 21 studies, 496 site replicates.",
    "effect_direction": "increase",
    "baseline_comparison": "bagged/exclusion for the insect-service contrast; open pollination for the hand-pollination (pollen-limitation) contrast",
    "study_context": "highbush blueberry (Vaccinium corymbosum); mostly North America; few cultivars; honey bees dominant, wild bees more efficient per visit",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1111/1365-2664.14516",
    "source_citation": "Eeraerts, M. et al. 2023. Synthesis of highbush blueberry pollination research reveals region-specific differences in the contributions of honeybees and wild bees. Journal of Applied Ecology 60:2528–2539.",
    "publication_year": "2023",
    "study_design": "meta_analysis",
    "sample_size_or_reps": "21 studies; 496 site replicates",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. The 64.8/75.9/75.2 figures are R², not percent yield gains. A USDA-ARS interpretive summary restated them as 'increased by 64.8%' — that conversion is not stored. Do not copy onto cranberry or raspberry."
  },
  {
    "element_id": "asparagus-subsurface-drip-n-fertigation-rolbiecki-2022",
    "crop_id": "asparagus",
    "element_type": "irrigation_practice",
    "element_name": "Subsurface drip N fertigation vs broadcast N without irrigation",
    "claimed_effect": "authors: six-year mean marketable green-spear yield 8.79 t ha−1 with subsurface drip fertigation vs 5.69 t ha−1 on non-irrigated plots with spreading N; increase 3.1 t ha−1, i.e. 54%",
    "effect_direction": "increase",
    "baseline_comparison": "spreading nitrogen fertilisation without irrigation (not a zero-N control)",
    "study_context": "Asparagus officinalis cvs Ramada, Rapsody, Ravel; sandy soil, central Poland 2011–2017 harvests 2012–2017; split-plot 4 replications; fertigation confounds water and N placement",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/agronomy12020241",
    "source_citation": "Rolbiecki, R., Sadan, H., Rolbiecki, S., Jagosz, B., Szczepanek, M., Figas, A., Atilgan, A., Pal-Fam, F. & Pańka, D. 2022. Effect of subsurface drip fertigation with nitrogen on the yield of asparagus grown for the green spears on a light soil in central Poland. Agronomy 12(2):241.",
    "publication_year": "2022",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "6 harvest years; 3 cultivars; 4 replications",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Results paragraph on the journal page. Water and N placement are confounded; do not treat 54% as a pure N-rate effect. Green spears, not white. Do not copy onto asparagus-fern."
  },
  {
    "element_id": "cabbage-n-180-240-s-kacjan-marsic-2021",
    "crop_id": "cabbage-including-chinese",
    "element_type": "soil_fertility",
    "element_name": "Calcium ammonium nitrate 180 or 240 kg N ha−1 ± 40 kg S ha−1 vs 0 N",
    "claimed_effect": "marketable yield 30.3 ± 1.6 t ha−1 at 0 N vs 62.7 ± 1.8 at 180 N without S, 67.4 ± 2.3 at 180 N + 40 S, 66.8 ± 2.4 at 240 N without S, and 75.8 ± 2.6 at 240 N + 40 S (Table 1). Authors: 180 N + 40 S more than doubled the unfertilised yield.",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control (0 N, 0 S)",
    "study_context": "white cabbage Brassica oleracea var. capitata; Central Slovenia, humid temperate; CAN and gypsum; N × S interaction on head weight and yield",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/plants10071304",
    "source_citation": "Kacjan Maršić, N., Sinkovič Može, K., Mihelič, R., Nečemer, M., Hudina, M. & Jakopič, J. 2021. Nitrogen and sulphur fertilisation for marketable yields of cabbage (Brassica oleracea L. var. Capitata), leaf nitrate and glucosinolates and nitrogen losses studied in a field experiment in Central Slovenia. Plants 10(7):1304.",
    "publication_year": "2021",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 N × 2 S treatments; Table 1 means ± SE",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Table 1 on the journal page. White headed cabbage, not Chinese cabbage — crop_id is the USDA compound. Do not copy onto broccoli or cauliflower."
  },
  {
    "element_id": "sweet-potato-n-application-meta-china-ji-2024",
    "crop_id": "sweet-potato",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen fertiliser vs no N (China sweetpotato meta-analysis)",
    "claimed_effect": "authors: N application increased fresh tuber yield 1.7% and single-tuber weight 3.2%, and reduced tubers per plant 1.2% (45 papers, 288 yield groups). Peak yield increment at N <75 kg ha−1; higher N generally smaller increments. With K2O 150–225 kg ha−1, yield increment 10.5%.",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised or zero-N controls in primary studies",
    "study_context": "Ipomoea batatas; China; northern vs Yangtze vs southern regions; fresh vs starch types; control yield level modifies response",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.11674/zwyf.2024056",
    "source_citation": "Ji, H., Zhao, H., Zeng, Y., Cheng, R., Wang, S., Wang, Y. & Zhao, H. 2024. Meta-analysis on the effect and influence factors of nitrogen application on tuber yield of sweet potato in China. Journal of Plant Nutrition and Fertilizers 30(8):1606–1620.",
    "publication_year": "2024",
    "study_design": "meta_analysis",
    "sample_size_or_reps": "45 papers; 288 yield groups",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. English abstract on the journal page. Store the small overall +1.7%; do not replace it with the 10.5% K-interaction subset. Do not copy onto potato."
  },
  {
    "element_id": "eggplant-n-rate-100kg-vs-0-aminifard-2010",
    "crop_id": "eggplant",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 100 kg ha−1 vs 0 N",
    "claimed_effect": "yield per plant 3713 g at 100 kg N ha−1 vs 2615 g at 0 N; fruit weight 375.0 g vs 301.7 g control; 150 kg N 3591 g/plant and 298.3 g fruit (below the 100 kg peak)",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control (0 N)",
    "study_context": "Solanum melongena field trial; N rates 0, 50, 100, 150 kg ha−1; vegetative growth highest at 150 kg, fruit yield peaked at 100 kg",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.5513/JCEA01/11.4.863",
    "source_citation": "Aminifard, M.H., Aroiee, H., Fatemi, H., Ameri, A. & Karimpour, S. 2010. Responses of eggplant (Solanum melongena L.) to different rates of nitrogen under field conditions. Journal of Central European Agriculture 11(4):453–458.",
    "publication_year": "2010",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "4 N rates; table of treatment means",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Table 4 in the PDF. Per-plant grams, not t ha−1. 150 kg N did not beat 100 kg. Do not copy onto tomato or pepper."
