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Comparative Cultivation and Biochemical Analysis of Spinacia oleraceae Grown in Aquaponics, Hydroponics and Field Conditions

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tagsmeta/type/exploratory, meta/region/south-asia, meta/fish/guppy, meta/plant/spinach

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Comparative Cultivation and Biochemical Analysis of Spinacia oleraceae Grown in Aquaponics, Hydroponics and Field Conditions

Metadata

  • Cite key: ranawadeComparativeCultivationBiochemical2017
  • Item type: Journal Article
  • Authors: P.S. Ranawade, S.D. Tidke, A.K. Kate
  • Affiliation: Modern College of Agricultural Biotechnology, Pune, India (all authors)
  • Journal: International Journal of Current Microbiology and Applied Sciences 6(4) (2017) 1007-1013
  • Date: Accepted 12 March 2017; available online 10 April 2017
  • Date added: 2026-08-10
  • DOI: 10.20546/ijcmas.2017.604.124 — see Extraction notes for a conflict with the paper’s own self-citation block
  • Funding: Not stated in the paper
  • URL: https://doi.org/10.20546/ijcmas.2017.604.124
  • PDF: S.D. Tidke and Kate - 2017 - Comparative Cultivation and Biochemical Analysis o.pdf

Opinion

A short, DIY-scale proof-of-concept comparing spinach grown in a homemade bottle-and-bamboo aquaponic/hydroponic rig against a soil-bed traditional control, with no replication, no statistical test, and no dispersion (SD/SE) reported for any measurement — squarely exploratory rather than experiment. The redeeming feature is unusually clean internal consistency: every figure (germination day, height, surface area, yield, protein/carbohydrate/chlorophyll %) matches exactly across the Abstract, Results text, and the Graph 1/Graph 2 data tables, including two-harvest yield sub-totals that sum correctly. The two things that would need checking before citing this paper: (1) its own “How to cite” block on the last page prints a DOI that resolves to a completely different, unrelated article (a Capsicum/NPK study) — the DOI printed on page 1 is the one that actually matches this paper’s title and authors, and was used here; (2) the paper’s yield figures (Kg/acre) are described as “calculated by L x B” (length x breadth) with no stated units or area-to-mass conversion, so despite being internally consistent they are not transparently a directly-weighed harvest mass. The aquaponic and hydroponic treatments also used different growing media throughout (perlite vs sphagnum moss) in addition to their different nutrient sources, an uncontrolled confound the authors do not address. Useful as a low-cost DIY-system data point and nothing more; not suited to any quantitative synthesis that needs dispersion or replication.

Abstract

Comparison between aquaponics, hydroponics and traditional method for cultivation of spinach was carried out. In this study, spinach was grown in the soilless media like perlite and sphagnum moss. Medias were used to support plant growth. From these Media the perlite media was used in aquaponics and sphagnum moss was used in hydroponics. This study was carried out to examine different morphological characters like height, germination period, surface area, yield of spinach, and biochemical analysis like protein, carbohydrate, chlorophyll content. The height and surface area of the traditionally cultivated spinach (Height- 23 cm) (Surface area- 79 sq.cm) was more than the hydroponically (Height- 18 cm) (Surface area- 70 sq.cm) and aquaponically (Height- 20.5) (Surface area- 72 sq.cm) cultivated spinach. But the germination period of aquaponically and hydroponically cultivated spinach (4th day) was earlier than traditionally cultivated spinach (5th day). The protein and carbohydrate content was more in aquaponically (Protein - 2.9%), (Carbohydrate - 3.9) and hydroponically (Protein - 2.7%), (Carbohydrate - 3.8) cultivated spinach than traditionally (Protein - 2.6%), (Carbohydrate - 3.8) cultivated spinach. Chlorophyll content was highest (0.07%) in the traditionally grown spinach and (0.06%) in aquaponically as well as hydroponically grown spinach. In traditionally and hydroponically cultivated spinach, plants were provided with all the nutritional requirements externally but in aquaponics nutrients were provided naturally through fish excrete. In hydroponics nutrient requirement was less compared to traditional method. In this work, guppy fishes were used in aquaponics as a source of nutrients. For hydroponics, the N: P: K fertilizer named 19:19:19 was given in small quantities. For traditionally cultivated spinach the fertilizers like Urea, 19:19:19 and 15:15:15 were applied. The yield of the aquaponically cultivated spinach was measured (4455Kg/acre); it was slightly more than hydroponically cultivated spinach (3780 Kg/acre) and much more than the traditionally cultivated spinach (1615 Kg/acre).

