Foliar application of potassium and iron enhances biomass and essential oil production of basil cultivated in aquaponics and hydroponics

Metadata

Cite key: roostaFoliarApplicationPotassium2025
Item type: Journal Article
Authors: H.R. Roosta, S.M.A. Rezaei, M. Raghami
Affiliation: Department of Horticultural Sciences, Faculty of Agriculture and Environment, Arak University, Arak, Iran (Roosta); Department of Horticultural Sciences, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran (Rezaei, Raghami)
Journal: Scientific Reports 16 (2025), Article 3828
Date: Received 11 March 2025; Accepted 23 December 2025 (see Extraction notes on a page-header year discrepancy)
Date added: 2026-08-10
DOI: 10.1038/s41598-025-33937-0
Funding: “The authors received no specific funding for this work.”
URL: https://doi.org/10.1038/s41598-025-33937-0
PDF: Roosta et al. - 2025 - Foliar application of potassium and iron enhances biomass and essential oil production of basil cult.pdf

Opinion

This paper IS a genuine aquaponics study, not the hydroponic-only paper it might sound like from the title alone — common carp are stocked in real recirculating tanks, and the design directly compares coupled aquaponics (water sourced straight from the fish tank), decoupled aquaponics (fish water enriched with fertilizer to match a hydroponic target), and pure hydroponics (Hoagland solution), crossed with a foliar potassium/iron spray. Water-quality reporting (Table 1) is genuinely good — means +/- SD for 17 parameters across all three/four solution variants, internally consistent with the paper’s own arithmetic (harvest mass x stocking density reproduces the stated mean fish weight exactly). The problem is everything else: almost the entire plant-side results section (growth, biomass, leaf area, SPAD, chlorophylls, carotenoids, anthocyanin, seven leaf minerals, essential oil content — 13-14 distinct measured variables across 18 treatment cells) is reported ONLY as bar charts with Duncan letters. Not one table, and only a handful of pooled percentage-difference figures in the text (e.g., “+39.81%” for plant height, Aquaponics vs Hoagland). Per this vault’s never-read-a-figure rule, essentially every plant.csv row and most trials.csv growth cells in this note are NR, despite the paper clearly having collected and statistically analyzed all of it. There is also a garden-variety internal quirk worth flagging: the stated essential-oil-yield formula is written backwards (dry-sample-mass divided by oil mass, rather than the reverse), and one feed-protein sentence reads like generic citation-supported background rather than a lab-specific value. Neither affects any extracted cell. Net: solid, well-instrumented water-chemistry data and a real fish-vs-decoupled-vs-hydroponic aquaponics comparison, but almost no usable quantitative plant data as written up — useful primarily for its water-quality panel and its qualitative foliar-supplementation narrative.

Abstract

Aquaponics offers sustainable cultivation by integrating aquaculture and hydroponics, yet nutrient limitations often constrain plant performance. This study evaluated the effects of three nutrient solutions (aquaponics, Hoagland, and Hoagland + aquaponics) combined with foliar applications of iron and potassium (1000 mg/L) on morphological, physiological, and biochemical characteristics of green and purple basil (Ocimum basilicum L.) cultivars in a completely randomized factorial design with three replications. Results demonstrated that aquaponics nutrient solution significantly enhanced plant height (39.81%), internode length (43.32%), stem diameter (30.88%), shoot (40.41%) and root (105.43%) biomass, leaf number (51.92%) and leaf area (51.95%) compared to Hoagland-treated plants. Foliar potassium and iron applications substantially improved growth parameters across both cultivars, with green basil showing superior performance overall. Photosynthetic pigments (chlorophyll a, b) were highest in green basil under aquaponics with potassium spray, while purple basil accumulated more anthocyanins compared to green basil. Mineral analysis revealed that K concentration was lower in aquaponics, although foliar K treatments effectively increased K concentrations in leaves, in all nutrient solutions. Essential oil content was notably higher in aquaponics-grown plants and further enhanced by potassium and iron foliar applications, particularly in green basil. Strong positive correlations were observed between growth parameters, and essential oil production. These findings demonstrate that combining aquaponics with strategic foliar supplementation of potassium and iron represents an effective approach for optimizing basil production, quality, and essential oil yield in sustainable cultivation systems.

Summary

The authors grew green (Italian large leaf) and purple basil in pots (70% cocopeat / 30% perlite) at Vali-e-Asr University, Iran, over fall/winter 2021-2022, in a factorial design crossing three nutrient sources — coupled aquaponics (water taken directly from a common-carp RAS, no fertilizer added), decoupled “Hoagland + Aquaponics” (fish water enriched with fertilizer to match the hydroponic target), and plain Hoagland hydroponic solution — with a foliar spray treatment (distilled-water control, 1000 mg/L potassium sulfate, or 1000 mg/L ferrous sulfate, twice weekly from the 8-leaf stage), replicated 3 times (pots) per of the 18 resulting cells. They measured a large panel of growth parameters (height, internode length, stem diameter, branch/node/leaf number, leaf area, shoot/root fresh and dry mass, root volume), pigments (chlorophyll a/b/total, carotenoids, anthocyanin, SPAD), leaf minerals (K, Ca, Na, Fe, Mn, Zn, Cu), and essential oil content, alongside a real fish-production dataset for the carp themselves (FCR 1.53, 100% survival, mean harvest mass 568.6 g). Aquaponics nutrient solution outperformed Hoagland alone on essentially every pooled growth metric (e.g., +39.81% plant height, +105.43% root biomass), and foliar potassium and iron sprays further improved growth, pigments, and essential oil content in most treatment combinations, with green basil generally more responsive than purple. Leaf potassium was consistently lower under aquaponics alone than under Hoagland or the fertilizer-enriched decoupled treatment, but foliar K spray raised leaf K in all three nutrient solutions. Essential oil content was higher under aquaponics and further increased by both K and Fe sprays, especially in green basil, and strong positive correlations linked overall plant vigor to essential oil yield. Critically for downstream data use, almost all of these results (everything except the pooled percentage-difference headline figures and Table 1’s water-chemistry panel) are reported only as bar charts with statistical letters, with no accompanying data table and no absolute numbers in the running text.