  },
  {
    "element_id": "garlic-n-50lb-vs-0-cornell-cce-2018",
    "crop_id": "garlic",
    "element_type": "soil_fertility",
    "element_name": "Spring-applied inorganic N 50 lb/acre vs 0 N (and vs 100/150 lb)",
    "claimed_effect": "authors: in 8 side-by-side comparisons, never a yield response among 50, 100 and 150 lb N/acre; in year 2, 50 lb/acre increased yield 20% vs 0 lb/acre. Residual soil nitrate at harvest 6, 22, 38, 76 lb/acre at 0/50/100/150.",
    "effect_direction": "mixed",
    "baseline_comparison": "0 lb/acre spring N for the 20% contrast; 50 lb/acre for the null among higher rates",
    "study_context": "German hardneck garlic; Cornell Vegetable Program; 2017–2018; three sites, three configurations, three N sources/methods",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://cvp.cce.cornell.edu/submission.php?id=763",
    "source_citation": "Cornell Cooperative Extension Vegetable Program. 2018. Nitrogen requirements in garlic: 50 lb/A is enough!",
    "publication_year": "2018",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "8 paired comparisons; 2 years; 3 sites",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Land-grant on-farm write-up. Store the null among 50–150 as well as the 20% vs zero. Do not average with tropical NPS garlic trials."
  },
  {
    "element_id": "grape-deficit-irrigation-60pct-cwr-elsalhy-2026",
    "crop_id": "grape-including-raisin",
    "element_type": "irrigation_practice",
    "element_name": "Deficit irrigation 60% of crop water requirement vs 100% CWR",
    "claimed_effect": "authors: yield/vine decreased 17.11% at 60% CWR and 3.70% at 80% CWR vs 100% CWR; 80% vs 100% not statistically different. Table 7: 2024 yield 10.50, 10.14, 8.66 kg/vine and 2025 11.12, 10.67, 9.25 kg/vine at 100/80/60% CWR.",
    "effect_direction": "decrease",
    "baseline_comparison": "full irrigation (100% CWR)",
    "study_context": "Vitis vinifera cv. Flame seedless; 19-year vines; Luxor, Egypt 2024–2025; sandy soil; drip; 80% CWR also raised TSS/anthocyanin vs 100%",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1038/s41598-026-47407-8",
    "source_citation": "El-Salhy, A.M., Salem, E.H., Mohamed, M.M.A. & Hussein, A.S. 2026. Deficit-irrigation management for sustainable grape production (Vitis vinifera L.): different regimes to assess yield and berry quality under arid conditions. Scientific Reports 16:12724.",
    "publication_year": "2026",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 treatments × 3 replications × 4 vines; 2 seasons",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. PMC13090379 full text. 80% CWR is a non-significant 3.70% dip; the stored direction is the significant 60% cut. Table grape, not wine. Do not copy onto grapevines (nursery)."
  },
  {
    "element_id": "cherry-insect-vs-exclusion-vs-hand-osterman-2023",
    "crop_id": "cherry",
    "element_type": "pollination_management",
    "element_name": "Open insect pollination vs bagged exclusion (and vs hand pollination) on cv. Regina",
    "claimed_effect": "final fruit set bagged 0–6% (mean 2%) vs open insect 9–69% (mean 28%) vs hand 7–68% (mean 39%); treatments differed at harvest (Tukey p<0.001). Fruit set rose with honey bee × mason bee abundance together, not with either species alone.",
    "effect_direction": "increase",
    "baseline_comparison": "fine-mesh insect exclusion for the contribution contrast; hand pollination for the deficit contrast",
    "study_context": "Prunus avium cv. Regina (self-sterile S1S3); 17 orchards, Sachsen-Anhalt and Thuringia, Germany, 2020; 20 trees/site",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1002/ece3.10289",
    "source_citation": "Osterman, J. et al. 2023. Mason bees and honey bees synergistically enhance fruit set in sweet cherry orchards. Ecology and Evolution 13:e10289.",
    "publication_year": "2023",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "17 orchards; 20 Regina trees per orchard; 3 pollination treatments",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. PMC10329911 full text. Fruit set, not kg/tree. Sweet cherry cv. Regina; do not copy onto sour cherry without the Osterman 2024 review (pollen limitation detected for sweet, not sour)."
  },
  {
    "element_id": "raspberry-pollinator-exclusion-marketable-set-ryan-2023",
    "crop_id": "raspberry",
    "element_type": "pollination_management",
    "element_name": "Insect pollination vs pollinator exclusion (marketable fruit set)",
    "claimed_effect": "authors: average reduction in marketable fruit set of 68.2% when pollinators excluded (Diamond Jubilee 70.4%, Sapphire 66.4%; D = 0.68) across two cultivars and three years. Hand supplementation of open flowers did not raise marketable set above insect-pollinated branches.",
    "effect_direction": "increase",
    "baseline_comparison": "pollinator-exclusion bags",
    "study_context": "Rubus idaeus commercial farm near Reading, England 2019–2021; cvs Diamond Jubilee and Sapphire; fruit set, marketable fruit set, fruit weight",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1002/ece3.10044",
    "source_citation": "Ryan, I.C., Shutt, J.D. & Dicks, L.V. 2023. The importance of multi-year studies and commercial yield metrics in measuring pollinator dependence ratios: a case study in UK raspberries Rubus idaeus L. Ecology and Evolution 13(5):e10044.",
    "publication_year": "2023",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "3 years; 2 cultivars; branch-level exclusion/open/hand",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. D = 0.68 is the authors' pollinator-dependence ratio (proportion of yield lost without pollinators), not an R². Do not copy onto blackberry or blueberry."
  },
  {
    "element_id": "cauliflower-n-rate-0-vs-225-bozkurt-2011",
    "crop_id": "cauliflower",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 225 kg ha−1 vs 0 N (drip, Mediterranean coastal Turkey)",
    "claimed_effect": "Table VI main-effect curd yield 8.81 Mg ha−1 at 0 N vs 29.1 at 75, 31.0 at 150, and 33.9 at 225 kg N ha−1; predicted maximum 33.9 Mg ha−1 at 225 kg N. Irrigation main effect: 13.4 Mg ha−1 at Kcp0 vs 32.0 at Kcp1.0.",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised N0 (irrigation held as a crossed factor)",
    "study_context": "Brassica oleracea var. botrytis; Eastern Mediterranean coastal Turkey 2005–2007; four N rates × four pan coefficients; Duncan means",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1080/09064710.2010.539575",
    "source_citation": "Bozkurt, S., Uygur, V., Agca, N. & Yalcin, M. 2011. Yield responses of cauliflower (Brassica oleracea L. var. Botrytis) to different water and nitrogen levels in a Mediterranean coastal area. Acta Agriculturae Scandinavica, Section B — Soil & Plant Science 61(2):183–194.",
    "publication_year": "2011",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years; 4 N × 4 irrigation levels",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Table VI in the T&F PDF. Do not copy onto broccoli or cabbage."