Summary

Ranawade, Tidke and Kate built a low-cost, DIY aquaponic and hydroponic rig from cut plastic bottles mounted on bamboo frames, and used it to grow spinach (Spinacia oleracea ‘All Green’) under three conditions: aquaponics (perlite-media cups, guppy fish as sole nutrient source), hydroponics (sphagnum-moss cups, 19:19:19 NPK solution), and a traditional soil bed (Urea + 19:19:19 + 15:15:15 fertilizer). Each treatment was harvested twice (day 45 and day 60) and assessed for germination time, plant height, leaf surface area, an area-derived “yield” figure (Kg/acre), and three biochemical endpoints (protein, carbohydrate, chlorophyll content, all in %). No replicate systems, sample sizes, or statistical tests are reported anywhere — every value reads as a single measurement or system total. Aquaponic and hydroponic spinach germinated a day earlier than the traditional plants (day 4 vs day 5) but ended up shorter (20.5 cm and 18 cm vs 23 cm) and with smaller leaf surface area (72 and 70 sq.cm vs 79 sq.cm) at day 60. Yield was highest in aquaponics (4455 Kg/acre), then hydroponics (3780 Kg/acre), then traditional (1615 Kg/acre) — roughly 2.8x higher in aquaponics than in soil. Protein and carbohydrate content were both marginally higher in aquaponic and hydroponic spinach than traditional, while chlorophyll content was marginally higher in the traditionally grown spinach. The authors conclude aquaponics and hydroponics are more water- and nutrient-efficient and more productive than traditional soil cultivation, though the paper does not statistically test any of these differences.

Experiment data

  • Location: Not stated as a trial site; institutional affiliation is Modern College of Agricultural Biotechnology, Pune, India. Supplies sourced from local market (Naik Krushi Bhandar, Pune), a fishery shop in Phaltan, Dist. Satara (guppy fish, D-klor), and Paud, Pune (fish food).
  • Design: Three single, unreplicated growing systems — aquaponic (DIY bottle assembly, perlite media, guppy fish), hydroponic (DIY bottle assembly, sphagnum moss, 19:19:19 NPK solution), and traditional (soil ridge-and-furrow bed, Urea/19:19:19/15:15:15). No stated replicate count, no randomization language, no statistical test.
  • Replicates / n: Not reported for any treatment.
  • Duration: Two harvests per treatment, at 45 and 60 days after direct sowing (no transplant step).
  • Organisms: Spinach (Spinacia oleracea) (‘All Green’ variety) / Guppy (Poecilia reticulata) (spelled “Pocelia reticulata” in the paper)
  • Statistics: None — no test, software, or dispersion (SD/SE) reported anywhere in the paper.
  • Yield: Aquaponic 4455 Kg/acre > Hydroponic 3780 Kg/acre > Traditional 1615 Kg/acre (sum of two harvests each; figures internally consistent across Abstract, Results, and Graph 1).
  • Biochemistry (all %, basis fresh/dry not stated): Protein AP 2.9 > HYD 2.7 > Traditional 2.6; Carbohydrate AP 3.9 > HYD 3.8 = Traditional 3.8; Chlorophyll Traditional 0.07 > AP 0.06 = HYD 0.06.