Experiment data

Location: Hydroponic greenhouse of Vali-e-Asr University, Rafsanjan, Iran; fall/winter 2021-2022

Design: Factorial completely randomized design, 2 basil cultivars (green, purple) x 3 nutrient solutions (Aquaponics, Hoagland, Hoagland+Aquaponics) x 3 foliar sprays (control/K/Fe, 1000 mg/L) = 18 treatment cells, 3 pot-replications/cell, 9 plants/pot (27 plants/cell for growth analysis; n=3 for biochemical analysis)

Replicates / n: 3 pots per treatment cell (stated “three replications”)

Duration: 75 days from foliar-spray initiation (8-leaf stage) to harvest; fish “cultured for 6 months” (imprecise, see Extraction notes)

Organisms: Ocimum basilicum (green/Italian large leaf and purple cultivars) / Common carp (Cyprinus carpio)

Statistics: Factorial ANOVA (SAS) + Duncan’s multiple range test (p<0.05); means +/- SE; graphs in Excel

Water quality (Table 1, trial means +/- SD): Aquaponics NO3-N 37.2 (influent) / 34.8 (effluent) mg/L vs Hoagland 187.05 and HA 198.04 mg/L — confirms the paper’s core “aquaponics nutrient-limited” premise; NO2-N in both HA (1.64) and Aquaponics (1.72 influent) exceeds the paper’s own stated fish tolerance limit of <0.2 mg/L, acknowledged in text

Fish production: FCR 1.53, survival 100%, mean harvest mass 568.6 g (28,430 g/m3 / 50 fish/m3 — internally consistent)

Growth (pooled, Aquaponics vs Hoagland, no absolute values given): +39.81% plant height, +43.32% internode length, +30.88% stem diameter, +40.41% shoot biomass, +105.43% root biomass, +51.92% leaf number, +51.95% leaf area

Everything else (SPAD, chlorophylls, carotenoids, anthocyanin, 7 leaf minerals, essential oil, all 18-cell-level growth data): figure-only (bar charts with Duncan letters), no numeric values in text or tables

Nutrient-solution comparison (coupled vs decoupled vs hydroponic)

This paper: Aquaponics nutrient solution (coupled, no fertilizer added) significantly outperformed Hoagland alone on every pooled growth metric reported as a percentage (plant height +39.81%, internode length +43.32%, stem diameter +30.88%, shoot biomass +40.41%, root biomass +105.43%, leaf number +51.92%, leaf area +51.95%; Abstract and Results 3.2, identical wording in both places, p.5). This is the opposite direction from several other aquaponics-vs-hydroponics basil/herb comparisons in the literature (see Compared with below), and the authors attribute it to “optimized nutrient balance from both organic and mineral sources” (p.12) without further mechanistic detail. Leaf potassium was the one nutrient consistently lower under aquaponics alone than under Hoagland or the fertilizer-enriched Hoagland+Aquaponics (HA) treatment (Results 3.4/Discussion, no absolute values given), which the paper frames as the specific deficiency foliar K spray was designed to correct. Table 1’s own water chemistry supports this asymmetric picture: aquaponic water NO3-N (37.2 mg/L influent) is roughly 5x lower than Hoagland’s (187.05 mg/L), yet growth was still higher under aquaponics — a genuine tension the paper does not resolve or discuss (it simply reports both findings separately, in different sections).

Compared with:

todo Roosta and Hamidpour 2011 — this vault’s companion paper (Roosta and Hamidpour - 2011 - Effects of foliar application of some macro- and m...pdf, being extracted separately), same corresponding author, tomato instead of basil; cited here (ref 12) for foliar K/Fe increasing vegetative growth under aquaponics but having no effect under hydroponics — growth direction (aquaponics needing the foliar boost more) matches, but that paper reportedly found hydroponic tomato growth characteristics higher than aquaponic overall (p.13), the opposite ranking from this paper’s basil result
todo Roosta 2014 — basil, different hydroponic:aquaponic irrigation ratios; cited (ref 39) as finding fresh root mass higher under “Hoagland nutrient conditions with aquaponic solution” (i.e. a blended/decoupled-like treatment) than Hoagland alone — consistent direction with this paper’s HA-vs-H comparison, though this paper gives no absolute HA-vs-H growth numbers to compare against (p.14)
todo Mangeli 2016 — tomato, foliar calcium nitrate, hydroponic vs aquaponic; cited (ref 40) for lower leaf Ca under aquaponics than hydroponics, matching this paper’s Ca finding (p.19)
todo Roosta and Ghorbani 2011 — mint and peppermint, hydroponics vs aquaponics; cited (ref 52) for most growth factors being higher under hydroponics than aquaponics in mint (fresh/dry shoot and root mass), the opposite ranking from this paper’s basil finding (p.4, p.14)
todo Rotaru, Manuel and Sirbu 2019 — lettuce, pilot-scale aquaponic vs hydroponic; cited (ref 17) for higher productivity in aquaponic than hydroponic units, matching this paper’s direction (p.4)

Foliar potassium and iron supplementation

This paper: Foliar K and Fe sprays (1000 mg/L, twice weekly from the 8-leaf stage) both improved growth, pigment content, mineral status and essential oil content relative to the distilled-water control, across all three nutrient solutions and both cultivars, though the specific best-performing combination differed by trait (e.g., G-A-K — green basil, Aquaponics, K spray — gave the highest shoot fresh/dry mass; G-A-Fe gave the highest total chlorophyll and chlorophyll a; Results 3.2-3.3, Figs 3, 6). Foliar K measurably raised leaf K concentration in all three nutrient solutions, including aquaponics, which the authors present as direct evidence of successful foliar uptake correcting a root-zone K limitation (Results 3.4, Discussion p.16-17). Essential oil content was higher under aquaponics than either Hoagland-containing solution, and was further increased by both K and Fe foliar sprays in all three nutrient solutions, most consistently in green basil (Results, Fig 13). None of these comparisons have an absolute numeric value anywhere in text or tables — see Extraction notes.

Compared with:

todo Kumar and Kumar 2008 — banana cv. Robusta, foliar potassium sulfate; cited (ref 44) for increased relative chlorophyll content via a role in chlorophyll-precursor synthesis and antioxidant protection, offered as the mechanistic basis for this paper’s K-spray chlorophyll effect (p.16)
todo Pal and Ghosh 2010 — African marigold, potassium sulfate/chloride; cited (ref 45) for increased leaf chlorophyll and nitrate uptake with K application, consistent direction (p.16)
todo Zavar 2014 — lemon, nano iron chelate foliar spray; cited (ref 48) for increased leaf chlorophyll under hydroponic conditions via foliar Fe, consistent with this paper’s own Fe-spray chlorophyll result (p.17-18)
todo Roosta and Mohsenian 2012 — pepper, foliar spray of different Fe sources under aquaponics; cited (ref 46) for increased leaf chlorophyll content, matching direction here (p.17)
todo Roosta, Estaji and Niknam 2018 — lettuce, Fe/Zn/Mn shortage; cited (ref 47) for iron deficiency reducing chlorophyll content and disrupting the electron transport chain, offered as the mechanistic rationale for this paper’s Fe-spray effect (p.17-18)
todo Moghadam et al. 2015 — holy basil, foliar iron chelate; cited (ref 60) for increased essential oil yield with foliar Fe, matching this paper’s essential-oil finding (p.19-20)
todo Said-Al Ahl, Ayad and Hendawy 2009 — oregano, potassium humate; cited (ref 58) for increased essential oil yield with K application, consistent direction (p.19)
todo Pavela et al. 2018 — thyme, foliar N/P/K; cited (ref 59) for increased essential oil content and composition with nutrient-element foliar application, consistent direction (p.19-20)

Leaf mineral nutrition (K, Ca, Na, Fe, Mn, Zn, Cu)

