Quartz 5

Barley (Hordeum vulgare L.) productivity and nutritive value in aquaponic versus hydroponic systems

Properties1
tagsmeta/type/experiment, meta/region/middle-east, meta/fish/tilapia, meta/plant/barley

25 min read

Barley (Hordeum vulgare L.) productivity and nutritive value in aquaponic versus hydroponic systems

Metadata

  • Cite key: baniowdehBarleyHordeumVulgare2025
  • Item type: Journal Article
  • Authors: A. Bani Owdeh, M. Salman, M. Chikha, M. Salah Romdhane
  • Affiliation: Aquatic Ecosystems and Resources Laboratory, National Institute of Agricultural Sciences, University of Carthage, Tunis, Tunisia; General Directorate of Fisheries and Aquaculture, Ministry of Agriculture, Palestine; Department of Ruminant, General Directorate of Extension and Rural Development, Ministry of Agriculture, Palestine; Laboratory of Science and Techniques for Living, Institute of Agricultural and Veterinary Sciences, Mohamed Cherif Messaadia University, Souk Ahras, Algeria (p.131)
  • Journal: African Journal of Agricultural Research 21(2) (2025) 131-138
  • Date: 02/2025
  • Date added: 2026-07-15
  • DOI: 10.5897/AJAR2024.16821
  • Funding: [not reported] — no funding statement anywhere in the paper; Acknowledgements thank Prof. Anthony Kurt Gamperl (Memorial University of Newfoundland) for “comprehensive technical support” only, not funding
  • URL: https://doi.org/10.5897/AJAR2024.16821
  • PDF: Angham et al. - 2025 - Barley (Hordeum vulgare L.) productivity and nutritive value in aquaponic versus hydroponic systems.pdf

Opinion

A small, short (14-day) RCBD comparing barley fodder sprouts grown in one aquaponic tray system against two separate hydroponic controls (plain tap water and tap water + commercial nutrient solution). The design is clean enough (3 treatments x 3 replicate trays x 2 sampling days, GLM with letter-based post-hoc groupings, N=18 stated per row), but the manuscript has several internal arithmetic slips in Table 4 (a dry-matter cell that is off by two orders of magnitude, a crude-protein figure in the Discussion that contradicts the paper’s own table and its own stated average) that are each resolvable by cross-checking against the paper’s own stated column averages — none of them change the paper’s qualitative conclusion (aquaponic barley outperformed both hydroponic arms on fresh weight, dry matter accumulation, and crude protein by day 14). The two hydroponic arms are also never statistically distinguished from each other; the headline comparison throughout is aquaponic vs “the hydroponic treatments” generically. Genuine fish-side data (stocking density, growth, survival) is essentially absent — the tilapia are present but effectively black-boxed as a wastewater source.

Abstract

This study evaluated the effects of aquaponic and hydroponic systems on the germination and growth of barley (Hordeum vulgare L.) in Nablus, West Bank, Palestine. A randomized complete block design with three treatments was employed. Barley seeds were pre-treated through washing, disinfection, and soaking, and germination was conducted in polyethylene trays under three conditions: aquaponic with tilapia, hydroponic with tap water, and hydroponic with a commercial nutrient solution. Growth parameters, including fresh and dry weights of barley sprouts, were measured on days 7 and 14. Water quality parameters, such as total dissolved solids, electrical conductivity, pH, nitrite, nitrate, chlorine, carbonate, total hardness, and temperature, were monitored throughout the study. On day 7, the average fresh weight of barley trays was 7.13 kg, increasing to 10.21 kg by day 14. The aquaponic system exhibited superior performance, achieving a mean fresh weight of 11.80 ± 0.231 kg on day 14, compared to 9.27 ± 0.202 kg and 9.58 ± 0.219 kg in the hydroponic treatments. Additionally, barley grown in the aquaponic system had the highest dry matter net weight (1.963 ± 0.035 kg) and crude protein content (19%) by day 14. These findings highlight the potential of aquaponic systems to enhance barley growth and nutrient content compared to hydroponic systems.

Summary

The authors germinated barley (Hordeum vulgare) fodder in polyethylene trays (90x30 cm, 1 kg seed/tray) in Nablus, West Bank, Palestine, then grew the sprouts for 14 days under three conditions: connected to a 150 L tilapia tank (33 fish, ~100 g each, fed at 1% body weight/day), irrigated with plain tap water, or irrigated with tap water plus 1,400 mL of a defined commercial nutrient solution. Each treatment had three replicate trays, sampled on days 7 and 14 for fresh/dry weight and proximate composition (moisture, ash, crude fibre, crude protein via Kjeldahl x6.25), analysed by GLM (SPSS 22) with a 0.05 significance threshold. By day 14 the aquaponic trays had the highest net fresh weight (11.80 kg vs 9.27 and 9.58 kg), the highest dry-matter net weight (1.963 kg vs 1.320 and 1.263 kg), and the highest crude protein (19% vs 17-18%). Water quality (pH, EC, TDS, nitrate, nitrite, hardness, alkalinity) was tracked across three time windows (Day 1, Days 2-7, Days 8-14) for all three treatments; the nutrient-solution hydroponic arm showed the largest and most volatile swings (e.g. EC and TDS spiking during Days 2-7, pH dropping below 6). The paper argues this supports aquaponics as a nutrient-stable, fodder-enhancing alternative to conventional hydroponic barley production, though it reports no inferential statistics comparing the two hydroponic arms to each other, and provides essentially no fish-growth data of its own.