  },
  {
    "element_id": "spinach-n-rate-0-to-300-null-canali-2014",
    "crop_id": "spinach",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 0, 150, 225, 300 kg ha−1 on overwinter processing spinach",
    "claimed_effect": "authors: fresh and dry yield among fertilizing treatments were similar; processing spinach yielded 37.8 t ha−1 fresh and 3.6 t ha−1 dry (two-experiment mean). N dose strongly influenced leaf NO3− (1286 mg kg−1 mean) but not β-carotene or lutein. Authors recommend 225 kg N ha−1 as a maximum for the Foggia plain trade-off, not as a yield peak vs zero.",
    "effect_direction": "no_significant_effect",
    "baseline_comparison": "0 kg N ha−1 in Experiment 1",
    "study_context": "Spinacia oleracea processing crop; Southern Italy, two-year field trial; Experiment 1 N doses 0/150/225/300 kg ha−1",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1016/j.eja.2013.11.013",
    "source_citation": "Canali, S. et al. 2014. Alternative strategies for nitrogen fertilization of overwinter processing spinach (Spinacia oleracea L.) in Southern Italy. European Journal of Agronomy 54:47–55.",
    "publication_year": "2014",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 years; 4 N doses in Experiment 1",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Honest null on yield. Do not backfill a % from other spinach papers. Not Tetragonia (New Zealand spinach)."
  },
  {
    "element_id": "melon-watermelon-n-270-vs-0-gulut-2021",
    "crop_id": "melon-all-types",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 270 kg ha−1 vs 0 N on grafted watermelon (urea, split)",
    "claimed_effect": "2018 yield 32581 kg ha−1 at 0 N + 0 B vs 55454 at 270 N + 0 B and 56505 at 270 N + 2 kg B; 2019 29581 vs 43925 (0 B) and 52513 (2 kg B). Authors: highest yield, fruit weight and sugars at 270 kg N ha−1.",
    "effect_direction": "increase",
    "baseline_comparison": "0 kg N ha−1 (N1) at the same B dose",
    "study_context": "grafted watermelon cv. Starburst; Çukurova, Turkey 2018–2019; N 0/90/180/270 kg ha−1 × B 0/2 kg ha−1; urea in three splits",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1371/journal.pone.0252396",
    "source_citation": "Gülüt, K.Y. 2021. Nitrogen and boron nutrition in grafted watermelon I: Impact on pomological attributes, yield and fruit quality. PLoS ONE 16(5):e0252396.",
    "publication_year": "2021",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 years; 4 N × 2 B; 4 replications",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. PMC8162669 Table 3. Watermelon is under melon-all-types. Do not copy onto pumpkin or squash."
  },
  {
    "element_id": "ginseng-n1-20gm2-vs-n0-li-2025",
    "crop_id": "ginseng",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 20 g m−2 vs 0 and vs 40 g m−2",
    "claimed_effect": "authors: yield peaked at N1 816.56 g m−2; 29.90% above N0 and 38.05% above N2 (p<0.05). Unimodal: both zero and 40 g m−2 lowered biomass vs the intermediate rate.",
    "effect_direction": "mixed",
    "baseline_comparison": "N0 (0 g N m−2) for the +29.90% contrast; N2 (40 g m−2) is a high-N decrease",
    "study_context": "Panax ginseng two-year seedlings; Baishan, Jilin; plots 5 m2 × 3 reps; N0/N1/N2 = 0/20/40 g m−2 plus P and K on N plots; harvest 2022",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1186/s12870-025-07031-6",
    "source_citation": "Li, K., Wan, M., Han, M. & Yang, L. 2025. The response of Panax ginseng root microbial communities and metabolites to nitrogen addition. BMC Plant Biology 25:969.",
    "publication_year": "2025",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 N rates × 3 replicates",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. PMC12302684 full text. High N (N2) reduced yield vs N1 — store the decrease. Panax ginseng, not notoginseng."
  },
  {
    "element_id": "stevia-n-urea-100-vs-0-poland-2024",
    "crop_id": "stevia",
    "element_type": "soil_fertility",
    "element_name": "Urea or ammonium nitrate 100–150 kg N ha−1 vs 0 N",
    "claimed_effect": "Table 3: plant yield 13770 ± 2010 kg ha−1 (control) vs 24370 ± 4900 (urea 100) and 24330 ± 2510 (ammonium nitrate 150); leaf yield 7630 ± 400 vs 14900 ± 2860 (urea 100) and 14830 ± 1630 (AN 150). Authors: 100 or 150 kg N as urea or AN increased yield.",
    "effect_direction": "increase",
    "baseline_comparison": "unfertilised control C",
    "study_context": "Stevia rebaudiana; three consecutive field years in Poland; urea, ammonium nitrate, ammonium sulphate at 50/100/150 kg N ha−1",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/molecules29081865",
    "source_citation": "Śniegowska, J., Biesiada, A. & Gasiński, A. 2024. Influence of the nitrogen fertilization on the yield, biometric characteristics and chemical composition of Stevia rebaudiana Bertoni grown in Poland. Molecules 29(8):1865.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years; 3 N sources × 3 rates + control",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. PMC11054086 Table 3. Poland stevioside was low; yield not glycoside. Do not copy onto sugar beet."
  },
  {
    "element_id": "coneflower-n-150-vs-0-dry-herb-soltanbeigi-2022",
    "crop_id": "coneflower",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 150 kg ha−1 vs 0 N (five cuttings, 3 years)",
    "claimed_effect": "across five cuttings: dry herb 3817 ± 3277 kg ha−1 at 0 N vs 8746 ± 6947 at 150 kg N and 7745 ± 6069 at 75 kg N + foliar; fresh herb 14109 vs 32645 vs 29291 kg ha−1; essential oil 1.54 vs 4.55 vs 3.57 L ha−1. Authors: 150 kg N and 75 kg N + foliar highest agronomic yield.",
    "effect_direction": "increase",
    "baseline_comparison": "F0 control / 0 N",
    "study_context": "Echinacea purpurea; Afyonkarahisar, Turkey 2016–2018; F0/F1 75/F2 150/F3 75+foliar",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.29393/chjaa38-16ayah20016",
    "source_citation": "Soltanbeigi, A. & Maral, H. 2022. Agronomic yield and essential oil properties of purple coneflower (Echinacea purpurea L. Moench) with different nutrient applications. Chilean Journal of Agricultural & Animal Sciences 38.",
    "publication_year": "2022",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years; 4 fertilizer treatments; five cuttings pooled",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Treatment means from the trial PDF (high SDs; direction consistent). Purple coneflower = USDA coneflower. DOI 10.29393/chjaa38-16ayah20016; KMÜ repository PDF used to read Table means."
  },
  {
    "element_id": "st-john-s-wort-n250-p100-vs-0-azizi-2002",
    "crop_id": "st-john-s-wort",
    "element_type": "soil_fertility",
    "element_name": "250 kg N + 100 kg P ha−1 vs unfertilised control",
    "claimed_effect": "authors: highest herb yield 1053.9 g m−2 at 250 kg N + 100 kg P vs 745.8 g m−2 in the control. NP-supply also increased flowering stems and hypericin; all fertiliser treatments raised herb Cd vs control (highest Cd 0.269 mg kg−1 at 250 N + 200 P vs 0.091 in control).",
    "effect_direction": "increase",
    "baseline_comparison": "control plot (0 N, 0 P)",
    "study_context": "Hypericum perforatum cv. Topas; Tarbiat Modarres University near Tehran; two seasons 1998–1999; N 0/150/250 × P 0/100/200 kg ha−1",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.17660/ActaHortic.2002.576.39",
    "source_citation": "Azizi, M. & Omidbaigi, R. 2002. Effect of NP supply on herb yield, hypericin content and cadmium accumulation of St. John's wort (Hypericum perforatum L.). Acta Horticulturae 576:267–271.",
    "publication_year": "2002",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 seasons; 3 N × 3 P",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Abstract numbers on ISHS/DOI page. Peak is an N×P combination, not N alone. Cd increase is stored; do not drop the negative quality result."