This paper: Leaf K was consistently lowest under aquaponics alone and highest under Hoagland+Aquaponics with K spray (G-HA-K); foliar K raised K concentration in every nutrient solution including aquaponics (Results 3.4, Fig 9A). Leaf Ca was higher in green than purple basil and rose with foliar K/Fe in most combinations, with the paper’s own Discussion explicitly attributing the aquaponics-vs-Hoagland Ca difference to “the lower calcium content in the aquaponics solution” itself (i.e. a nutrient-solution-composition effect, not a plant-physiological one), matching Table 1’s own water Ca-hardness figures (Aquaponics 32.4 mg/L vs Hoagland 58.4, HA 112.9). Leaf Fe was, unexpectedly, higher in green basil under several Fe-sprayed and non-aquaponic treatments, and foliar K/Fe sprays did not increase leaf Fe concentration in either cultivar (Results 3.4, “Foliar K and Fe sprays had not positive effect on leaf iron concentration,” p.8) — a finding the paper itself flags as counter to the sprays’ intended purpose without further explanation. Leaf Cu was highest under Aquaponics and lowest under Hoagland alone; foliar Fe and K both decreased leaf Cu (Results 3.4, Fig 12). Leaf Zn was higher under Hoagland+Aquaponics than either Aquaponics or Hoagland alone, and higher in green than purple basil (Fig 11).

Compared with:

todo Roosta and Ghorbani 2011 — peppermint/common mint; cited (ref 52) for higher aerial-part Zn under aquaponics than hydroponics but lower Fe and Mn, a mixed pattern the authors say is broadly consistent with (though not identical to) this paper’s basil mineral profile (p.19)
todo Roosta and Arabpour 2013 — two Iranian basil cultivars, hydroponic vs aquaponic; cited (ref 53) for higher leaf Fe and Mn under hydroponics than aquaponics but higher Zn under aquaponics, the same qualitative pattern the authors describe finding here (p.19)
todo Mangeli 2016 — tomato; cited again (ref 40) for higher leaf Fe under hydroponics than aquaponics, matching this paper’s Fe finding, and for the same “low iron in fish waste” mechanism the authors invoke here (p.19)
todo EL-Aila, EL-Sayed and Yassen 2015 — spinach, nano-fertilizer and foliar iron; cited (ref 51) for increased leaf K, N and P with iron application, and for an antagonistic Fe-Zn absorption relationship offered as the mechanism for this paper’s Zn/Fe pattern under aquaponics (p.19)

Linked claims

Citations to chase

Extraction notes

This IS an aquaponics paper, not a hydroponic-only study. The task brief flagged the possibility this might parallel pastorarbuluEnhancingGrowthYield2025 (a genuinely hydroponic-only paper with NA across the whole fish block). On reading the full PDF, that turned out not to apply: this paper stocks real common carp (Cyprinus carpio, 50 fish/m3, 848 L rearing tanks) in an actual recirculating loop (fish tank -> clarifier -> filtration tank -> degassing tank -> plant tank -> back to fish tank) and reports genuine fish-production data (FCR 1.53, 100% survival, mean harvest mass 568.6 g). The design directly compares coupled aquaponics, decoupled “Hoagland+Aquaponics,” and pure Hoagland hydroponics. The fish block is filled with real values (or NR where not stated), never NA.

Trial-count judgment call (two rows, not six or eighteen): The full factorial is 2 cultivars x 3 nutrient solutions x 3 foliar sprays = 18 named cells (e.g. G-A-K, P-HA-Fe), all individually discussed in the Results narrative. However, essentially every quantitative result for growth, pigments, and minerals at the cell level is reported ONLY as a bar chart with Duncan letters — no table, and only a handful of pooled percentage-difference figures in text (Aquaponics vs Hoagland only, not broken out by cultivar or foliar spray). Splitting into 6 rows (by cultivar x nutrient solution, following the precedent in pastorarbuluEnhancingGrowthYield2025) or 18 rows (full factorial) would produce a large number of near-identical all-NR rows differing only in a text label, which SCHEMA.md’s “merging is reversible, splitting is not” guidance argues against absent stated per-cell numeric evidence. The two aquaponic-system arms (coupled Aquaponics, decoupled Hoagland+Aquaponics) are the level at which this paper’s one hard dataset — Table 1’s water chemistry — is actually reported, so trial rows were drawn at that level instead, following the same T1=coupled/T2=decoupled pattern used in mourantianBasilFunctionalGrowth2023 and levizouCircularTriTrophicSystem2025. The cultivar and foliar-spray crossed sub-structure is preserved in each row’s Details/Combination fields and documented in Experimental Remarks, not discarded.

Water quality is this paper’s strongest dataset. Table 1 gives trial means +/- SD for 17 parameters across four solution readings (Hoagland, Hoagland+Aquaponics, Aquaponics-influent, Aquaponics-effluent). Full trials.csv-cell values and the NO-COLUMN remainder (alkalinity, hardness, TDS, NaCl, water K/P/Ca/Fe/Zn/Cu) are in each row’s Experimental Remarks. Aquaponics NO3-N (37.2 influent / 34.8 mg/L effluent) is roughly 5x lower than Hoagland’s (187.05) or HA’s (198.04) — the paper’s own evidence for aquaponic nutrient limitation — yet the SAME paper reports aquaponics-grown basil out-growing Hoagland-grown basil on every pooled metric. This tension is presented in two separate sections of the paper (water chemistry in Methods/Table 1, growth results in Results 3.2) and is never explicitly reconciled by the authors; not flagged as a formal contradiction here since both are independently stated facts about different variables (nutrient concentration vs. growth outcome), not two conflicting values for the same measurement, but worth surfacing for anyone using this paper’s growth claims.

No formal ⚠️ severity flags were raised (quality: ok). No two values in this paper were found stating conflicting figures for the same measurement. Two non-conflict issues are documented in trials.csv Experimental Remarks instead: (1) the essential-oil-yield formula given in Methods appears to be written backwards (dry-sample-mass divided by oil-mass, rather than the reverse) — but since no essential-oil percentage value is ever actually reported anywhere in text or tables, no cell is affected; (2) one feed-protein sentence (“…with a protein content of 50%, due to its balanced amino acid profile and high digestibility can be the primary protein ingredient in most freshwater omnivorous fish diets…”, p.4) reads like generic citation-supported background (citing a paper about a different species/system) rather than a lab-specific formulation value — recorded as stated (50%) but flagged [unclear] in origin.