Experiment data

  • Location: Nablus governorate, West Bank, Palestine (p.132)
  • Design: Randomized complete block design (RCBD), 3 treatments (T1 aquaponic/tilapia, T2 hydroponic/tap water, T3 hydroponic/tap water + nutrient solution) x 3 replicate trays each x 2 sampling days (7, 14); GLM: Yij = mu + Ti + Dj + eij (Eq. 1, p.133)
  • Replicates / n: 3 trays per treatment (“each consisting of three barley trays”, p.132); tables report N=18 (3 treatments x 3 reps x 2 days)
  • Duration: Overall trial window stated as 20 Dec 2023 - 4 Jan 2024 (p.132); barley growth/sampling explicitly on day 7 and day 14 post-introduction to the systems (final/headline results at day 14)
  • Organisms: Barley (Hordeum vulgare) sprouts / Tilapia (Oreochromis niloticus), 33 fish, ~100 g each, in a 150 L tank
  • Statistics: General linear model (GLM), SPSS 22 (IBM, NY, USA); P<0.05 significant, 0.05<P<0.10 trend; means with the same superscript letter (row-wise, N=18) not significantly different
  • Plant fresh weight: Day 14 net tray weight — AP 11.80 +/- 0.231 kg vs HYD-tap 9.27 +/- 0.202 kg vs HYD-nutrient 9.58 +/- 0.219 kg (Table 4)
  • Feed Conversion Rate (FCR): [not reported] — no fish growth/feed-total data given at all

Water quality

This paper: Table 3 gives water-quality figures at Day 1 (shared starting point before the systems diverge) and then separately for each treatment across Days 2-7 and Days 8-14 — three time windows, not a single trial mean. Per SCHEMA.md, ranges (not an average) were recorded for the aquaponic loop’s dedicated trials.csv columns: Aq pH 7.60-7.88; NO3-N 32-50 mg/L; NO2-N 0.28-5.83 mg/L; DO 4.98-7.6 mg/L; EC (converted from the paper’s “ms/cm”, numerically equal to dS/m) 462.33-570.16 dS/m; water temperature 17.16-17.46 degC. TAN/NH4-N was never measured (absent from the parameter list on p.132 and from Table 3). Total Hardness, Total Alkalinity (KH), Carbonate, Chlorine, and TDS have no dedicated trials.csv column and are recorded only in Experimental Remarks (NO COLUMN) below, for all three treatments. The two hydroponic arms’ full pH/DO/EC/temperature/NO2-N/NO3-N ranges are likewise recorded only in Experimental Remarks, since the schema’s water-chemistry columns (Aq pH etc.) represent the aquaponic loop specifically, per the naming convention and prior vault precedent (lenzCommonChicoryProduction2021).

Compared with:

  • todo Ayipio Kim Kim Roh 2019 — lettuce growth in hydroponic vs aquaponic systems, cited (p.135) to support the claim that aquaponics sustains balanced nutrient levels via nutrient recycling
  • todo Ayipio Wells McQuilling Wilson 2019 — meta-analysis of aquaponic vs conventional hydroponic crop yields, cited (p.136) re: aquaponics achieving comparable yields despite lower nutrient concentrations
  • todo Graber Junge 2009 — aquaponic nutrient recycling from fish wastewater, cited (p.136) re: efficient nutrient utilisation and pH stability

Nutritive value

This paper: By day 14, aquaponic barley had the highest dry-matter net weight (1.963 +/- 0.035 kg vs 1.320 and 1.263 kg) and highest crude protein (19% vs 17% and 18% per Table 4 — see WARN-MATERIAL below on the Discussion’s conflicting “21%” figure). Ash content was stable across all treatments/days (~9%). Crude fibre rose from ~17% (day 7) to ~20-22% (day 14), highest in the aquaponic treatment at day 14 (22%).