  },
  {
    "element_id": "fenugreek-n-90-vs-0-jagdale-2011",
    "crop_id": "medicinal-herbs-fenugreek",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 90 kg ha−1 vs 0 N (seed yield)",
    "claimed_effect": "Table 1/2: seed yield 11.67 q ha−1 at 0 N vs 12.85 at 30, 14.44 at 60, 15.29 at 90, and 13.90 at 120 kg N ha−1. Peak at 90 kg N (15.29 q ha−1; 307.16 g/plot); 120 kg N below the 90 kg peak.",
    "effect_direction": "mixed",
    "baseline_comparison": "N0 (0 kg N ha−1); P levels crossed",
    "study_context": "Trigonella foenum-graecum; Dr. PDKV Akola, Maharashtra; factorial RBD 5 N × 5 P, 3 replications",
    "source_tier": "B",
    "source_type": "peer_reviewed",
    "source_url": "http://researchjournal.co.in/upload/assignments/6_81-84_2.pdf",
    "source_citation": "Jagdale, Y.L. & Dalve, P.D. 2011. Effect of nitrogen and phosphorus levels on seed yield and quality of fenugreek. Asian Journal of Horticulture 6(1):81–84.",
    "publication_year": "2011",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "25 treatments; 3 replications",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Hind Asian J. Hort. PDF tables. Stored on medicinal-herbs-fenugreek (dual USDA listing with culinary fenugreek). q = quintal. Do not merge with culinary-herb price series."
  },
  {
    "element_id": "lavender-n-100-vs-0-kucukyumuk-2015",
    "crop_id": "medicinal-herbs-lavender",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 100 kg ha−1 vs 0 N on lavandin Super A",
    "claimed_effect": "authors' table: dry flower 217.9 kg ha−1 at 0 N vs 2998 at 50, 3849 at 100, and 3277 at 150 kg N (2010); 2011 230.9 / 3054 / 3905 / 3367. Fresh flower 540.4 vs 8991 kg ha−1 at 0 vs 100 kg N in 2010. Peak at 100 kg N; 150 kg N below that peak both years.",
    "effect_direction": "mixed",
    "baseline_comparison": "0 kg N ha−1",
    "study_context": "Lavandula × intermedia var. Super A; randomized block, 3 replications; two years 2010–2011",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1080/0972060X.2014.960279",
    "source_citation": "Kucukyumuk, Z. et al. 2015. Effect of different nitrogen doses on plant growth, quality characteristics and nutrient concentrations of lavandin (Lavandula × intermedia Emeric ex Loisel. var. Super A). Journal of Essential Oil Bearing Plants 18(1):36–43.",
    "publication_year": "2015",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 years; 4 N rates; 3 replications",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. TEOP table as published. 0 N vs 100 kg N is an extreme jump (authors' numbers, not converted). Lavandin Super A stored on medicinal-herbs-lavender (dual listing with culinary lavender). Unimodal: 150 kg N below 100 kg N."
  },
  {
    "element_id": "artichoke-n-rate-200lb-highest-numerical-schrader-1992",
    "crop_id": "artichoke",
    "element_type": "soil_fertility",
    "element_name": "Drip N 100 vs 200 vs 400 lb/ac (weekly ammonium nitrate)",
    "claimed_effect": "authors: 200 lb/ac gave the highest numerical yield both years (Table 2). Raw kg/ha cells were not in the accessible article text.",
    "effect_direction": "increase",
    "baseline_comparison": "100 and 400 lb N/ac in the same drip trial",
    "study_context": "seed-propagated globe artichoke; Irvine CA 1989–1990; N applied weekly through drip",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://doi.org/10.3733/ca.v046n04p28",
    "source_citation": "Schrader, W.L., Mayberry, K.S. & Cudney, D.W. 1992. Paving the way to a better artichoke. California Agriculture 46(4):28–29.",
    "publication_year": "1992",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 years; 3 N rates",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Section 0: Table 2 numeric cells not in the accessible PDF text; stored the authors' 'highest numerical yield' statement only. Do not invent kg/ha."
  },
  {
    "element_id": "artichoke-irrigation-50etc-vs-100-shinohara-2011",
    "crop_id": "artichoke",
    "element_type": "irrigation_practice",
    "element_name": "Subsurface drip 50% vs 100% ETc (N rates crossed)",
    "claimed_effect": "authors: marketable yields significantly increased at 100% ETc vs 75% and 50% ETc; a 20% to 35% yield reduction occurred at 50% ETc across seasons. Lack of yield response to N rates attributed to high pre-plant soil N.",
    "effect_direction": "decrease",
    "baseline_comparison": "100% ETc",
    "study_context": "globe artichoke; Uvalde, TX 2005–2008; 50/75/100% ETc × N 0–10/60/120/180 kg ha−1; subsurface drip",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.21273/HORTSCI.46.3.377",
    "source_citation": "Shinohara, T., Agehara, S., Yoo, K.S. & Leskovar, D.I. 2011. Irrigation and nitrogen management of artichoke: yield, head quality, and phenolic content. HortScience 46(3):377–386.",
    "publication_year": "2011",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 seasons",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. 20–35% is the authors' stated range. N-rate null stored in claimed_effect; do not invent a Texas N %."
  },
  {
    "element_id": "okra-n-150-vs-0-manipur-2024",
    "crop_id": "okra",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 150 kg ha−1 vs 0 N (cv. Arka Anamika)",
    "claimed_effect": "N main effect fruit yield 11.42 t ha−1 at 0 N vs 15.60 at 125, 17.14 at 150, and 16.53 t ha−1 at 175 kg N. Peak at 150 kg N (11.11 kg/plot). Closer spacing S3 19.32 t ha−1 (spacing main effect).",
    "effect_direction": "mixed",
    "baseline_comparison": "N0 = 0 kg ha−1; spacing crossed",
    "study_context": "Abelmoschus esculentus cv. Arka Anamika; CAU Imphal, Manipur Apr–Aug 2021; FRBD 3 spacings × 4 N; US-data gap",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://journals.stmjournals.com/rrjob/article=2024/view=156950/",
    "source_citation": "Influence of plant density and nitrogen application on yield and economic viability of okra (cv. Arka Anamika) in Manipur. Research & Reviews: Journal of Botany 2024.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "FRBD; 3 spacings × 4 N",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US. Table means from the journal/PDF. 175 kg N below the 150 kg peak. No US land-grant quantified N trial located this pass."