[not reported] fields, grouped, across both trials:

Fish: Fish Category, SGR, feed N/P/K composition beyond crude protein, % of body weight (daily ration), Total Feed (kg), Fish biomass created (kg), Fish weight gain, Fish trial duration in days (only “6 months” given, an approximate figure not converted to an exact day count), Initial Stock density in kg/m3 (only 50 fish/m3 given, a count-based density, plus a 160-180 g stocking-weight range — converting to kg/m3 would be derivation)
Water: Water recycle (L/min), Water type, Water classification, Daily Water exchange rate, pHOptimal, FUE AP, FUE HYD, WUE, Air supplement — none of these stated anywhere despite the otherwise-detailed Table 1 water panel
Plant: Days Plant after transplant (only “75 days” from foliar-spray initiation given, a different reference point than transplant), Plants/m2, SPAD, Plant height, Leaf count, Plant fresh weight, Plant dry matter, Tissue nitrate AP/HYD (tissue nitrate was never assessed — the paper measured leaf minerals K/Ca/Na/Fe/Mn/Zn/Cu, not nitrate), AP/HYD yield columns — all figure-only or genuinely unmeasured
Site: Lat, Long (city named — Rafsanjan — but no coordinates given anywhere in the paper; not filled from outside knowledge per the prime directive), Average room Temperature (light-phase and dark-phase greenhouse air temperatures given separately, not a single averaged figure), Artificial Lighting, pH Buffers, Air supplement

plant_measurements.csv scope: 14 analytes (SPAD, total chlorophyll, chlorophyll a, chlorophyll b, carotenoids, anthocyanin, essential oil content — all biochemistry; K, Ca, Na, Fe, Mn, Zn, Cu — all mineral) x 2 systems (AP/HYD) x 2 trials = 56 rows, every one NR per SCHEMA.md’s explicit instruction to record bar-chart-only values as NR rows with the reason in Notes, rather than omitting them. Essential oil content does not cleanly fit any of the four defined categories (biochemistry/mineral/microbiology/proximate) — it was filed under biochemistry as the closest fit (a secondary-metabolite/extract measure, analogous to the phenols/antioxidant-capacity examples already in that category), flagged here as a judgment call rather than a clean match. One PDF-extraction curiosity: the Fig 11 (leaf zinc) y-axis label extracts via pdfplumber as reversed/rotated text, )MD gk/gm(nZ, which decodes to “Zn(mg/kg DM)” reversed — i.e. the axis is apparently labelled mg/kg DM. This is an axis LABEL, not a bar value, so it was not used to fill the plant.csv Unit field (kept NR) since it’s a garbled OCR-adjacent artifact rather than a cleanly readable statement, but it’s noted in that row’s Notes for anyone who wants to verify it against the original figure.

Tags judgment call: Meta/Fish/Common-Carp is a NEW tag — no existing note in this vault tags common carp (Cyprinus carpio); introduced following the existing naming convention for other carp-family tags (Meta/Fish/Grass-Carp, Meta/Fish/Koi-Carp, Meta/Fish/Crucian-Carp). Meta/Region/Middle-East reused (Iran, matching albloushiEffectStockingDensity2018, abusinSustainableFoodProduction2020, aljenaidNutrientFilmTechnique2026, alizaehComparingYieldNutrient2025, baniowdehBarleyHordeumVulgare2025). Meta/Plant/Basil reused.

New wikilink targets introduced: H.R. Roosta, S.M.A. Rezaei, M. Raghami (no existing author notes found in the vault, despite Roosta being a very frequently cited author across this vault’s other basil/tomato/mint papers — e.g. mourantianBasilFunctionalGrowth2023 cites “Roosta 2014” as a comparison; no prior note existed to link to). Reused Ocimum basilicum exactly as spelled in mourantianBasilFunctionalGrowth2023. New species link Common carp (Cyprinus carpio), following the vault’s existing [[Species common name (Genus species)]] pattern (e.g. [[Nile tilapia (Oreochromis niloticus)]]).

Relationship to the companion 2011 Roosta & Hamidpour paper: pdfs/Roosta and Hamidpour - 2011 - Effects of foliar application of some macro- and m...pdf is being extracted separately in this same batch by a different agent and was NOT opened or modified here. This 2025 paper cites it directly (ref 12) as a prior foliar-K/Fe-on-tomato-in-aquaponics/hydroponics study by the same corresponding author (H.R. Roosta) — worth cross-checking once both notes exist, since the citation summary in this paper (p.13: aquaponic tomato growth increased with foliar K/Fe, hydroponic tomato unaffected) should be checkable against that paper’s own primary data.

PDF quality: Clean text layer throughout (23 pages, Nature/Scientific Reports single-column layout with inline figures), fully extractable via pdfplumber, no OCR issues for running text. Figures 1-16 are genuine bar charts/heatmaps/biplots in the source PDF (not a text-extraction artifact) — the paper simply does not tabulate its own cell-level growth, pigment, mineral, or essential-oil data anywhere outside the figures, except for the pooled Aquaponics-vs-Hoagland percentage figures and Table 1’s water chemistry. One reference-numbering quirk: several in-text superscript reference numbers for chemical formulas/subscripts (e.g. “NO -” for NO3-, “NO -” for NO2-) render with the subscript digit dropped or misplaced by pdfplumber around Table 1 (p.4) — resolved by cross-referencing the adjacent row labels (“NO-N,” “NO-N,” “NH-N” match “NO3-N,” “NO2-N,” “NH4-N” given the table’s own tolerance-limit column and typical aquaponic water-quality ranges), not a content-loss issue.

Source: Roosta et al. - 2025 - Foliar application of potassium and iron enhances biomass and essential oil production of basil cult.pdf

Data Tables

Structured data extracted from this paper into the vault's trials.csv / plant_measurements.csv datasets. Fields the paper didn't report are omitted. Download the full datasets (measurements).

Trial Parameters

roostaFoliarApplicationPotassium2025-T1

Fish

Field	Value
Fish	Common carp (Cyprinus carpio)
FCR	1.53
Protein	50
Fish size initial	160-180 (range, not a stated mean; p.4)
Fish size final	568.6
Feed routine	Daily (frequency per day not stated, p.4)
Feed regime	Dehulled soybean meal (Glycine max), fed daily; ration (% body weight/day) not stated; feed protein stated as 50% (p.4, wording ambiguous — see Extraction notes)
Fish survival rate	100

Water

Field	Value
Water volume in the system	848 (fish tank only, per system; x3 systems; other components: 60 L clarifier + 60 L filtration tank + 90 L degassing tank + 400 L plant/growth-bed tank per system, Methods p.3-4)
Aq pH	7.68 +/- 0.08 (Aquaponics, influent of growth bed unit, Table 1); effluent 7.66 +/- 0.14
Dissolved Oxigen	6.30 +/- 0.09 (Aquaponics, influent of growth bed unit, Table 1); effluent 6.15 +/- 0.07
EC	0.53 +/- 0.04 (Aquaponics, influent of growth bed unit, Table 1; UNIT CONVERSION ONLY: mS/cm = dS/m); effluent 0.50 +/- 0.03
Water temperature	24.6 +/- 0.92 (Aquaponics, influent of growth bed unit, Table 1); effluent 24.3 +/- 0.81
TAN / NH4-N	0.35 +/- 0.14 (Aquaponics, influent of growth bed unit, Table 1); effluent 0.33 +/- 0.11
NO2-N	1.72 +/- 0.24 (Aquaponics, influent of growth bed unit, Table 1; exceeds the paper’s own stated fish tolerance limit <0.2 mg/L, acknowledged in text p.3); effluent 1.54 +/- 0.21
NO3-N	37.2 +/- 2 (Aquaponics, influent of growth bed unit, Table 1); effluent 34.8 +/- 3