Compared with:

Linked claims

Citations to chase

  • todo Ayipio, Kim, Kim, Roh (2019) — lettuce hydroponic vs aquaponic growth comparison
  • todo Ayipio, Wells, McQuilling, Wilson (2019) — meta-analysis, aquaponic vs conventional hydroponic crop yields
  • todo Graber, Junge (2009) — aquaponic nutrient recycling from fish wastewater
  • todo Partap, Sharma, HN, Thakur, Verma, Ujala, Bhargava (2023) — microgreens, superfood potential
  • todo Zhang, Xiao, Ager, Kong, Tan (2021) — microgreens nutritional quality and health benefits
  • todo Pinho, David, Garcia, Keesman, Portella, Goddek (2021) — South American fish species suitable for aquaponics
  • todo Lennard, Leonard (2006) — comparison of three hydroponic subsystems in an aquaponic test system

Extraction notes

Type classification: experiment. RCBD with defined treatments (3), replication (3 trays/treatment), two sampling time points, and a stated statistical model (GLM, Eq. 1) with a significance threshold — satisfies SCHEMA.md’s experiment test (controlled manipulation, defined treatments, replication, statistical comparison). Not field-trial (fully controlled tray-based system, not on-farm/production scale) and not exploratory (formally replicated with a hypothesis test, not a descriptive pilot).

Citekey / author metadata discrepancy (flagged, not a WARN tier — a source-metadata issue, not an internal-paper contradiction): Crossref’s record for this DOI (confirmed via https://api.crossref.org/works/10.5897/AJAR2024.16821) has given/family name fields reversed for all four authors — e.g. the corresponding author is recorded with family: "Muayad", given: "Salman", but “Salman” is unambiguously the surname (a single, unambiguous Arabic family name; “Muayad” is unambiguously a given name), and the paper’s own byline lists him as “Muayad Salman3*” (corresponding author) — given-name-first order. zotero-export.csv’s Author field for this record (“Angham, Bani Owdeh; Muayad, Salman; Maria, Chikha; Mohamed, Salah Romdhane”) propagates the same reversed split from the same upstream source. Since the “Muayad Salman” case proves the reversal conclusively, the paper’s own byline order (given name first) was used instead: first author surname = “Bani Owdeh” (not “Angham”), giving citekey baniowdehBarleyHordeumVulgare2025 rather than an angham... key that the auto-generated PDF filename and Crossref/Zotero’s reversed fields would otherwise suggest. Author wikilinks use the same corrected surnames.

Trial-row design choice (judgment call, not a contradiction): The paper has exactly one aquaponic treatment but two independent hydroponic controls (tap water only vs tap water + nutrient solution), each separately tabulated with its own results (Table 3, Table 4) and its own water chemistry. Rather than arbitrarily picking one hydroponic arm as “the” comparator and discarding the other’s data, two trial rows were produced: -T1 (AP paired with HYD-tap) and -T2 (AP paired with HYD-nutrient-solution). The aquaponic-side values (Nwt, DM%, Aq pH/DO/EC/temp/NO2-N/NO3-N ranges) are identical/repeated across both rows by design — see TRIAL DEFINITION in each row’s Experimental Remarks. This mirrors SCHEMA.md’s stated logic in reverse (multiple AP arms vs one repeated HYD control -> multiple rows, same HYD values repeated).

  • ⚠️MATERIAL — Dry matter %, 14-DT3 (hydroponic + nutrient solution, day 14). Table 4 prints this cell as “0.13ᵃ ±1.3”, but the paper’s own stated Day-14 DM average across the three treatments is 14% (p.135, Table 4 “Average” row). (16 + 13 + 0.13)/3 = 9.71, which does not match the stated 14% average; (16 + 13 + 13)/3 = 14 exactly. The printed SD (±1.3) is also implausible for a mean of 0.13 (an order of magnitude larger than the value itself) but is entirely consistent with a mean of 13. Recorded as 13 +/- 1.3, treating “0.13” as a decimal-point typo for “13”, corroborated by the paper’s own independently-stated column average. Affects: Plant dry matter (%) in the -T2 trials.csv row.

  • ⚠️MATERIAL — Crude protein %, 14-DT3 (hydroponic + nutrient solution, day 14). Table 4 gives 14-DT2=17%, 14-DT3=18% (p.135), and the paper’s own stated Day-14 CP average is 18% — (19+17+18)/3 = 18 exactly. However, the Discussion (Nutritive value section, p.136) states: “the Hydroponic treatments on Day 14 (14-DT2 and 14-DT3) recorded lower protein levels of 17 and 21%, respectively” — 21% does not appear anywhere in Table 4, and using it would give (19+17+21)/3 = 19, contradicting the stated 18% average. Table 4’s value (18%) used, treating the Discussion’s “21%” as a transcription error. Affects: crude protein proximate value for HYD-nutrient, day 14, in plant.csv.

  • ⚠️MINOR — Ash % SD, 7-DT3 (hydroponic + nutrient solution, day 7). Table 4 prints “9.3ᵃ ± 8.5”, an SD roughly an order of magnitude larger than every other Ash SD in the table (0.75-0.94 elsewhere) for a comparable mean. Very likely a typo (e.g. for ±0.85), but no single corrected value can be confidently inferred, so recorded exactly as printed (9.3 +/- 8.5) in plant.csv, flagged here for verification. Does not change which mean value is used.