  },
  {
    "element_id": "beet-table-osu-fg13-extension-guidance",
    "crop_id": "beet-table",
    "element_type": "soil_fertility",
    "element_name": "OSU table-beet fertilizer guide (Mack/Gardner/Jackson experiments)",
    "claimed_effect": "",
    "effect_direction": "mixed",
    "baseline_comparison": "not a trial contrast — extension guide",
    "study_context": "Oregon table beet; FG 13 grounded in OSU field experiments but no single quantified yield table in the guide",
    "source_tier": "C",
    "source_type": "extension_guidance",
    "source_url": "https://ir.library.oregonstate.edu/downloads/c247ds851",
    "source_citation": "Oregon State University Extension. Table beets fertilizer guide FG 13 (Mack, H.J., Gardner, E.H. & Jackson, T.L.).",
    "publication_year": "",
    "study_design": "none",
    "sample_size_or_reps": "",
    "conflict_of_interest_flag": false,
    "confidence": "low",
    "reviewer_notes": "pass=context_only. Do not backfill a %. Do not attach sugar-beet yield numbers to beet-table. identity_flags=same_species_different_crop vs sugar-beet (Beta vulgaris)."
  },
  {
    "element_id": "sugar-beet-aonr-unl-mitchell-agj2-21617",
    "crop_id": "sugar-beet",
    "element_type": "soil_fertility",
    "element_name": "Agronomic optimum N for irrigated sugar beet (root vs sugar yield)",
    "claimed_effect": "authors: agronomic optimum N 166 kg ha−1 for sugar yield vs 179 kg ha−1 for root yield (UNL Panhandle REEC, Mitchell NE, 2020–2022).",
    "effect_direction": "increase",
    "baseline_comparison": "N-rate response curve (not a zero-N pairwise %)",
    "study_context": "irrigated sugar beet; Mitchell, NE 2020–2022",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1002/agj2.21617",
    "source_citation": "Optimizing nitrogen management to enhance irrigated sugar beet yield and quality. Agronomy Journal. DOI 10.1002/agj2.21617.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. identity_flags=same_species_different_crop vs beet-table. Do not copy AONR onto table beet."
  },
  {
    "element_id": "pumpkin-illinois-2018-variety-johanning",
    "crop_id": "pumpkin",
    "element_type": "cultivar_selection",
    "element_name": "2018 Illinois pumpkin cultivar trial",
    "claimed_effect": "replicated Midwestern land-grant cultivar comparison (University of Illinois Extension; Purdue Midwest Vegetable Trial Reports).",
    "effect_direction": "mixed",
    "baseline_comparison": "other cultivars in the same trial",
    "study_context": "Illinois 2018 pumpkin variety trial; part of Midwest compilation",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://docs.lib.purdue.edu/fvtrials/169/",
    "source_citation": "Johanning, N.R. 2018. 2018 pumpkin variety trial. Midwest Vegetable Trial Reports. Purdue e-Pubs.",
    "publication_year": "2018",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "replicated cultivar trial",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Extension trial (discovery-spec Tier B). Do not merge with squash or melon."
  },
  {
    "element_id": "squash-zucchini-ncsu-2020-cultivar",
    "crop_id": "squash-summer-and-winter",
    "element_type": "cultivar_selection",
    "element_name": "2020 NC State zucchini cultivar evaluations",
    "claimed_effect": "RCB, four replications, Central Crops Research Station Clayton NC; graded marketable yield (fancy/#2/cull) by cultivar.",
    "effect_direction": "mixed",
    "baseline_comparison": "other zucchini cultivars in the same trial",
    "study_context": "Cucurbita pepo zucchini; Clayton NC 2020",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://cucurbits.ces.ncsu.edu/growing-cucurbits/variety-trials/2020-zucchini-squash-cultivar-evaluations/",
    "source_citation": "NC State Cucurbits. 2020 zucchini squash cultivar evaluations.",
    "publication_year": "2020",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "RCB; 4 replications",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Summer squash/zucchini under squash-summer-and-winter. Do not copy onto pumpkin."
  },
  {
    "element_id": "squash-summer-msu-2022-phillips",
    "crop_id": "squash-summer-and-winter",
    "element_type": "cultivar_selection",
    "element_name": "2022 MSU summer squash cultivar trial",
    "claimed_effect": "completely randomized design, four replications, SW Michigan REC; final plant population 3,630 plants/acre; yields by cultivar and size class.",
    "effect_direction": "mixed",
    "baseline_comparison": "other summer squash cultivars in the same trial",
    "study_context": "SW Michigan REC, Benton Harbor 2022",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://docs.lib.purdue.edu/mwvtr/236",
    "source_citation": "Phillips, B. & Schoonmaker, J. 2022. 2022 summer squash cultivar trial. Midwest Vegetable Trial Reports.",
    "publication_year": "2022",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "4 replications; 3630 plants/acre",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Separate row from the NC State zucchini trial."
  },
  {
    "element_id": "sweet-corn-n-timing-site-year-paranhos-2025",
    "crop_id": "sweet-corn",
    "element_type": "soil_fertility",
    "element_name": "N rate 224–336 kg ha−1 × emergence/sidedress timing, GA/AL",
    "claimed_effect": "authors: yield not significantly affected by N treatment; location main effect Alabama 2022 17,380 kg ha−1 vs Georgia 2020 15,951 and Alabama 2021 14,470. Highest site-year used moderate N (224–280 kg ha−1).",
    "effect_direction": "no_significant_effect",
    "baseline_comparison": "N-rate/timing treatments within site-year; site-years not averaged",
    "study_context": "Zea mays var. rugosa; Vidalia GA 2020 and E.V. Smith AL 2021–2022; loamy sand",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/nitrogen6020020",
    "source_citation": "Paranhos, J. et al. 2025. Impacts of nitrogen fertilizer application timing and rate on sweet corn production under subtropical environmental conditions. Nitrogen 6(2):20.",
    "publication_year": "2025",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 site-years",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Keep site-years separate; do not average 17380 across GA/AL. Honest N-rate null."
  },
  {
    "element_id": "melon-watermelon-uga-tifton-2019-cultivar",
    "crop_id": "melon-all-types",
    "element_type": "cultivar_selection",
    "element_name": "2019 UGA Tifton watermelon variety trial",
    "claimed_effect": "total yield 52,959–99,924 lb/acre (2019, Tifton); Exclamation highest-yielding, not significantly different from 11 others (Fisher's Protected LSD P<0.05).",
    "effect_direction": "mixed",
    "baseline_comparison": "other watermelon cultivars in the same trial",
    "study_context": "Tifton, GA 2019; University of Georgia vegetable trials",
    "source_tier": "B",
    "source_type": "extension_trial",
    "source_url": "https://vegetables.caes.uga.edu",
    "source_citation": "University of Georgia. Watermelon variety trial evaluation 2019. Tifton.",
    "publication_year": "2019",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "replicated; LSD P<0.05",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Watermelon under melon-all-types. Do not copy onto pumpkin/squash. Range is across cultivars, not a fertilizer contrast."