Yield and growth

This paper: Aquaponic spinach produced the highest area-derived yield (4455 Kg/acre), ahead of hydroponics (3780 Kg/acre) and well ahead of traditional soil cultivation (1615 Kg/acre); the same ranking held at both the 45-day and 60-day harvests individually. Despite the higher yield figure, aquaponic and hydroponic plants were shorter (20.5 cm and 18 cm vs 23 cm) and had smaller leaf surface area (72 and 70 sq.cm vs 79 sq.cm) than traditional plants at day 60 — the paper attributes the reduced height/area to more restricted root development in the soilless cup systems, without explaining the apparent tension with the higher “yield” figure for the same plants. Germination was one day earlier in both soilless systems (day 4) than traditional (day 5), attributed to more direct root access to water and nutrients.

Compared with: (no external literature comparison given for growth/yield figures specifically; discussion is limited to restating the paper’s own numbers)

Biochemical composition

This paper: Protein (Folin-Lowry method) and carbohydrate (Anthrone method) content were both marginally higher in aquaponic spinach (2.9%, 3.9%) than hydroponic (2.7%, 3.8%) and traditional (2.6%, 3.8%), which the authors attribute generically to the aquaponic nutrient source without further mechanistic explanation. Total chlorophyll (Arnon method, spectrophotometric) showed the opposite pattern — highest in traditionally grown spinach (0.07%) and equal in aquaponic/hydroponic spinach (0.06% each). No basis (fresh vs dry weight) is stated for any of the three percentages, and no statistical test was applied to any comparison.

Compared with: (no external literature comparison given for the biochemical results specifically)

Linked claims

Citations to chase

  • todo Al-Karaki, G. and Al-Hashimi, M. (2012) — Green fodder production and water use efficiency of some forage crops under hydroponic conditions, Int. Scholarly Res. Network 12(12):1-5
  • todo Hambrey, J. (2013) — The relevance of aquaponics to the New Zealand aid programme, Ministry of Foreign Affairs and Trade, 6-92 — cited for the “~70% of fish-feed nutrients captured” claim
  • todo Diver, S. (2006) — Aquaponics: Integration of hydroponics with aquaculture, National Sustainable Agriculture Information Service, 1-28
  • todo Cavanagh (2008) — source of the L x B / L2 yield-calculation method used in this paper’s Methods (p.1010); not resolvable to a full citation from this paper’s reference list, which does not include a “Cavanagh” entry — see Extraction notes

Extraction notes

Type classification: Recorded as exploratory. The paper reports controlled, self-collected data (SCHEMA.md’s primary-research test is met), but there is no stated replication of any treatment (each of the three systems appears to be a single unreplicated setup), no randomization, and no statistical test of any kind — no ANOVA, no p-values, no significance letters, and no dispersion (SD/SE) for a single measurement in the entire paper. This is a clean match for SCHEMA.md’s exploratory test (“descriptive, typically unreplicated, no formal hypothesis test”) and a clear miss for experiment’s replication/statistical-comparison requirement.

Paper ID / first-author judgment call: The PDF filename in this vault is S.D. Tidke and Kate - 2017 - ..., dropping the actual first author. Both the PDF’s own byline (p.1007: “P.S. Ranawade1, S.D. Tidke1* and A.K. Kate2”) and the Crossref record for DOI 10.20546/ijcmas.2017.604.124 list P.S. Ranawade first. Per CLAUDE.md’s rule that Paper ID uses “first author surname… from the paper’s own metadata,” this note uses ranawadeComparativeCultivationBiochemical2017, not the tidke... form the filename might suggest. This should be checked against the Zotero library entry for this item at the next batch/merge step, since it may indicate a creator-order data-entry error in Zotero for this specific record.