Plant

Field	Value
Plant	Basil (Ocimum basilicum L.), green (Italian large leaf) and purple cultivars
Details	Two cultivars (green, purple) x foliar spray (control / 1000 mg/L K2SO4 / 1000 mg/L FeSO4, twice weekly from 8-leaf stage) crossed within this nutrient-solution trial, not split into separate rows — see TRIAL DEFINITION. 75-day treatment period stated (8-leaf-stage foliar-spray initiation to harvest, p.4).
Plant Category	Aromatic and medicinal crop (p.3)

System & Setup

Field	Value
System type	Substrate culture (70% cocopeat/30% perlite) in pots on floating polystyrene foam rafts within recirculating tanks (p.3-4)
Media Details	20 cm diameter x 20 cm height pots, 5 L volume, 70% cocopeat/30% perlite substrate; 9 plants/pot; 5 cm diameter polystyrene foam rafts suspending pots in the 400 L plant tank (p.3)
Biological system already in use	Y (“The aquaponic unit operated continuously with a known density of fish biomass to maintain stable bacterial populations” (p.4))
Iron supplemented	N (Coupled aquaponic solution sourced directly from fish-tank water only, no added fertilizer (Methods p.3); Table 1 confirms Aquaponics Fe (0.22 mg/L) far below Hoagland (1.15) and HA (1.23))
Remineralization	N (No fertilizer added to the coupled aquaponic loop (Methods p.3))
Climate control	Y (“Greenhouse temperature was controlled using cool air following into greenhouse from central cooler” (p.3); 11h light phase 26+/-3C, 13h dark phase 23+/-3C; RH 53.5+/-5% to 66.5+/-4%; max PPFD above canopy 963 umol/m2/s)
Nutrient supplemented	N (Coupled Aquaponics treatment received no fertilizer amendment, water sourced directly from fish tank (Methods p.3). See COLUMN-FIT NOTE in Experimental Remarks re: the paper’s own foliar K/Fe spray sub-treatment, which is a separate crossed factor not captured by this system-level column.)
Equipment	Leaf area meter (model CI 202); digital caliper (stem diameter); spectrophotometer (model T80 UV/VIS, PG Instruments Ltd) for pigments and anthocyanin; SPAD chlorophyll meter; flame photometer (Jenway, model PFP7) for Na/K; atomic absorption spectrophotometer (GBC-Savant AA, Australia) for Fe/Mn/Zn/Cu; EDTA titration for Mg/Ca; steam-distillation essential-oil extractor; SAS software (statistics)
Control Parameters	Factorial completely randomized design: 2 cultivars (green, purple) x 3 nutrient solutions (Aquaponics, Hoagland, Hoagland+Aquaponics) x 3 foliar sprays (control/K/Fe, 1000 mg/L) = 18 treatment cells, 3 pot-replications/cell, 9 plants/pot (27 plants/cell used for growth analysis; 3 mature leaves/plant, n=3, for biochemical analysis)
Combination	Common carp and basil (green + purple cultivars); coupled aquaponics vs hydroponic (Hoagland), crossed with foliar K/Fe spray

Site

Field	Value
Region	Middle East
Country	Iran

Results & Statistics

Field	Value
Measured Unit	cm (height, internode length); mm via digital caliper (stem diameter); g (fresh/dry mass); cm3, water displacement (root volume); count (leaf/node/branch number); ug/g FM (chlorophyll a/b/total, carotenoids, per stated Porra/Lichtenthaler-Wellburn formulas); % dry matter (essential oil, per stated formula — see Extraction notes on a likely inverted formula)
Statistic Details	Factorial ANOVA (SAS software, 5% significance level); Duncan’s multiple range test, p<0.05; means +/- SE; graphs generated in Excel
Statistically analysed	Y
Replicates (n)	3