  },
  {
    "element_id": "fig-cultivar-lsu-italian376-aklo-gordon-acta1310",
    "crop_id": "fig",
    "element_type": "cultivar_selection",
    "element_name": "USDA-ARS/UC Chowchilla fig cultivar trial",
    "claimed_effect": "authors: LSU Purple, Italian 376, and Aklo Lalo (AL) had the highest yields; despite high yield LSU is not a commercially viable cultivar for California fig production due to small fruit size, whereas AL and Italian 376 have large and moderately sized fruit.",
    "effect_direction": "mixed",
    "baseline_comparison": "other cultivars in the 12-cultivar replicated planting",
    "study_context": "12 cultivars from USDA-ARS NCGR Davis planted at Chowchilla CA; fresh fruit year 3",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.17660/ActaHortic.2021.1310.26",
    "source_citation": "Gordon, P., Preece, J.E., Ferguson, L. et al. Field evaluation of new and underutilized fig cultivars for fresh and dried markets. Acta Horticulturae 1310:26.",
    "publication_year": "2021",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "12 cultivars; replicated; year-3 fruit",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Do not store 'LSU = highest yield' without the commercial-viability caveat."
  },
  {
    "element_id": "blackberry-n-10-vs-others-reynoso-2011",
    "crop_id": "blackberry",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 10 or 10-split kg ha−1 vs 0 and 20 kg ha−1 (high tunnel)",
    "claimed_effect": "thesis abstract: total fruit yields for Treatments 2 and 3 (10 and 10-split kg ha−1) 2.5 kg each, highest and significantly different from the other treatments (p<0.05). Marketable yield similar trend, ns. Cane diameter and plant fresh weight ns.",
    "effect_direction": "increase",
    "baseline_comparison": "0 kg ha−1 control and 20 kg ha−1 (the 'other treatments')",
    "study_context": "Prime-Ark 45 primocane blackberry; University of Arkansas Fayetteville 2011; high tunnel; RCB",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://scholarworks.uark.edu/etd/2259/",
    "source_citation": "Reynoso Campos, J.C. 2014. Primocane-fruiting blackberry: optimum N-fertilization. University of Arkansas thesis.",
    "publication_year": "2014",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "RCB; 4 N treatments",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. High tunnel. Control and 20 kg ha−1 pairwise kg not in the abstract; do not invent them. ASHS 2012 poster used different rate labels — thesis 0/10/10-split/20 is the source of record."
  },
  {
    "element_id": "blackberry-primejan-primejim-ar-vs-or-clark-2005",
    "crop_id": "blackberry",
    "element_type": "cultivar_selection",
    "element_name": "Prime-Jan / Prime-Jim primocane yield, Arkansas vs Oregon",
    "claimed_effect": "total primocane yield Prime-Jan 412–3,048 kg ha−1 (Clarksville AR) vs 4,103–17,179 kg ha−1 (Oregon); Prime-Jim 220–1,835 vs 1,661–20,010 kg ha−1. Strong location × cultivar effect. Oregon column is single-plot without statistics per authors' footnote.",
    "effect_direction": "mixed",
    "baseline_comparison": "the other cultivar at the same location; locations not averaged",
    "study_context": "University of Arkansas Fruit Substation Clarksville (est. 1999) and OSU N. Willamette REC Aurora (est. 2000)",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.21273/HORTSCI.40.3.852",
    "source_citation": "Clark, J.R., Moore, J.N., Lopez-Medina, J., Perkins-Veazie, P. & Finn, C.E. 2005. 'Prime-Jan' (APF-8) and 'Prime-Jim' (APF-12) primocane-fruiting blackberries. HortScience 40(3):852–855.",
    "publication_year": "2005",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "two locations; Oregon column un-replicated per footnote",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Do not average AR and OR. Do not copy onto raspberry."
  },
  {
    "element_id": "pistachio-foliar-null-lovatt-beede-frep-09-0584",
    "crop_id": "pistachio",
    "element_type": "soil_fertility",
    "element_name": "Foliar N/B/Zn/K strategies vs untreated control",
    "claimed_effect": "authors: no foliar fertilizer treatment significantly increased total dry weight of split nuts per tree in either year; no effect on 2-year cumulative yield. Year 1 mean 19.8 kg split nuts/tree vs Year 2 7.9 (P<0.0001) from alternate bearing, not fertilizer. Control Year 1 19.6 kg/tree.",
    "effect_direction": "no_significant_effect",
    "baseline_comparison": "untreated control",
    "study_context": "15-yr-old Kerman on Pioneer Gold 1; Paramount Farming orchard, Kings County CA; RCB 11–12 treatments × 15 single-tree reps; 2 years",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://www.cdfa.ca.gov/is/ffldrs/frep/pdfs/completedprojects/09-0584Lovatt.pdf",
    "source_citation": "Lovatt, C.J. & Beede, R.H. Towards development of foliar fertilization strategies for pistachio… CDFA FREP Agreement 09-0584.",
    "publication_year": "2013",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "15 single-tree replications × 11–12 treatments; 2 years",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Section 0 COI: funding CDFA FREP + UCR AES (public). Paramount Farming supplied the orchard and harvest data — cooperator, not sponsor. Honest null kept."
  },
  {
    "element_id": "avocado-rootstock-duke7-vs-g755b-screc",
    "crop_id": "avocado",
    "element_type": "cultivar_selection",
    "element_name": "Hass on 10 clonal rootstocks, Phytophthora-free",
    "claimed_effect": "cumulative yields years 2–5 highest on Duke 7 (103.5 kg/tree), lowest on G755B (19.5 kg/tree); no statistical difference in average fruit size years 2–4.",
    "effect_direction": "increase",
    "baseline_comparison": "G755B (lowest) and the other eight rootstocks",
    "study_context": "UC South Coast REC; Hass on ten rootstocks in the absence of Phytophthora cinnamomi",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://www.avocadosource.com/WAC",
    "source_citation": "Avocado clonal rootstock production trial. UC South Coast REC / Avocado Source WAC.",
    "publication_year": "",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "10 rootstocks; cumulative years 2–5",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Phytophthora cinnamomi absent — may not generalize to infected sites. avocadosource is an access point; UC SCREC is the institution."
  },
  {
    "element_id": "walnut-sdi-33-50-75-vs-100-chandler",
    "crop_id": "walnut",
    "element_type": "irrigation_practice",
    "element_name": "Sustained deficit irrigation 33/50/75% vs 100% control",
    "claimed_effect": "cv. Chandler 6.7 / 6.4 / 12.2 kg/tree under SDI33/50/75 vs 13.9 kg/tree at C100; cv. Cisco 8.0 / 11.6 / 11 / 15.6 kg/tree. Three years.",
    "effect_direction": "decrease",
    "baseline_comparison": "full irrigation C100",
    "study_context": "mountainous water-starved environments; Chandler and Cisco; 3 years",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12197118/",
    "source_citation": "Yield and quality of walnuts subjected to deficit irrigation in mountainous water-starved environments. PMC12197118.",
    "publication_year": "2025",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years; 2 cultivars",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US corroboration of deficit irrigation. Do not copy onto pecan or pistachio."