⚠️MATERIAL — DOI conflict (metadata only, does not affect any trials.csv/plant.csv data cell and is not counted toward the quality score, which SCHEMA.md scopes to trial data contradictions). Page 1 header of the PDF prints https://doi.org/10.20546/ijcmas.2017.604.124. The paper’s own “How to cite this article” block on the final page (p.1013) instead prints https://doi.org/10.20546/ijcmas.2017.604.125. Crossref lookups: .124 resolves to a record with this paper’s exact title and author list (Ranawade/Tidke/Kate, Spinacia oleraceae) but a mismatched page range (987-1006 instead of the 1007-1013 actually printed here). .125 resolves to a completely different article by different authors (Dubey, Singh, Rajput, Kumar, Verma, Chandraker — “Effect of NPK on Plant Growth, Yield and Quality of Capsicum…under Shade Net Condition”), which happens to carry the correct page range (1007-1013) for this issue. Title/author match is the stronger identity signal, so .124 was used as this paper’s DOI throughout. This looks like a publisher/Crossref-side DOI-to-pagination registration error rather than a PDF-scanning problem, but it means a reader following this paper’s own self-citation block lands on an unrelated Capsicum paper — worth flagging prominently.

[unclear] — Yield calculation method. Methods (p.1010) states only: “Yield was calculated by L2 for traditionally grown spinach and hydroponics, aquaponics by L x B where, L = length, B = breadth (Cavanagh, 2008).” L and B are never defined with units, and no formula or conversion factor connecting a length x breadth calculation to a mass-per-area figure (Kg/acre) is given. The “Cavanagh, 2008” citation is not present in the paper’s own Reference list, so the method cannot be chased down from this paper alone. The resulting Kg/acre values (AP 4455, HYD 3780, Traditional 1615) are recorded as reported because they are internally consistent everywhere they appear (Abstract, Results, and Graph 1’s per-harvest breakdown, which sums correctly: 2100+2355=4455, 1830+1950=3780, 785+830=1615), but readers should not assume this is a directly weighed harvest mass.

Design confound, not a numeric contradiction: the aquaponic and hydroponic treatments used different growing media (perlite vs sphagnum moss, p.1009) in addition to their different nutrient sources, and the paper never discusses or controls for this. Any AP-vs-HYD difference in this dataset could be a media effect, a nutrient-source effect, or both.

[not reported] fields, grouped:

  • Fish: Fish Category, Initial Stock density, FCR, SGR, feed N/P/K composition, % of body weight ration, Fish size initial/final, Feed routine (frequency), Total Feed (kg), Fish biomass created (kg), Fish survival rate, Fish weight gain, Fish trial duration (days) — no fish count, individual/aggregate weight, feed quantity, feed composition beyond the generic label “Fish food,” or survival/mortality figure is given anywhere; guppies are a nutrient source only, never a measured endpoint.
  • Water: Water recycle, Water volume in the system, Water type, Water classification, Daily Water exchange rate, Aq pH, pHOptimal, FUE AP/HYD, WUE, Dissolved Oxygen, EC, Water temperature, TAN/NH4-N, NO2-N, NO3-N — no water-chemistry values of any kind are reported; “water rotation was done after several days intervals” (p.1009) is the only water-management detail and is too vague to record as a rate.
  • Plant: Plant Category, Plants/m2, SPAD (aquaponics), Leaf count, Plant fresh weight, Plant dry matter, Tissue nitrate AP/HYD — not measured. Chlorophyll was assessed spectrophotometrically (Arnon method) rather than with a SPAD meter, and no leaf-tissue nitrate assay was performed.
  • Site: Average room Temperature, Lat, Long — no coordinates or ambient temperature are given, only supply-sourcing locations (Pune market, Phaltan/Satara fishery, Paud feed supplier). Region/Country were taken from the stated institutional affiliation rather than a stated trial site.
  • Presence/absence columns: Biological system already in use, Air supplement, pH Buffers, Climate control, Artificial Lighting — none of these practices are mentioned in either direction for the aquaponic treatment, so left NR rather than assumed N.
  • Funding — not stated anywhere in the paper.

Days Plant after transplant recorded NA, not NR: spinach was direct-seeded into the perlite/sphagnum cups and never transplanted, so the column’s transplant-based counting basis does not apply to this design (per SCHEMA.md’s NA convention for design mismatches). The comparable harvest-from-sowing days (45 and 60) are recorded in the Details column instead.