  • Data-quality flag, not a contradiction (EC unit plausibility): Table 3 reports EC in “ms/cm” (milliSiemens/cm), with the hydroponic-nutrient-solution arm reaching 3640 ms/cm during Days 2-7. 1 mS/cm is numerically equal to 1 dS/m, so this would mean an EC roughly 70x that of seawater (~50 dS/m) — physically implausible for a fertigation solution or tap water. The values are far more consistent with the intended unit being µS/cm (i.e. 3.64 dS/m, a normal nutrient-solution EC). Recorded exactly as printed per the prime directive (no inferred unit correction), with the unit label converted only from “ms/cm” to the schema’s “dS/m” (a straight relabelling, since the two are the numerically identical unit — see UNIT CONVERSION ONLY below). Flagged for the user to verify against the original lab instrument/units before using in any unit-sensitive downstream analysis.

  • [not reported]: Initial fish stock density (kg/m3) — 33 tilapia x ~100 g in a 150 L tank would require dividing stated quantities, which is derivation; paper gives no density figure directly. FCR, SGR, fish size final, fish biomass created, fish survival rate, fish weight gain, fish trial duration (days), total feed (kg), water recycle (L/min), daily water exchange rate — none stated; the fish component is described only as a feed source (1% body weight/day of a named commercial diet), never tracked for growth or survival. Feed N and K (Table 1 gives only Protein 35%, Phosphorus 1.2% for the fish feed — no nitrogen or potassium % given). Tissue nitrate (AP or HYD) — the paper measures moisture/DM/ash/crude fibre/crude protein, never tissue nitrate specifically. Plant height, leaf count, SPAD, Plants/m2 — not measured (this is a fodder-sprout tray system, not individually counted/measured plants). Lat/Long — only “Nablus governorate, West Bank, Palestine” given, no coordinates anywhere in the paper. Average room temperature — germination/growth explicitly run “without any adjustments to temperature, light, or humidity” (p.132) but no ambient temperature number is given. Water type/classification, System type, Fish Category, Plant Category — the paper does not use categorising terms for any of these beyond the treatment descriptions themselves (aquaponic/hydroponic, tap water, nutrient solution).

  • [unclear]: Whether “Biological system already in use” applies to the fish tank (i.e. whether the tilapia tank had an already-cycled biofilter before the 14-day barley trial began) — not stated either way, recorded NR rather than guessing.

  • NO COLUMN (trials.csv has no field for these): Total Hardness (TH, mg/L, Table 3): D1=225 (shared); AP D2-7=125, D8-14=235; HYD-tap D2-7=112.5, D8-14=150; HYD-nutrient D2-7=225, D8-14=257. Total Alkalinity (KH, mg/L): D1=140; AP D2-7=200, D8-14=202; HYD-tap D2-7=120, D8-14=120; HYD-nutrient D2-7=60, D8-14=0. Carbonate (mg/L): D1=18.66; AP D2-7=150, D8-14=108.57; HYD-tap D2-7=140, D8-14=108.57; HYD-nutrient D2-7=15.33, D8-14=0. Chlorine Cl2 (mg/L): D1=0.15; all treatments D2-7 approx 0.016; all D8-14 = 0. TDS (PPM): D1=285.33; AP D2-7=303.5, D8-14=258.42; HYD-tap D2-7=314, D8-14=250; HYD-nutrient D2-7=1715, D8-14=1019.28. Hydroponic-side water chemistry for the schema’s AP-only columns (since Aq pH etc. represent the aquaponic loop, per convention): HYD-tap (T2) pH range 7.54-7.88, DO range 6.98-7.6 mg/L, EC range 462.33-756.33 dS/m (as printed, see EC flag above), water temp range 17.27-17.46 degC, NO2-N range 1.66-4.83 mg/L, NO3-N range 30-50 mg/L. HYD-nutrient (T3) pH range 5.62-7.88, DO range 6.21-7.6 mg/L, EC range 462.33-3640 dS/m (as printed, see EC flag above), water temp range 17.13-17.46 degC, NO2-N range 1.66-22.5 mg/L, NO3-N range 50-203 mg/L. Tray-level totals not fitting per-plant/per-area columns: Day 7 net weight (Nwt) AP=7.94+/-0.173, HYD-tap=6.82+/-0.144, HYD-nutrient=6.63+/-0.115 kg/tray; Day 14 Nwt AP=11.80+/-0.231 (used as the AP/HYD generic yield placeholder columns), HYD-tap=9.27+/-0.202, HYD-nutrient=9.58+/-0.219 kg/tray. Dry-matter net weight (DMNwt, kg/tray): Day 7 AP=0.99+/-0.029, HYD-tap=0.773+/-0.025, HYD-nutrient=0.756+/-0.02; Day 14 AP=1.963+/-0.035, HYD-tap=1.320+/-0.03, HYD-nutrient=1.263+/-0.028. Total protein per tray (CPNwt, g): Day 7 AP=163.31+/-2.88, HYD-tap=134.83+/-2.5, HYD-nutrient=101.65+/-2.3; Day 14 AP=387.44+/-3.5, HYD-tap=227.18+/-2.8, HYD-nutrient=232.15+/-2.90 (uses the corrected 18% CP figure, see WARN-MATERIAL above).