  },
  {
    "element_id": "apricot-thinning-0-vs-40-trevett",
    "crop_id": "apricot",
    "element_type": "pruning_training",
    "element_name": "Hand thinning 0–40% of fruit (cv. Trevett)",
    "claimed_effect": "thinning decreased fruit drop from 21% to 0.51% and increased fruit weight from 15.93 g to 26.61 g, but yield per branch decreased from 0.794 kg (0% control) to 0.408 kg (40% thinning).",
    "effect_direction": "decrease",
    "baseline_comparison": "0% thinning control",
    "study_context": "Prunus armeniaca cv. Trevett; Khyber Pakhtunkhwa Agricultural University 2007–08; RCBD 4 reps; 8 thinning levels",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "http://pakbs.org/pjbot/PDFs/44(3)/07.pdf",
    "source_citation": "Rab, A., Rahman, J., Abdiani, S., Qadim, A., Khattak, M.K. & Nawab, K. 2012. Thinning intensity affects the yield and fruit quality of apricot cv. Trevett. Pakistan Journal of Botany 44(3):887–890.",
    "publication_year": "2012",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "RCBD; 4 replications; 8 treatments",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US. Yield/branch fell while fruit weight rose. Do not copy onto peach/nectarine."
  },
  {
    "element_id": "kiwi-cppu-preanthesis-cruz-castillo-2014",
    "crop_id": "kiwi",
    "element_type": "biostimulant_inoculant",
    "element_name": "Pre-anthesis CPPU 4 μL L−1 vs untreated",
    "claimed_effect": "authors: CPPU significantly increased fresh weight by about 12% (+12.6 g fruit−1) and consequently the yield per vine, without affecting firmness, dry matter, TSS, sugars, vitamin C, or oxalic acid.",
    "effect_direction": "increase",
    "baseline_comparison": "untreated control",
    "study_context": "Actinidia deliciosa cv. Hayward; Central Italy 2008; spray at break of sepals ~1 week before anthesis",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1016/j.foodchem.2014.01.131",
    "source_citation": "Cruz-Castillo, J.G., Baldicchi, A., Frioni, T., Marocchi, F., Moscatello, S., Proietti, S., Battistelli, A. & Famiani, F. 2014. Pre-anthesis CPPU low dosage application increases 'Hayward' kiwifruit weight… Food Chemistry 158:224–228.",
    "publication_year": "2014",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "field trial 2008",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US. regulatory_flag=true: forchlorfenuron/CPPU is restricted in some jurisdictions — R&D caveat, not a grower recommendation. Abstract also reports +11.6% / +12.59 g in Results; stored the abstract's 'about 12% (+12.6 g)'."
  },
  {
    "element_id": "macadamia-high-n-depressed-yield-stephenson-2000",
    "crop_id": "macadamia",
    "element_type": "soil_fertility",
    "element_name": "Nitrogen 1150 vs 230 g/tree/year",
    "claimed_effect": "authors: higher N increased kernel recovery by ~1% in 5 of 6 years; these increases were insufficient to compensate for depressed yields (17% lower) at high nitrogen. Commercial-sized NIS 33.8 / 29.6 / 28.8 kg/tree at low/medium/high N (P<0.05). Authors indicate 355 g N/tree.year.",
    "effect_direction": "decrease",
    "baseline_comparison": "low rate 230 g N/tree/year",
    "study_context": "SE Queensland DPI/CSIRO; 6-year replicated field trial; N 230/690/1150 g/tree/year across split timings",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1071/EA99077",
    "source_citation": "Stephenson, R.A., Gallagher, E.C., Doogan, V.J. & Mayer, D.G. 2000. Nitrogen and environmental factors influencing macadamia quality. Australian Journal of Experimental Agriculture 40(8):1145–1150.",
    "publication_year": "2000",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "6 years; 3 N rates × split timings",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US. US-data gap: no open-access Hawaii replicated rate table located. 17% is the authors' stated depression at high N."
  },
  {
    "element_id": "macadamia-uh-ctaHR-res039-extension-guidance",
    "crop_id": "macadamia",
    "element_type": "soil_fertility",
    "element_name": "UH-CTAHR Macadamia Nuts in Hawaii (Res-039) cultivation bulletin",
    "claimed_effect": "",
    "effect_direction": "mixed",
    "baseline_comparison": "not a trial contrast — extension bulletin",
    "study_context": "Hawaii; 1984 cultivation bulletin, not a replicated rate-yield table",
    "source_tier": "C",
    "source_type": "extension_guidance",
    "source_url": "https://www.ctahr.hawaii.edu/oc/freepubs/pdf/Res-039.pdf",
    "source_citation": "University of Hawaii CTAHR. Macadamia Nuts in Hawaii. Research Extension Series 039 (1984).",
    "publication_year": "1984",
    "study_design": "none",
    "sample_size_or_reps": "",
    "conflict_of_interest_flag": false,
    "confidence": "low",
    "reviewer_notes": "pass=context_only. Do not backfill a % from the Australian trial onto this Hawaii bulletin."
  },
  {
    "element_id": "pineapple-density-low-vs-high-djido-2021",
    "crop_id": "pineapple",
    "element_type": "plant_density",
    "element_name": "Planting density 54,400 vs 74,000 plants ha−1 (cv. Sugarloaf)",
    "claimed_effect": "authors: The yield increased from 54.9–69.1 up to 90.1 t.ha−1 with an increase in the planting density. The increase in the yield from low planting density to high planting density varied between 25 and 33%. Yield increase was not at the expense of fruit weight (density ns on fruit weight).",
    "effect_direction": "increase",
    "baseline_comparison": "low density 54,400 plants ha−1 (farmers' practice)",
    "study_context": "Ananas comosus cv. Sugarloaf; four on-farm experiments, Atlantic Department, Benin; split-plot density × K2O:N",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3389/fpls.2021.627808",
    "source_citation": "Djido, U., Fassinou Hotegni, N.V., Lommen, W.J.M., Hounhouigan, J.D., Achigan-Dako, E.G. & Struik, P.C. 2021. Effect of planting density and K2O:N ratio on the yield… of pineapple fruits in Benin. Frontiers in Plant Science 12:627808.",
    "publication_year": "2021",
    "study_design": "on_farm_trial",
    "sample_size_or_reps": "4 experiments; 4 blocks; 9 treatments",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Section 0: 25–33% is the authors' own stated range (Results, Table 6), not computed here from 54.9–69.1 to 90.1. geographic_scope=non_US."
  },
  {
    "element_id": "pineapple-uh-ctaHR-fn7-extension-guidance",
    "crop_id": "pineapple",
    "element_type": "soil_fertility",
    "element_name": "UH-CTAHR Pineapple Cultivation in Hawaii (F&N-7)",
    "claimed_effect": "",
    "effect_direction": "mixed",
    "baseline_comparison": "not a trial contrast — cultivation guide",
    "study_context": "Hawaii; 2002 cultivation guide, not a replicated yield table",
    "source_tier": "C",
    "source_type": "extension_guidance",
    "source_url": "https://www.ctahr.hawaii.edu/oc/freepubs/pdf/F_N-7.pdf",
    "source_citation": "University of Hawaii CTAHR. Pineapple Cultivation in Hawaii. Fruits and Nuts F&N-7 (2002).",
    "publication_year": "2002",
    "study_design": "none",
    "sample_size_or_reps": "",
    "conflict_of_interest_flag": false,
    "confidence": "low",
    "reviewer_notes": "pass=context_only. Do not backfill Benin density % onto this Hawaii guide."