Experimental Remarks: TRIAL DEFINITION: T1 = coupled Aquaponics (A) treatment - basil (both cultivars) irrigated directly with fish-tank-derived water via a closed loop (fish tank -> 60 L clarifier -> 60 L filtration tank -> 90 L degassing tank -> 400 L plant tank -> back to fish tank), no fertilizer amendment (Methods p.3: ‘Coupled aquaponic system, where the nutrient solution is directly sourced from the fish tanks’). Paired control = Hoagland (H) hydroponic solution made with distilled water, recorded in the HYD-labelled cells (Methods p.3). Within this trial, two further factors are crossed but NOT split into separate trial rows: cultivar (green Italian large leaf vs purple basil, 9 pots each) and foliar spray (distilled-water control / 1000 mg/L potassium sulfate / 1000 mg/L ferrous sulfate, applied twice weekly from the 8-leaf stage, 6 pots/spray-treatment x 2 cultivars = 18 pots total in this system). This gives 6 named sub-treatment cells (G-A-C, G-A-Fe, G-A-K, P-A-C, P-A-Fe, P-A-K) that the paper names and discusses individually (Figs 1-13), but virtually all of its quantitative results for these cells are reported ONLY as bar charts with Duncan letters — no table and almost no numbers in running text (see NOT DERIVED and NO COLUMN below) — so splitting into 6 rows would produce near-duplicate all-NR rows differing only in a text label. Kept as one row per SCHEMA.md’s ‘if unsure, keep one row’ guidance; the cultivar/foliar sub-structure is preserved in Details/Combination instead. Design: factorial CRD, 2 cultivars x 3 nutrient solutions x 3 foliar sprays = 18 cells, 3 pot-replications/cell (9 plants/pot, 27 plants/cell for growth analysis; n=3 for biochemical/mineral analysis). Same shared fish population/RAS as T2. WATER QUALITY BASIS: Table 1 reports ‘Aquaponics’ water quality as two readings, ‘influent of growth bed unit’ and ‘effluent of growth bed unit’ (before/after the plant tank), not a single trial mean. Influent values (what plants actually receive) are used in each water-quality cell above as the primary figure; effluent values are given alongside in the same cell for reference — this is a before/after pair within Table 1’s single row, not a conflict. UNIT CONVERSION ONLY: EC given in Table 1 as mS/cm; 1 mS/cm = 1 dS/m exactly (equivalent units), recorded directly as dS/m per SCHEMA.md’s EC column definition. NOT DERIVED, left NR: Initial Stock density (50 fish/m3 is a stated density, but in fish/m3 not kg/m3; converting using the 160-180 g stocking-weight RANGE would be derivation from two separately-stated figures, Methods p.4); Fish biomass created (kg) (only final areal production, 28,430 g/m3, and mean harvest mass, 568.6 g, are given — no stated initial total biomass or ‘biomass created’ figure; note internal consistency check: 28,430 / 50 = 568.6 g/fish, exactly matching the paper’s own stated mean harvest mass, so these two figures are self-consistent); Fish weight gain (only initial-weight RANGE, 160-180 g, and final MEAN, 568.6 g, given; a range-to-mean subtraction would be derivation); Total Feed (kg) (FCR 1.53 given, but no total feed consumed figure); Days Plant after transplant (paper states only that ‘the time from the start of [foliar] treatment to the time of plant harvest was 75 days’ (p.4) — measured from the 8-leaf-stage foliar-spray initiation, NOT from the stated transplant point at the 4-leaf stage; the 75-day figure answers a different question than ‘days after transplant’, so is preserved here rather than in that column cell); Plants/m2 (pot/raft layout given, no per-area planting density stated); Water recycle L/min (recirculating pump described qualitatively, no flow rate given); Average room Temperature (paper gives separate light-phase, 26+/-3C, and dark-phase, 23+/-3C, greenhouse air temperatures, not one averaged trial mean; averaging would be derivation). Fish trial duration: paper states carp were ‘cultured for 6 months’ (p.4) — an approximate duration, not an exact day count (months vary 28-31 days), so NOT converted to a day figure; recorded NR in the column, ‘6 months’ preserved here. This is the carp’s own rearing period, distinct from the 75-day plant foliar-treatment period; the paper does not state how the two periods align. [unclear] Feed protein content (50%, p.4): ‘The fish were fed with soy (Glycine max) every day, dehulled soybean meal, with a protein content of 50%, due to its balanced amino acid profile and high digestibility can be the primary protein ingredient in most freshwater omnivorous fish diets and a significant component of the protein composition in many marine fish diets [ref 28, a paper on European sea bass diets]’ — the clause after ‘50%’ reads as generic, citation-supported background on soybean meal as a fish-feed ingredient class, rather than a lab-specific formulation statement, so it is plausible this is boilerplate text rather than a directly assayed value for this trial’s diet. Recorded as stated (50%) since it is the only figure given and grammatically describes ‘the fish’ in this study; flagged as uncertain in origin. No other cell depends on it. COLUMN-FIT NOTE: ‘Iron supplemented’/‘Nutrient supplemented’ below describe the BASE nutrient-solution’s fertilization only (coupled vs decoupled aquaponics, per Methods). This paper’s own primary manipulated factor — foliar spray of 1000 mg/L potassium sulfate or 1000 mg/L ferrous sulfate onto the LEAVES, twice weekly from the 8-leaf stage, applied to 1/3 of pots within EVERY nutrient-solution treatment (a crossed factor, not itself an aquaponic-system property) — has no dedicated SCHEMA.md column; it is described in Details/Combination/TRIAL DEFINITION instead. NO COLUMN (Table 1, all four solution columns: Hoagland / Hoagland+Aquaponics / Aquaponics-influent / Aquaponics-effluent): Total alkalinity 98+/-23 / 253+/-32 / 256+/-52 / 243+/-34 mg/L as CaCO3; Total hardness 68+/-3.2 / 161+/-3.2 / 154+/-4.6 / 158.6+/-7.4 mg/L; TDS 737.2+/-74 / 824.3+/-43 / 312+/-11 / 329+/-19 mg/L; NaCl 0.18+/-0.18 / 1.13+/-0.12 / 1.03+/-0.12 / 0.69+/-0.13 %; water K 115.4+/-5.3 / 129.3+/-2.1 / 24.2+/-4.2 / 22.3+/-2.4 mg/L; water P 18.25+/-1.30 / 21.25+/-2.20 / 9.12+/-0.42 / 8.83+/-0.32 mg/L; water Ca hardness 58.4+/-2.40 / 112.9+/-3.10 / 32.4+/-0.31 / 31.8+/-0.42 mg/L; water Fe 1.15+/-0.08 / 1.23+/-0.06 / 0.22+/-0.03 / 0.22+/-0.02 mg/L; water Zn 0.057+/-0.01 / 0.31+/-0.01 / 0.32+/-0.03 / 0.34+/-0.04 mg/L; water Cu 0.072+/-0.01 / 0.078+/-0.01 / 0.035+/-0.01 / 0.041+/-0.01 mg/L — no dedicated trials.csv column for most of these. Component tank volumes beyond the 848 L fish tank recorded in Water volume in the system: 60 L clarifier, 60 L filtration tank, 90 L degassing tank, 400 L plant/growth-bed tank, per aquaponic system (x3 systems), Methods p.3-4; not summed into one total since the paper never states a single system-total figure. Percent-increase headline figures (Aquaponics vs Hoagland, pooled across cultivar/foliar spray, identical wording in Abstract and Results ‘Vegetative growth’ p.5): plant height +39.81%, internode length +43.32%, stem diameter +30.88%, shoot biomass +40.41%, root biomass +105.43%, leaf number +51.92%, leaf area +51.95%. Cannot be entered into AP/HYD/Plant height/etc. columns — no absolute baseline value is given anywhere for either treatment, only the percentage difference. Essential oil yield formula as stated (Methods, ‘Essential oils’): ‘Essential Oil Yield (%) = (Mass of initial dry plant sample / Mass of extracted essential oil) x 100’ — almost certainly stated backwards (dividing a larger dry-sample mass by a much smaller oil mass would give percentages in the thousands, not the realistic 0.5-1.5% the paper’s own Introduction cites for basil oil content); likely should read (oil mass / dry sample mass) x 100. Does not affect any extracted cell since no essential-oil percentage values are given anywhere in text/tables (Fig 13 is bar-chart only) — flagged as a paper-quality observation only. Page-header year discrepancy: every page footer reads ‘Scientific Reports | (2026) 16:3828’, but Crossref (10.1038/s41598-025-33937-0) records publication year 2025, consistent with the paper’s own ‘Accepted: 23 December 2025’ line; Crossref’s year was used for the citekey/frontmatter per CLAUDE.md.

roostaFoliarApplicationPotassium2025-T2

Fish

Field	Value
Fish	Common carp (Cyprinus carpio)
FCR	1.53
Protein	50
Fish size initial	160-180 (range, not a stated mean; p.4)
Fish size final	568.6
Feed routine	Daily (frequency per day not stated, p.4)
Feed regime	Dehulled soybean meal (Glycine max), fed daily; ration (% body weight/day) not stated; feed protein stated as 50% (p.4, wording ambiguous — see Extraction notes)
Fish survival rate	100

Water

Field	Value
Water volume in the system	848 (fish tank only, per system; x3 systems; other components: 60 L clarifier + 60 L filtration tank + 90 L degassing tank + 400 L plant/growth-bed tank per system, Methods p.3-4)
Aq pH	7.62 +/- 0.05 (Hoagland+Aquaponics, Table 1)
Dissolved Oxigen	6.59 +/- 0.10 (Hoagland+Aquaponics, Table 1)
EC	2.12 +/- 0.18 (Hoagland+Aquaponics, Table 1; UNIT CONVERSION ONLY: mS/cm = dS/m)
Water temperature	24.23 +/- 0.74 (Hoagland+Aquaponics, Table 1)
TAN / NH4-N	0.30 +/- 0.12 (Hoagland+Aquaponics, Table 1)
NO2-N	1.64 +/- 0.03 (Hoagland+Aquaponics, Table 1; exceeds the paper’s own stated fish tolerance limit <0.2 mg/L)
NO3-N	198.04 +/- 18 (Hoagland+Aquaponics, Table 1)