NO COLUMN items (see trials.csv Experimental Remarks for the exact figures): the full traditional/field-soil arm (height 23 cm, leaf surface area 79 sq.cm, germination day 5, yield 1615 Kg/acre, protein 2.6%, carbohydrate 3.8%, chlorophyll 0.07%) — this is a third, non-aquaponic reference arm with no AP/HYD column home in trials.csv, so it is preserved in remarks rather than forced into a row; it is however captured as a third System label (“Field”) in plant.csv for the biochemical analytes, since plant_measurements.csv permits “another treatment label used in that paper.” Hydroponic-side plant height (18 cm at day 60; trials.csv’s single Plant height column holds only the AP value, 20.5 cm, per the convention established in pantanellaAquaponicsHydroponicsProduction2012). Intermediate height/surface-area readings at days 10-50 (Graph 1) — time-series points, not trial means.

plant_measurements.csv category judgment call: Protein was categorized proximate (an explicit example in SCHEMA.md’s proximate list). Carbohydrate was categorized biochemistry rather than proximate: it was measured by the Anthrone method, a colorimetric glucose-equivalent assay closer to a soluble-carbohydrate/sugars determination than a proximate carbohydrate-by-difference figure, and SCHEMA.md’s biochemistry category explicitly lists “sugars” while its proximate list does not mention carbohydrate at all. Total chlorophyll was categorized biochemistry (an explicit example in SCHEMA.md’s list) and is a spectrophotometric (Arnon-method) measurement, not a SPAD-meter reading, so it was not routed to the trials.csv SPAD column. No SD is reported for any of the nine plant.csv rows — the paper gives single point values throughout, with no replication or dispersion measure for anything.

MINOR (do not affect quality score): the paper spells the guppy species “Pocelia reticulata” throughout (Introduction, p.1008); corrected to the standard binomial Poecilia reticulata in the Fish cell, noted here for the record. The Arnon-method chlorophyll citation is given as “Rajlakshmi and Banu, 2008” in-text (p.1010) but as “Rajalakshmi, K. and Banu, A. 2013” in the References (p.1013) — a reference-list inconsistency (year and spelling), not a data conflict; no cell affected.

Tags judgment call: Tagged Meta/Fish/Guppy (new tag facet value; guppy, Poecilia reticulata, is the sole aquaculture organism, used purely as a nutrient source) and Meta/Plant/Spinach (reusing the existing tag from atiqueAquaponicsBeneficialTerms2022 and delgadoCouplingAquaponicSystems2023, since this is true spinach, Spinacia oleracea — distinct from “Indian spinach”/Basella alba in akterComparisonIndianSpinach2025, which is tagged separately). Meta/Region/South-Asia matches the convention already used by akterComparisonIndianSpinach2025 for an Indian-subcontinent paper. Meta/Type/Exploratory is a new value under the existing Meta/Type/ facet (not a new facet), matching SCHEMA.md’s controlled-vocabulary exploratory type, which had no prior instance in this vault’s notes/ folder.

New wikilink targets introduced: P.S. Ranawade, S.D. Tidke, A.K. Kate (no existing author notes found in the vault), Spinach (Spinacia oleracea) (new; distinct from any existing “Indian spinach” concept note), Guppy (Poecilia reticulata) (new).

PDF quality: Clean text layer throughout (7 pages, standard IJCMAS single/two-column layout), fully extractable, no OCR issues. Two embedded bar-chart graphs (Graph 1: morphological parameters; Graph 2: biochemical parameters) both include full data-table legends beneath the charts, so no figure-only values had to be left NR — every plotted value is also given as text in the chart’s own data table.

Source: S.D. Tidke and Kate - 2017 - Comparative Cultivation and Biochemical Analysis o.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

ranawadeComparativeCultivationBiochemical2017-T1

Fish

FieldValue
FishGuppy (Poecilia reticulata)
Feed regimeUnspecified commercial ‘Fish food’ sourced from Paud, Pune (p.1009, Sample collection); no brand, composition, or feeding rate/frequency stated. D-klor (a chlorine-removal product) was also collected from a Pune fishery shop but its use in the trial itself is never described in Methods.