  • UNIT CONVERSION ONLY: EC values relabelled from the paper’s “ms/cm” to trials.csv’s expected “dS/m” — the two units are numerically identical (1 mS/cm = 1 dS/m), so no value was changed, only the unit label (see the EC plausibility flag above for the separate magnitude concern).

  • plant.csv note: Moisture (H2O %), Ash (%), Crude Fibre (%), and Crude Protein (%) — all proximate-category plant analytes per SCHEMA.md — are recorded in plant.csv, not trials.csv, since trials.csv’s only matching column is Plant dry matter (%). Both day 7 and day 14 values are included as separate rows (long format), one row per analyte per system per day.

Source: Angham et al. - 2025 - Barley (Hordeum vulgare L.) productivity and nutritive value in aquaponic versus hydroponic systems.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

baniowdehBarleyHordeumVulgare2025-T1

Fish

FieldValue
FishNile tilapia (Oreochromis niloticus)
Protein35
P1.2
% of body weight1
Fish size initial100 (stated as ‘approximately’, p.132)
Feed regimeCommercial diet from a local feed mill, fed at 1% of body weight daily (composition in Table 1: protein 35%, fat 6%, wet 10%, cellulose 5%, ash 8%, calcium 17%, phosphorus 1.2%, salt 0.7%)

Water

FieldValue
Water volume in the system150 (fish tank only; total system volume including trays not stated, p.132)
Aq pH7.60-7.88 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
Dissolved Oxigen4.98-7.6 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
EC462.33-570.16 (range across D1/D2-7/D8-14, no trial mean reported, Table 3; UNIT CONVERSION ONLY: ms/cm as printed relabelled dS/m, numerically identical)
Water temperature17.16-17.46 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
NO2-N0.28-5.83 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
NO3-N32-50 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)

Plant

FieldValue
PlantBarley (Hordeum vulgare L.)
DetailsHarvested at day 14 (final/headline result); day 7 interim net weight and proximate values recorded in Experimental Remarks (NO COLUMN).
Days Plant after transplant14
Plant dry matter16 +/- 1.5 (AP, day14; HYD-tap this row = 13 +/- 1.2, Table 4)

System & Setup

FieldValue
System typePolyethylene germination trays connected to a 150 L tilapia tank (recirculating), no substrate/media (p.132)
Iron supplementedN (Tap water only (T2); no iron or other supplementation stated for this arm (p.132))
Climate controlN (“Germination process was carried out without any adjustments to temperature, light, or humidity” (p.132))
Artificial LightingN (Same statement as Climate control — no adjustments to light (p.132))
Nutrient supplementedN (Aquaponic arm receives nutrients solely from fish waste; T2 hydroponic arm is plain tap water with no supplementation (p.132))
Equipment150 L fish tank; polyethylene germination trays (90x30 cm); Protherm PFL 110/10 forced-air oven and muffle furnace; Kjeldahl nitrogen apparatus; NDF/ADF fibre analysis apparatus (Van Soest et al. 1991 method); SPSS 22
Control ParametersRCBD, 3 treatments x 3 replicates x 2 sampling days (7, 14); GLM Yij = mu + Ti + Dj + eij; P<0.05 significant, 0.05<P<0.10 trend (p.133)
CombinationTilapia (Oreochromis niloticus) aquaponic wastewater vs. hydroponic tap water vs. hydroponic tap water + commercial nutrient solution, for barley (Hordeum vulgare) fodder-sprout production over 14 days

Site

FieldValue
RegionMiddle East
CountryPalestine (West Bank)

Results & Statistics

FieldValue
Measured Unitkg net fresh/dry weight per tray (90x30 cm tray, 1 kg seed sown); % (moisture, ash, crude fibre, crude protein) — see plant.csv for proximate analytes
Statistic DetailsGeneral linear model (GLM), completely randomized model, 3 treatments x 3 replicates x 2 sampling days (7,14); Yij = mu + Ti + Dj + eij; SPSS 22 (IBM, NY, USA); P<0.05 significant, trend at 0.05<P<0.10 (p.133)
Statistically analysedY
Replicates (n)3
AP11.80 +/- 0.231
HYD9.27 +/- 0.202