Plant

Field	Value
Plant	Basil (Ocimum basilicum L.), green (Italian large leaf) and purple cultivars
Details	Two cultivars (green, purple) x foliar spray (control / 1000 mg/L K2SO4 / 1000 mg/L FeSO4, twice weekly from 8-leaf stage) crossed within this nutrient-solution trial, not split into separate rows — see TRIAL DEFINITION. 75-day treatment period stated (8-leaf-stage foliar-spray initiation to harvest, p.4).
Plant Category	Aromatic and medicinal crop (p.3)

System & Setup

Field	Value
System type	Substrate culture (70% cocopeat/30% perlite) in pots on floating polystyrene foam rafts within recirculating tanks (p.3-4)
Media Details	20 cm diameter x 20 cm height pots, 5 L volume, 70% cocopeat/30% perlite substrate; 9 plants/pot; 5 cm diameter polystyrene foam rafts suspending pots in the 400 L plant tank (p.3)
Biological system already in use	Y (“The aquaponic unit operated continuously with a known density of fish biomass to maintain stable bacterial populations” (p.4))
Iron supplemented	Y (“Decoupled aquaponic system, which utilizes fish-derived water enriched with additional fertilizers to match the nutrient levels of the hydroponic solution” (p.3); Table 1 HA Fe = 1.23 mg/L, close to pure Hoagland’s 1.15, vs the unenriched Aquaponics-only value of 0.22)
Remineralization	Y (Fish-derived water enriched with additional fertilizers to match Hoagland nutrient target levels (Methods p.3))
Climate control	Y (“Greenhouse temperature was controlled using cool air following into greenhouse from central cooler” (p.3); 11h light phase 26+/-3C, 13h dark phase 23+/-3C; RH 53.5+/-5% to 66.5+/-4%; max PPFD above canopy 963 umol/m2/s)
Nutrient supplemented	Y (Fish-tank water enriched with fertilizer to match Hoagland (hydroponic) nutrient targets before reaching plants (Methods p.3). See COLUMN-FIT NOTE in Experimental Remarks re: the paper’s own foliar K/Fe spray sub-treatment, which is a separate crossed factor not captured by this system-level column.)
Equipment	Leaf area meter (model CI 202); digital caliper (stem diameter); spectrophotometer (model T80 UV/VIS, PG Instruments Ltd) for pigments and anthocyanin; SPAD chlorophyll meter; flame photometer (Jenway, model PFP7) for Na/K; atomic absorption spectrophotometer (GBC-Savant AA, Australia) for Fe/Mn/Zn/Cu; EDTA titration for Mg/Ca; steam-distillation essential-oil extractor; SAS software (statistics)
Control Parameters	Factorial completely randomized design: 2 cultivars (green, purple) x 3 nutrient solutions (Aquaponics, Hoagland, Hoagland+Aquaponics) x 3 foliar sprays (control/K/Fe, 1000 mg/L) = 18 treatment cells, 3 pot-replications/cell, 9 plants/pot (27 plants/cell used for growth analysis; 3 mature leaves/plant, n=3, for biochemical analysis)
Combination	Common carp and basil (green + purple cultivars); decoupled aquaponics (Hoagland+Aquaponics) vs hydroponic (Hoagland), crossed with foliar K/Fe spray

Site

Field	Value
Region	Middle East
Country	Iran

Results & Statistics

Field	Value
Measured Unit	cm (height, internode length); mm via digital caliper (stem diameter); g (fresh/dry mass); cm3, water displacement (root volume); count (leaf/node/branch number); ug/g FM (chlorophyll a/b/total, carotenoids, per stated Porra/Lichtenthaler-Wellburn formulas); % dry matter (essential oil, per stated formula — see Extraction notes on a likely inverted formula)
Statistic Details	Factorial ANOVA (SAS software, 5% significance level); Duncan’s multiple range test, p<0.05; means +/- SE; graphs generated in Excel
Statistically analysed	Y
Replicates (n)	3

Experimental Remarks: TRIAL DEFINITION: T2 = decoupled Hoagland+Aquaponics (HA) treatment - fish-tank-derived water diverted (not returned to the fish tank) and enriched with additional fertilizers to match Hoagland nutrient target levels, delivered alongside the H treatment (Methods p.3: ‘36 pots were transferred to the hydroponic system… 18 [pots] with Aquaponics + Hoagland solution made with aquaponics solution in the aquaponic system’; matches the Introduction’s definition of ‘Decoupled aquaponic system, which utilizes fish-derived water enriched with additional fertilizers to match the nutrient levels of the hydroponic solution’). Same shared carp population/RAS as T1 (Fish-block cells repeated identically in this row). Paired control = Hoagland (H), recorded in the HYD-labelled cells (same H values as T1’s HYD columns, repeated per one-row-per-treatment convention). Same cultivar x foliar-spray crossed sub-structure as T1 (6 named cells: G-HA-C, G-HA-Fe, G-HA-K, P-HA-C, P-HA-Fe, P-HA-K), not split into separate rows for the same reason given in T1 (near-total figure-only reporting at the cell level). Design: same factorial CRD as T1 — see T1 remarks for the full design statement. WATER QUALITY BASIS: unlike ‘Aquaponics’ (T1), Table 1 gives HA water quality as a SINGLE reading (not split influent/effluent), presumably measured once in the HA delivery reservoir before reaching plants. UNIT CONVERSION ONLY: EC given in Table 1 as mS/cm; 1 mS/cm = 1 dS/m exactly, recorded directly as dS/m. NOT DERIVED, left NR: same items as T1 (Initial Stock density, Fish biomass created, Fish weight gain, Total Feed, Days Plant after transplant, Plants/m2, Water recycle, Average room Temperature) — see T1 remarks for full reasoning; identical for this row since it shares the same fish population and greenhouse. Fish trial duration: same ‘6 months’ imprecision as T1, see T1 remarks. [unclear] Feed protein content: same sourcing ambiguity as T1, see T1 remarks. COLUMN-FIT NOTE: same as T1 — ‘Iron supplemented’/‘Nutrient supplemented’ below describe base nutrient-solution fertilization only; the paper’s foliar K/Fe spray sub-treatment (crossed within this trial) has no dedicated column, see T1 remarks for the full note. NO COLUMN (Table 1, Hoagland+Aquaponics column, vs Hoagland alongside for reference): Total alkalinity 253+/-32 vs 98+/-23 mg/L as CaCO3; Total hardness 161+/-3.2 vs 68+/-3.2 mg/L; TDS 824.3+/-43 vs 737.2+/-74 mg/L; NaCl 1.13+/-0.12 vs 0.18+/-0.18 %; water K 129.3+/-2.1 vs 115.4+/-5.3 mg/L; water P 21.25+/-2.20 vs 18.25+/-1.30 mg/L; water Ca hardness 112.9+/-3.10 vs 58.4+/-2.40 mg/L; water Fe 1.23+/-0.06 vs 1.15+/-0.08 mg/L (both far above the unenriched Aquaponics figure of 0.22, consistent with HA’s stated fertilizer enrichment); water Zn 0.31+/-0.01 vs 0.057+/-0.01 mg/L; water Cu 0.078+/-0.01 vs 0.072+/-0.01 mg/L — no dedicated trials.csv column. Same component-volume breakdown as T1 applies (60 L clarifier + 60 L filtration tank + 90 L degassing tank + 400 L plant tank per system, plus the 848 L fish tank recorded in Water volume in the system). HA pots are described as ‘transferred to the hydroponic system’ rather than the closed aquaponic loop, so it is not fully clear from the text whether HA pots physically share the same clarifier/filtration/degassing chain as the coupled Aquaponics pots, or use a separate delivery reservoir fed by aquaponics-sourced water — recorded as UNCLEAR here rather than assumed either way; does not affect any numeric cell (Table 1’s HA figures stand on their own regardless of the exact plumbing). The paper’s percent-increase headline figures (Abstract/Results p.5) describe ‘Aquaponics vs Hoagland’ only and do NOT include HA, so are not repeated as evidence for this T2 row; no equivalent HA-vs-Hoagland percentage summary is given anywhere, only qualitative figure-based statements (e.g., ‘Hoagland + Aquaponics without and with Fe spray… compared to aquaponics alone and controls’ for SPAD, p.7). Same essential-oil-formula and page-header-year observations as T1 apply; see T1 remarks (not repeated in full here).