Plant

FieldValue
PlantSpinach (Spinacia oleracea, ‘All Green’ variety)
DetailsDirect-seeded into perlite-filled cups (AP) or sphagnum-moss-filled cups (HYD) mounted in cut holes on plastic bottles supported by a bamboo frame; bottles one-third filled with water so the cup base sits 1-2 cm submerged. Two harvests, at 45 and 60 days after sowing (p.1009-1010). ‘All Green’ variety.
Plant height20.5

System & Setup

FieldValue
System typeDIY bottle-based media-bed aquaponic system: plastic bottles mounted on a bamboo frame with ~7 sq.cm cup openings; perlite-media cups sit with base 1-2 cm submerged in water shared directly with guppy fish — no separate fish tank or biofilter compartment described (p.1009).
Media DetailsPerlite media, AP cups, ~7 sq.cm opening (p.1009); sphagnum moss, HYD cups, ~4 cm diameter opening (p.1009).
Iron supplementedN (AP received no external nutrient input beyond fish excrete (‘nutrients were provided naturally through fish excrete’, Abstract p.1007; Methods p.1009 describes no fertilizer or micronutrient addition to the aquaponic bottles). The Fe/Mn/Zn/Cu/Mo/B micronutrients purchased (p.1009, Sample collection) were used in the hydroponic nutrient solution only, per Methods’ explicit statement that ‘macronutrients and micronutrients were supplied to hydroponics.’)
RemineralizationN (Same basis as Iron supplemented — AP water was not remineralized/fertilized externally; only fish waste and a periodic, undefined ‘water rotation’ (p.1009).)
Nutrient supplementedN (AP explicitly received no external nutrient supplementation — ‘in aquaponics nutrients were provided naturally through fish excrete’ (p.1007 Abstract; consistent with Introduction p.1008 and Methods p.1009).)
EquipmentGrid paper method for leaf area estimation (Pandey & Singh 2011); Folin-Lowry method for protein (Sadasivam & Manickam 2008); Anthrone method for carbohydrate; Arnon method (spectrophotometric formula using A645/A663 absorbance) for total chlorophyll, cited in-text as ‘Rajlakshmi and Banu, 2008’ but listed in the References as ‘Rajalakshmi, K. and Banu, A. 2013’ (citation year/spelling mismatch, not a data conflict). No instrument brand or model is given for any assay.
CombinationGuppy (Poecilia reticulata) and spinach (Spinacia oleracea ‘All Green’) in a DIY bottle-based aquaponic system; compared against sphagnum-moss NPK hydroponics and soil-based traditional field cultivation as a third, non-aquaponic reference arm not captured in the AP/HYD column structure (see Experimental Remarks).

Site

FieldValue
RegionSouth Asia
CountryIndia

Results & Statistics

FieldValue
Measured UnitKg/acre (yield, Graph 1); cm (plant height, Graph 1); sq.cm (leaf surface area, Graph 1); days (germination period, Graph 1); % (protein, carbohydrate, chlorophyll content, Graph 2) — basis (fresh vs dry weight) not stated for the % biochemical values.
Statistic DetailsNone stated — no statistical test, software, replicate count, or dispersion (SD/SE) is reported anywhere in the paper; every reported value reads as a single point measurement/system total (p.1007-1012).
Statistically analysedN
AP4455
HYD3780