Experimental Remarks: TRIAL DEFINITION: -T1 = the single aquaponic treatment (tilapia, T1 in the paper) paired with the hydroponic tap-water control (T2 in the paper). This paper has one aquaponic arm but two independent hydroponic controls (tap water only, and tap water + nutrient solution), each separately tabulated (Tables 3-4). To avoid discarding either hydroponic dataset, two trial rows were produced (-T1, -T2); the aquaponic-side values are identical/repeated across both rows by design — see -T2’s remarks for the paired-nutrient-solution comparison. WARN-MATERIAL Plant dry matter %, 14-DT3 (HYD-nutrient, day14): Table 4 prints ‘0.13a +/-1.3’, but the paper’s own stated Day-14 DM average (14%) only reconciles as (16+13+13)/3=14, not (16+13+0.13)/3=9.71. SD (+/-1.3) is also implausible for a mean of 0.13 but fits a mean of 13. Recorded 13 +/-1.3, treating ‘0.13’ as a decimal-point typo for ‘13’. WARN-MATERIAL Crude protein %, 14-DT3 (HYD-nutrient, day14): Table 4 gives 17% (14-DT2) and 18% (14-DT3), matching the paper’s own stated Day-14 CP average of 18% exactly ((19+17+18)/3=18). Discussion text (p.136) instead states ‘lower protein levels of 17 and 21%, respectively’ — 21% appears nowhere in Table 4 and would break the stated average ((19+17+21)/3=19). Table 4’s 18% used; Discussion’s 21% treated as a transcription error. WARN-MINOR Ash % SD, 7-DT3 (HYD-nutrient, day7): Table 4 prints ‘9.3a +/-8.5’, an SD an order of magnitude larger than every other Ash SD in the table (0.75-0.94); very likely a typo (e.g. for +/-0.85). Recorded exactly as printed; does not change which mean is used. NO COLUMN: Total Hardness (TH, mg/L, Table 3): D1=225 (shared); AP D2-7=125, D8-14=235; HYD-tap D2-7=112.5, D8-14=150; HYD-nutrient D2-7=225, D8-14=257. Total Alkalinity (KH, mg/L): D1=140; AP D2-7=200, D8-14=202; HYD-tap D2-7=120, D8-14=120; HYD-nutrient D2-7=60, D8-14=0. Carbonate (mg/L): D1=18.66; AP D2-7=150, D8-14=108.57; HYD-tap D2-7=140, D8-14=108.57; HYD-nutrient D2-7=15.33, D8-14=0. Chlorine Cl2 (mg/L): D1=0.15; all treatments D2-7 approx 0.016; all D8-14=0. TDS (PPM): D1=285.33; AP D2-7=303.5, D8-14=258.42; HYD-tap D2-7=314, D8-14=250; HYD-nutrient D2-7=1715, D8-14=1019.28. Tray-level totals: Day7 Nwt AP=7.94+/-0.173, HYD-tap=6.82+/-0.144, HYD-nutrient=6.63+/-0.115 kg/tray; Day14 Nwt AP=11.80+/-0.231 (used as AP/HYD placeholder columns), HYD-tap=9.27+/-0.202, HYD-nutrient=9.58+/-0.219 kg/tray. DMNwt (kg/tray): Day7 AP=0.99+/-0.029, HYD-tap=0.773+/-0.025, HYD-nutrient=0.756+/-0.02; Day14 AP=1.963+/-0.035, HYD-tap=1.320+/-0.03, HYD-nutrient=1.263+/-0.028. CPNwt (total protein/tray, g): Day7 AP=163.31+/-2.88, HYD-tap=134.83+/-2.5, HYD-nutrient=101.65+/-2.3; Day14 AP=387.44+/-3.5, HYD-tap=227.18+/-2.8, HYD-nutrient=232.15+/-2.90 (uses corrected 18% CP, see WARN-MATERIAL). UNIT CONVERSION ONLY: EC relabelled from paper’s ‘ms/cm’ to schema’s ‘dS/m’ — numerically identical units (1 mS/cm = 1 dS/m), no value changed. EC MAGNITUDE FLAG: printed EC values (up to 3640 for T3 D2-7) are physically implausible at face value (~70x seawater); far more consistent with the intended unit being uS/cm (i.e. 3.64 dS/m); recorded exactly as printed per prime directive, not corrected. NO COLUMN (HYD-tap, T2, water chemistry — schema’s Aq* columns represent the aquaponic loop only): pH range 7.54-7.88; DO range 6.98-7.6 mg/L; EC range 462.33-756.33 dS/m (as printed, ms/cm relabelled, see EC magnitude flag); water temp range 17.27-17.46 degC; NO2-N range 1.66-4.83 mg/L; NO3-N range 30-50 mg/L (all Table 3).

baniowdehBarleyHordeumVulgare2025-T2

Fish

FieldValue
FishNile tilapia (Oreochromis niloticus)
Protein35
P1.2
% of body weight1
Fish size initial100 (stated as ‘approximately’, p.132)
Feed regimeCommercial diet from a local feed mill, fed at 1% of body weight daily (composition in Table 1: protein 35%, fat 6%, wet 10%, cellulose 5%, ash 8%, calcium 17%, phosphorus 1.2%, salt 0.7%)

Water

FieldValue
Water volume in the system150 (fish tank only; total system volume including trays not stated, p.132)
Aq pH7.60-7.88 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
Dissolved Oxigen4.98-7.6 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
EC462.33-570.16 (range across D1/D2-7/D8-14, no trial mean reported, Table 3; UNIT CONVERSION ONLY: ms/cm as printed relabelled dS/m, numerically identical)
Water temperature17.16-17.46 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
NO2-N0.28-5.83 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)
NO3-N32-50 (range across D1/D2-7/D8-14, no trial mean reported, Table 3)