Plant Measurements

Trial	System	Category	Analyte	Value	Unit	Sig.	Location
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	SPAD index	NR	SPAD units	NR	Fig 6A, p.7
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Total chlorophyll	NR	ug/g FM	NR	Fig 6B, p.7
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Chlorophyll a	NR	ug/g FM	NR	Fig 6C, p.7
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Chlorophyll b	NR	ug/g FM	NR	Fig 7A-C, p.7-8
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Carotenoids	NR	ug/g FM	NR	Fig 8A, p.8
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Anthocyanin content	NR	NR	NR	Fig 8B, p.8
roostaFoliarApplicationPotassium2025-T1	AP	biochemistry	Essential oil content	NR	% dry matter	NR	Fig 13, p.17
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Potassium (K)	NR	NR	NR	Fig 9A, p.7-8
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Calcium (Ca)	NR	NR	NR	Fig 9B, p.7-8
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Sodium (Na)	NR	NR	NR	Fig 9C, p.7-8
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Iron (Fe)	NR	NR	NR	Fig 10A, p.8
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Manganese (Mn)	NR	NR	NR	Fig 10B, p.8
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Zinc (Zn)	NR	NR	NR	Fig 11, p.8-9
roostaFoliarApplicationPotassium2025-T1	AP	mineral	Copper (Cu)	NR	NR	NR	Fig 12, p.8-9
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	SPAD index	NR	SPAD units	NR	Fig 6A, p.7
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Total chlorophyll	NR	ug/g FM	NR	Fig 6B, p.7
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Chlorophyll a	NR	ug/g FM	NR	Fig 6C, p.7
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Chlorophyll b	NR	ug/g FM	NR	Fig 7A-C, p.7-8
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Carotenoids	NR	ug/g FM	NR	Fig 8A, p.8
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Anthocyanin content	NR	NR	NR	Fig 8B, p.8
roostaFoliarApplicationPotassium2025-T1	HYD	biochemistry	Essential oil content	NR	% dry matter	NR	Fig 13, p.17
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Potassium (K)	NR	NR	NR	Fig 9A, p.7-8
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Calcium (Ca)	NR	NR	NR	Fig 9B, p.7-8
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Sodium (Na)	NR	NR	NR	Fig 9C, p.7-8
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Iron (Fe)	NR	NR	NR	Fig 10A, p.8
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Manganese (Mn)	NR	NR	NR	Fig 10B, p.8
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Zinc (Zn)	NR	NR	NR	Fig 11, p.8-9
roostaFoliarApplicationPotassium2025-T1	HYD	mineral	Copper (Cu)	NR	NR	NR	Fig 12, p.8-9
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	SPAD index	NR	SPAD units	NR	Fig 6A, p.7
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Total chlorophyll	NR	ug/g FM	NR	Fig 6B, p.7
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Chlorophyll a	NR	ug/g FM	NR	Fig 6C, p.7
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Chlorophyll b	NR	ug/g FM	NR	Fig 7A-C, p.7-8
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Carotenoids	NR	ug/g FM	NR	Fig 8A, p.8
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Anthocyanin content	NR	NR	NR	Fig 8B, p.8
roostaFoliarApplicationPotassium2025-T2	AP	biochemistry	Essential oil content	NR	% dry matter	NR	Fig 13, p.17
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Potassium (K)	NR	NR	NR	Fig 9A, p.7-8
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Calcium (Ca)	NR	NR	NR	Fig 9B, p.7-8
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Sodium (Na)	NR	NR	NR	Fig 9C, p.7-8
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Iron (Fe)	NR	NR	NR	Fig 10A, p.8
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Manganese (Mn)	NR	NR	NR	Fig 10B, p.8
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Zinc (Zn)	NR	NR	NR	Fig 11, p.8-9
roostaFoliarApplicationPotassium2025-T2	AP	mineral	Copper (Cu)	NR	NR	NR	Fig 12, p.8-9
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	SPAD index	NR	SPAD units	NR	Fig 6A, p.7
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Total chlorophyll	NR	ug/g FM	NR	Fig 6B, p.7
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Chlorophyll a	NR	ug/g FM	NR	Fig 6C, p.7
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Chlorophyll b	NR	ug/g FM	NR	Fig 7A-C, p.7-8
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Carotenoids	NR	ug/g FM	NR	Fig 8A, p.8
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Anthocyanin content	NR	NR	NR	Fig 8B, p.8
roostaFoliarApplicationPotassium2025-T2	HYD	biochemistry	Essential oil content	NR	% dry matter	NR	Fig 13, p.17
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Potassium (K)	NR	NR	NR	Fig 9A, p.7-8
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Calcium (Ca)	NR	NR	NR	Fig 9B, p.7-8
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Sodium (Na)	NR	NR	NR	Fig 9C, p.7-8
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Iron (Fe)	NR	NR	NR	Fig 10A, p.8
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Manganese (Mn)	NR	NR	NR	Fig 10B, p.8
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Zinc (Zn)	NR	NR	NR	Fig 11, p.8-9
roostaFoliarApplicationPotassium2025-T2	HYD	mineral	Copper (Cu)	NR	NR	NR	Fig 12, p.8-9

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Foliar application of potassium and iron enhances biomass and essential oil production of basil cultivated in aquaponics and hydroponics

Foliar application of potassium and iron enhances biomass and essential oil production of basil cultivated in aquaponics and hydroponics

Metadata

Abstract

Summary

Nutrient-solution comparison (coupled vs decoupled vs hydroponic)

Foliar potassium and iron supplementation

Leaf mineral nutrition (K, Ca, Na, Fe, Mn, Zn, Cu)

Linked claims

Citations to chase

Extraction notes

Data Tables

Trial Parameters

roostaFoliarApplicationPotassium2025-T1

roostaFoliarApplicationPotassium2025-T2

Plant Measurements

Graph View

Table of Contents

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