Experimental Remarks: TRIAL DEFINITION: T1 = the paper’s single aquaponic treatment (spinach in perlite-media cups sharing water directly with guppy fish, DIY bottle assembly) vs its paired hydroponic control (spinach in sphagnum-moss cups fed 19:19:19 NPK solution ‘with suitable EC’, same bottle/bamboo assembly). This is the paper’s only aquaponic arm; a third, non-aquaponic ‘traditional’ field-soil arm (Ridges-and-Furrow beds, fertilized with Urea/19:19:19/15:15:15) was also run for comparison but has no AP/HYD column home and is recorded under NO COLUMN below rather than as a second trial row, since it is neither the aquaponic treatment nor its hydroponic control. | DOI CONFLICT (metadata, not a trial data cell — does not count toward quality scoring): the PDF’s own page-1 header prints DOI https://doi.org/10.20546/ijcmas.2017.604.124, but the paper’s own ‘How to cite this article’ block on the final page (p.1013) instead prints https://doi.org/10.20546/ijcmas.2017.604.125. Crossref lookups for both: 604.124 resolves to a record with this exact title and author list (Ranawade/Tidke/Kate, Spinacia oleraceae) but a mismatched page range (987-1006 vs the 1007-1013 actually printed on this PDF). 604.125 resolves to an entirely different article by different authors (Dubey et al., ‘Effect of NPK on…Capsicum…’), which nonetheless carries the correct page range (1007-1013) for this issue. Title/author match is the stronger identity signal, so 604.124 was used as this paper’s DOI; the discrepancy is very likely a publisher-side DOI/pagination registration error in this journal, not evidence that either paper is mis-scanned. Recorded in full since a reader following the PDF’s own self-citation block would land on the wrong article. | FIRST-AUTHOR / PAPER ID JUDGMENT CALL: the PDF’s byline (p.1007) and Crossref both list P.S. Ranawade first, S.D. Tidke second, A.K. Kate third. The vault’s PDF filename (‘S.D. Tidke and Kate - 2017 - …’) drops Ranawade and lists Tidke first — apparently a Zotero creator-order/data-entry artifact for this item, not a reflection of the published byline. Per CLAUDE.md’s rule (first author surname from the paper’s own metadata), Paper ID was generated from the confirmed byline/Crossref order as ranawadeComparativeCultivationBiochemical2017, NOT tidkeComparativeCultivationBiochemical2017. Flagged for verification against the Zotero library entry at the next batch merge. | YIELD METHODOLOGY [unclear]: ‘Yield was calculated by L2 for traditionally grown spinach and hydroponics, aquaponics by L x B where, L = length, B = breadth (Cavanagh, 2008)’ (Methods, p.1010) — L and B are never defined as plant/bed dimensions with explicit units, and the paper never shows how a length x breadth calculation converts to a mass figure in Kg/acre; no conversion factor or formula linking area to weight is given anywhere. The Kg/acre yield figures (AP 4455, HYD 3780) are recorded as literally reported since they are internally consistent across Abstract, Results, and the two-harvest Graph 1 breakdown (785+830=1615 traditional; 2100+2355=4455 aquaponic; 1830+1950=3780 hydroponic — all sum correctly), but the underlying calculation is opaque and should not be assumed equivalent to a directly weighed harvest yield. | MEDIA CONFOUND (design limitation, not a numeric contradiction): the AP and HYD treatments used different growing media throughout (perlite for AP, sphagnum moss for HYD, p.1009) alongside their different nutrient sources — media type and nutrient source are fully confounded in this design, and the paper does not discuss or control for this. Any AP-vs-HYD difference could reflect the media rather than (or in addition to) the nutrient-source comparison the paper frames as its subject. | NOT DERIVED, left NR (paper never states, per no-derivation rule): Fish Category, Initial Stock density, FCR, SGR, feed N/P/K composition, % of body weight ration, Fish size initial/final, Feed routine (frequency), Total Feed (kg), Fish biomass created (kg), Fish survival rate, Fish weight gain, Fish trial duration (days) — the paper never states a fish count, individual or aggregate fish weight, feed quantity, feed composition beyond the vague label ‘Fish food’, or any survival/mortality figure for the guppies; guppies are treated purely as a nutrient source, never as a measured endpoint. Water recycle, Water volume in the system, Water type, Water classification, Daily Water exchange rate, Aq pH, pHOptimal, FUE AP/HYD, WUE, Dissolved Oxygen, EC, Water temperature, TAN/NH4-N, NO2-N, NO3-N — no