Plant

FieldValue
PlantBarley (Hordeum vulgare L.)
DetailsHarvested at day 14 (final/headline result); day 7 interim net weight and proximate values recorded in Experimental Remarks (NO COLUMN).
Days Plant after transplant14
Plant dry matter16 +/- 1.5 (AP, day14; HYD-nutrient this row = 13 +/- 1.3 [corrected from printed 0.13, see WARN-MATERIAL], Table 4)

System & Setup

FieldValue
System typePolyethylene germination trays connected to a 150 L tilapia tank (recirculating), no substrate/media (p.132)
Iron supplementedY (Nutrient solution (Table 2) includes chelated iron at 2.5 mg/L for the T3 hydroponic arm; aquaponic arm receives no separate iron supplement)
Climate controlN (“Germination process was carried out without any adjustments to temperature, light, or humidity” (p.132))
Artificial LightingN (Same statement as Climate control — no adjustments to light (p.132))
Nutrient supplementedY (T3 hydroponic arm: 1,400 mL of a defined nutrient solution added to tap water (Table 2: N 180, P 60, K 250, Ca 120, Mg 40, S 25 mg/L macronutrients; Fe 2.5, Mn 0.75, Zn 0.75, Cu 0.25, B 0.75, Mo 0.075 mg/L micronutrients))
Equipment150 L fish tank; polyethylene germination trays (90x30 cm); Protherm PFL 110/10 forced-air oven and muffle furnace; Kjeldahl nitrogen apparatus; NDF/ADF fibre analysis apparatus (Van Soest et al. 1991 method); SPSS 22
Control ParametersRCBD, 3 treatments x 3 replicates x 2 sampling days (7, 14); GLM Yij = mu + Ti + Dj + eij; P<0.05 significant, 0.05<P<0.10 trend (p.133)
CombinationTilapia (Oreochromis niloticus) aquaponic wastewater vs. hydroponic tap water vs. hydroponic tap water + commercial nutrient solution, for barley (Hordeum vulgare) fodder-sprout production over 14 days

Site

FieldValue
RegionMiddle East
CountryPalestine (West Bank)

Results & Statistics

FieldValue
Measured Unitkg net fresh/dry weight per tray (90x30 cm tray, 1 kg seed sown); % (moisture, ash, crude fibre, crude protein) — see plant.csv for proximate analytes
Statistic DetailsGeneral linear model (GLM), completely randomized model, 3 treatments x 3 replicates x 2 sampling days (7,14); Yij = mu + Ti + Dj + eij; SPSS 22 (IBM, NY, USA); P<0.05 significant, trend at 0.05<P<0.10 (p.133)
Statistically analysedY
Replicates (n)3
AP11.80 +/- 0.231
HYD9.58 +/- 0.219