  },
  {
    "element_id": "papaya-uh-ctaHR-fn3-extension-guidance",
    "crop_id": "papaya",
    "element_type": "soil_fertility",
    "element_name": "UH-CTAHR Papaya Production in Hawaii (F&N-3)",
    "claimed_effect": "",
    "effect_direction": "mixed",
    "baseline_comparison": "not a trial contrast — cultivation guide",
    "study_context": "Hawaii; fertilizer recommendations without a replicated rate-yield table",
    "source_tier": "C",
    "source_type": "extension_guidance",
    "source_url": "https://www.ctahr.hawaii.edu/oc/freepubs/pdf/F_N-3.pdf",
    "source_citation": "University of Hawaii CTAHR. Papaya Production in Hawaii. Fruits and Nuts F&N-3.",
    "publication_year": "",
    "study_design": "none",
    "sample_size_or_reps": "",
    "conflict_of_interest_flag": false,
    "confidence": "low",
    "reviewer_notes": "pass=context_only. US-data gap for a replicated papaya N-rate table."
  },
  {
    "element_id": "citrus-np-rate-null-kadyampakeni-ifas-2024",
    "crop_id": "citrus",
    "element_type": "soil_fertility",
    "element_name": "Variable N and P rates on HLB-affected Florida citrus",
    "claimed_effect": "authors: no yield differences regardless of treatment effect and nutrient application rates (fruit quality still underway). Valencia orange N-rate and P-rate slides: increases in year 2 but no differences between treatments.",
    "effect_direction": "no_significant_effect",
    "baseline_comparison": "N and P rate treatments including low/zero-P in the statewide BMP trials",
    "study_context": "UF/IFAS CREC / statewide N and BMP trials; HLB-affected sweet orange; USDA Hatch-linked nutrient management program",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://citrusagents.ifas.ufl.edu/media/crecifasufledu/citrus-agents/growers-institutes/2024/Kadyampakeni_bmp-.pdf",
    "source_citation": "Kadyampakeni, D. 2024. An update on citrus N and BMP statewide trials. UF/IFAS Citrus Institute, Avon Park.",
    "publication_year": "2024",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "multi-site statewide trials",
    "conflict_of_interest_flag": false,
    "confidence": "medium",
    "reviewer_notes": "pass=paper_read. Honest null kept (spec Section 4). Trade-press coverage of related CRF work involves Harrell's/Tiger Sul cooperators; this row cites the UF/IFAS primary. Do not attach to citrus-trees floriculture crop_id."
  },
  {
    "element_id": "citrus-obreza-morgan-sl253-extension-guidance",
    "crop_id": "citrus",
    "element_type": "soil_fertility",
    "element_name": "Nutrition of Florida Citrus Trees (SL253)",
    "claimed_effect": "",
    "effect_direction": "mixed",
    "baseline_comparison": "not a trial contrast — fertilizer bulletin",
    "study_context": "Florida citrus; UF/IFAS SL253/SS478 recommendations",
    "source_tier": "C",
    "source_type": "extension_guidance",
    "source_url": "https://edis.ifas.ufl.edu/publication/ss478",
    "source_citation": "Morgan, K.T. & Kadyampakeni, D.M. Nutrition of Florida Citrus Trees, 3rd ed. UF/IFAS SL253/SS478.",
    "publication_year": "2020",
    "study_design": "none",
    "sample_size_or_reps": "",
    "conflict_of_interest_flag": false,
    "confidence": "low",
    "reviewer_notes": "pass=context_only. Do not backfill a % from the BMP null trial into this bulletin."
  },
  {
    "element_id": "date-strand-thinning-30pct-vs-control-khadrawi",
    "crop_id": "date",
    "element_type": "pruning_training",
    "element_name": "Strand thinning 15% and 30% vs no thinning (cv. Khadrawi)",
    "claimed_effect": "authors: removing 30% of strands gave the lowest bunch weight and yield/palm vs control (no thinning) but improved fruit weight, length, and diameter and raised TSS/sugars.",
    "effect_direction": "decrease",
    "baseline_comparison": "control (no thinning)",
    "study_context": "Phoenix dactylifera cv. Khadrawi; RCBD 3 replicates, 1 palm/replicate; 2015–2016",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1186/s42269-019-0234-3",
    "source_citation": "Strand thinning of Khadrawi date palm cultivar in relation to yield and fruit quality. Bulletin of the National Research Centre. DOI 10.1186/s42269-019-0234-3.",
    "publication_year": "2019",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "RCBD; 3 replicates; 2 years",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. geographic_scope=non_US. Yield/palm fell; fruit quality rose. US-data gap for Coachella replicated thinning tables."
  },
  {
    "element_id": "peach-thinning-bloom-vs-unthinned-horticulturae-2020",
    "crop_id": "peach",
    "element_type": "pruning_training",
    "element_name": "Bloom or 21 DAFB thinning vs unthinned trees",
    "claimed_effect": "authors: thinning at bloom or 21 DAFB improved fruit size vs unthinned trees, but bloom-thinning reduced fruit yield (kg/tree) in one year (flower thinning alone may not be viable in that region).",
    "effect_direction": "mixed",
    "baseline_comparison": "unthinned trees",
    "study_context": "commercial mature Georgia orchards; three years; multiple cultivars",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.3390/horticulturae6030041",
    "source_citation": "Optimizing fruit-thinning strategies in peach (Prunus persica) production. Horticulturae 6(3):41.",
    "publication_year": "2020",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "3 years; multiple cultivars",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. Size up, yield down in one year — store both. Do not copy onto nectarine."
  },
  {
    "element_id": "olive-compost-reduced-n-curtright-2025",
    "crop_id": "olive",
    "element_type": "soil_fertility",
    "element_name": "Compost + 25–50% less synthetic N in SHD orchards",
    "claimed_effect": "authors: trees maintained the same yields and oil quality with 25–50% less nitrogen than traditional-orchard recommendations.",
    "effect_direction": "no_significant_effect",
    "baseline_comparison": "traditional-orchard N recommendations (same yield at reduced N)",
    "study_context": "super-high-density commercial orchards near Woodland and Stockton CA; 2-year replicated field experiment; grower cooperators",
    "source_tier": "A",
    "source_type": "peer_reviewed",
    "source_url": "https://doi.org/10.1007/s13593-025-01050-1",
    "source_citation": "Curtright, A.J. et al. 2025. Compost application and reduced synthetic nitrogen fertilization promote sustainable olive production in super-high-density orchards. Agronomy for Sustainable Development 45.",
    "publication_year": "2025",
    "study_design": "replicated_field_trial",
    "sample_size_or_reps": "2 years; 2 CA sites",
    "conflict_of_interest_flag": false,
    "confidence": "high",
    "reviewer_notes": "pass=paper_read. 25–50% is the authors' N-reduction range at equal yield, not a yield %. Grower cooperators, public/academic authorship."
  }
]