water-chemistry values of any kind are reported for either treatment; ‘water rotation was done after several days intervals’ (p.1009) is the only water-management detail given and is too vague to record as a rate. Plant Category, Plants/m2, SPAD (aquaponics), Leaf count, Plant fresh weight, Plant dry matter, Tissue nitrate AP/HYD — not measured; chlorophyll was assessed spectrophotometrically (Arnon method) rather than by SPAD meter, and no leaf-tissue nitrate assay was performed. Average room Temperature, Lat, Long — no experimental-site coordinates or ambient temperature given (only supply-sourcing locations: Pune market, Phaltan/Satara fishery, Paud feed supplier); Region/Country taken from the stated institutional affiliation (Modern College of Agricultural Biotechnology, Pune, India) rather than a stated trial site. Biological system already in use, Air supplement, pH Buffers, Climate control, Artificial Lighting — none of these practices are mentioned in either direction (present or absent) for the AP treatment. Days Plant after transplant recorded NA rather than NR: spinach was direct-seeded into the media cups, never transplanted, so the column’s transplant-based counting basis does not apply to this design; the comparable harvest-from-sowing days (45 and 60) are given in Details instead. | NO COLUMN (third, non-aquaponic ‘traditional’ field arm, and other figures with no schema home): Traditional/field spinach (soil beds, Urea + 19:19:19 + 15:15:15 fertilizer) — height 23 cm, leaf surface area 79 sq.cm, germination day 5, yield 1615 Kg/acre (785 + 830 across two harvests), protein 2.6%, carbohydrate 3.8%, chlorophyll 0.07% (all at day 60/final harvest unless noted; Graphs 1-2, p.1011-1012). HYD-side plant height at day 60: 18 cm (the Plant height cell above holds the AP value only, 20.5 cm, per vault convention established in pantanellaAquaponicsHydroponicsProduction2012). Intermediate height and surface-area readings at days 10/20/30/40/50 for all three systems (Graph 1, p.1011) — time-series points, not trial means, not extracted per SCHEMA.md’s water-quality summary-value convention extended here to these morphological time series. Fish sourcing: guppy (Poecilia reticulata) sourced from a fishery shop in Phaltan, Dist. Satara; feed sourced separately from Paud, Pune; a chlorine-removal product (‘D-klor’) was also purchased (p.1009) but its application is never described in Methods. | MINOR: the paper spells the guppy species ‘Pocelia reticulata’ throughout (Introduction p.1008); corrected to the standard binomial Poecilia reticulata in the Fish cell. Also MINOR: the Arnon-method chlorophyll citation is given as ‘Rajlakshmi and Banu, 2008’ in-text (p.1010) but as ‘Rajalakshmi, K. and Banu, A. 2013’ in the References (p.1013) — a reference-list inconsistency (year and spelling), not a data conflict; no cell affected. Neither MINOR item affects the quality score per SCHEMA.md (MINOR never counts). | INTERNAL CONSISTENCY (for the record, not a flag): every one of this paper’s numeric results (germination day, height, surface area, yield, protein %, carbohydrate %, chlorophyll %) matches exactly across the Abstract, the Results running text, and the corresponding Graph 1/Graph 2 data table for all three treatments — including the two-harvest yield sub-totals summing correctly to the stated totals. This is unusually clean internal agreement for a paper in this vault; the only substantive issues found are the DOI/citation-block conflict and the undocumented yield-calculation method noted above.

Plant Measurements

TrialSystemCategoryAnalyteValueUnitSig.Location
ranawadeComparativeCultivationBiochemical2017-T1APproximateProtein2.9%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1APbiochemistryCarbohydrate3.9%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1APbiochemistryTotal chlorophyll0.06%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1HYDproximateProtein2.7%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1HYDbiochemistryCarbohydrate3.8%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1HYDbiochemistryTotal chlorophyll0.06%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1FieldproximateProtein2.6%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1FieldbiochemistryCarbohydrate3.8%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)
ranawadeComparativeCultivationBiochemical2017-T1FieldbiochemistryTotal chlorophyll0.07%NRGraph 2 p.1012; also stated in Abstract p.1007 and Results p.1012 (all sources agree)

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