Experimental Remarks: TRIAL DEFINITION: -T2 = the same single aquaponic treatment (tilapia, T1 in the paper) paired instead with the hydroponic + nutrient-solution control (T3 in the paper). Aquaponic-side values are identical/repeated from -T1 by design — see -T1’s remarks for the paired-tap-water comparison and the full judgment-call explanation. WARN-MATERIAL Plant dry matter %, 14-DT3 (HYD-nutrient, day14): Table 4 prints ‘0.13a +/-1.3’, but the paper’s own stated Day-14 DM average (14%) only reconciles as (16+13+13)/3=14, not (16+13+0.13)/3=9.71. SD (+/-1.3) is also implausible for a mean of 0.13 but fits a mean of 13. Recorded 13 +/-1.3, treating ‘0.13’ as a decimal-point typo for ‘13’. WARN-MATERIAL Crude protein %, 14-DT3 (HYD-nutrient, day14): Table 4 gives 17% (14-DT2) and 18% (14-DT3), matching the paper’s own stated Day-14 CP average of 18% exactly ((19+17+18)/3=18). Discussion text (p.136) instead states ‘lower protein levels of 17 and 21%, respectively’ — 21% appears nowhere in Table 4 and would break the stated average ((19+17+21)/3=19). Table 4’s 18% used; Discussion’s 21% treated as a transcription error. WARN-MINOR Ash % SD, 7-DT3 (HYD-nutrient, day7): Table 4 prints ‘9.3a +/-8.5’, an SD an order of magnitude larger than every other Ash SD in the table (0.75-0.94); very likely a typo (e.g. for +/-0.85). Recorded exactly as printed; does not change which mean is used. NO COLUMN: Total Hardness (TH, mg/L, Table 3): D1=225 (shared); AP D2-7=125, D8-14=235; HYD-tap D2-7=112.5, D8-14=150; HYD-nutrient D2-7=225, D8-14=257. Total Alkalinity (KH, mg/L): D1=140; AP D2-7=200, D8-14=202; HYD-tap D2-7=120, D8-14=120; HYD-nutrient D2-7=60, D8-14=0. Carbonate (mg/L): D1=18.66; AP D2-7=150, D8-14=108.57; HYD-tap D2-7=140, D8-14=108.57; HYD-nutrient D2-7=15.33, D8-14=0. Chlorine Cl2 (mg/L): D1=0.15; all treatments D2-7 approx 0.016; all D8-14=0. TDS (PPM): D1=285.33; AP D2-7=303.5, D8-14=258.42; HYD-tap D2-7=314, D8-14=250; HYD-nutrient D2-7=1715, D8-14=1019.28. Tray-level totals: Day7 Nwt AP=7.94+/-0.173, HYD-tap=6.82+/-0.144, HYD-nutrient=6.63+/-0.115 kg/tray; Day14 Nwt AP=11.80+/-0.231 (used as AP/HYD placeholder columns), HYD-tap=9.27+/-0.202, HYD-nutrient=9.58+/-0.219 kg/tray. DMNwt (kg/tray): Day7 AP=0.99+/-0.029, HYD-tap=0.773+/-0.025, HYD-nutrient=0.756+/-0.02; Day14 AP=1.963+/-0.035, HYD-tap=1.320+/-0.03, HYD-nutrient=1.263+/-0.028. CPNwt (total protein/tray, g): Day7 AP=163.31+/-2.88, HYD-tap=134.83+/-2.5, HYD-nutrient=101.65+/-2.3; Day14 AP=387.44+/-3.5, HYD-tap=227.18+/-2.8, HYD-nutrient=232.15+/-2.90 (uses corrected 18% CP, see WARN-MATERIAL). UNIT CONVERSION ONLY: EC relabelled from paper’s ‘ms/cm’ to schema’s ‘dS/m’ — numerically identical units (1 mS/cm = 1 dS/m), no value changed. EC MAGNITUDE FLAG: printed EC values (up to 3640 for T3 D2-7) are physically implausible at face value (~70x seawater); far more consistent with the intended unit being uS/cm (i.e. 3.64 dS/m); recorded exactly as printed per prime directive, not corrected. NO COLUMN (HYD-nutrient, T3, water chemistry — schema’s Aq* columns represent the aquaponic loop only): pH range 5.62-7.88; DO range 6.21-7.6 mg/L; EC range 462.33-3640 dS/m (as printed, ms/cm relabelled, see EC magnitude flag); water temp range 17.13-17.46 degC; NO2-N range 1.66-22.5 mg/L; NO3-N range 50-203 mg/L (all Table 3).

Plant Measurements

TrialSystemCategoryAnalyteValueUnitSig.Location
baniowdehBarleyHordeumVulgare2025-T1APproximateMoisture (H2O) (day 7)87 ± 1.7%abTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateMoisture (H2O) (day 7)88 ± 2.2%bTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateAsh (day 7)9.1 ± 0.86%aTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateAsh (day 7)9.3 ± 0.94%aTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateCrude fibre (day 7)17 ± 2.8%aTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateCrude fibre (day 7)17 ± 2.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateCrude protein (day 7)16 ± 2.8%bTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateCrude protein (day 7)17 ± 3.7%bcTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateMoisture (H2O) (day 14)84 ± 2.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateMoisture (H2O) (day 14)86 ± 1.8%abTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateAsh (day 14)9 ± 0.82%aTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateAsh (day 14)9.2 ± 0.75%aTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateCrude fibre (day 14)22 ± 3.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateCrude fibre (day 14)17 ± 2.8%aTable 4
baniowdehBarleyHordeumVulgare2025-T1APproximateCrude protein (day 14)19 ± 4.3%cTable 4
baniowdehBarleyHordeumVulgare2025-T1HYD-tapproximateCrude protein (day 14)17 ± 2.9%bTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateMoisture (H2O) (day 7)87 ± 1.7%abTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateMoisture (H2O) (day 7)88 ± 1.5%bTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateAsh (day 7)9.1 ± 0.86%aTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateAsh (day 7)9.3 ± 8.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateCrude fibre (day 7)17 ± 2.8%aTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateCrude fibre (day 7)18 ± 3%aTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateCrude protein (day 7)16 ± 2.8%bTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateCrude protein (day 7)13 ± 2.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateMoisture (H2O) (day 14)84 ± 2.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateMoisture (H2O) (day 14)86 ± 2.2%abTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateAsh (day 14)9 ± 0.82%aTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateAsh (day 14)8.9 ± 0.78%aTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateCrude fibre (day 14)22 ± 3.5%aTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateCrude fibre (day 14)21 ± 3.2%aTable 4
baniowdehBarleyHordeumVulgare2025-T2APproximateCrude protein (day 14)19 ± 4.3%cTable 4
baniowdehBarleyHordeumVulgare2025-T2HYD-nutrientproximateCrude protein (day 14)18 ± 3.1%bcTable 4

Graph View

Backlinks