Partially treated domestic wastewater as a nutrient source for tomatoes (Lycopersicum solanum) grown in a hydroponic system: effect on nutrient absorption and yield
Metadata
- Cite key: magwazaPartiallyTreatedDomestic2020
- Item type: Journal Article
- Authors: S.T. Magwaza, L.S. Magwaza, A.O. Odindo, A. Mditshwa, C. Buckley
- Affiliation: Discipline of Horticultural Science / Discipline of Crop Science, School of Agricultural, Earth and Environmental Science, University of KwaZulu-Natal, Pietermaritzburg, South Africa; Pollution Research Group, Faculty of Engineering, University of KwaZulu-Natal, Howard College, Durban, South Africa; Department of Agriculture, University of Zululand, KwaDlangezwa, South Africa
- Journal: Heliyon 6 (2020) e05745
- Date: 12/2020
- Date added: [not reported]
- DOI: 10.1016/j.heliyon.2020.e05745
- Funding: University of KwaZulu-Natal (UKZN), College of Agriculture, Engineering and Sciences; National Research Foundation (NRF) of South Africa
- URL: https://doi.org/10.1016/j.heliyon.2020.e05745
- PDF:
Magwaza et al. - 2020 - Partially treated domestic wastewater as a nutrien.pdf
Opinion
A clean, well-replicated CRD comparing three nutrient sources with proper ANOVA/LSD testing, but the two most decision-relevant outcomes (fruit yield, biomass) are reported only as bar charts with no printed numbers in text or tables, which limits how far this paper’s headline claims can be re-used quantitatively. Not an aquaponics paper at all — no fish, no aquaculture, no biofilter loop. It studies domestic (human) wastewater as a hydroponic nutrient source, cited here only because it appears in the aquaponics-adjacent literature (DEWATS/wastewater-hydroponics) and is referenced by companion papers from the same group that do touch aquaponics comparisons (Roosta and Hamidpour, 2011, cited but not this paper’s own data).
Abstract
Using effluent from the anaerobic baffled reactor (ABR) of the decentralised wastewater treatment system (DEWATS) as a sole nutrient source is not sufficient for tomato plants grown in hydroponic system. The study investigated the effects of commercial hydroponic fertilizer mix (CHFM) combined with ABR effluent on tomato growth and yield. A media-based hydroponic technique consisting of three treatments, namely, ABR effluent, CHFM, and ABR effluent combined with CHFM (ABR + CHFM (50:50 v/v) was used. The results showed that plant growth parameters, biomass, fruit yield and shoot nutrient content were significantly higher in tomato plants fed with CHFM and ABR + CHFM than those grown in ABR effluent. Addition of 50 % dose of CHFM in ABR wastewater (ABR + CHFM) increased shoot N, K, Ca and Zn. These results indicated that adding 50% CHFM can alleviate nutrient deficiencies when partially treated wastewater from anaerobic digester is used as a nutrient source for hydroponic tomato cultivation.
Summary
The authors grew tomato (‘Monica’, determinate) in three parallel media-based hydroponic systems (pots with pine-shaving substrate, drip-fed from a recirculating 100 L nutrient tank) at Newlands Mashu Research Station, Durban, South Africa, from March-June 2019. Three nutrient sources were compared in a complete randomised design with 3 replicates: raw anaerobic-baffled-reactor (ABR) domestic wastewater effluent, a commercial hydroponic fertilizer mix (CHFM, the control), and a 50:50 mix of the two (ABR+CHFM). Plant height, leaf area index, stem diameter, chlorophyll index and photosynthetic rate were tracked at seedling/vegetative/harvest stages (Table 2); shoot macro/micronutrient concentrations were measured destructively at 106 days after transplanting (Table 3); shoot fresh/dry weight, total biomass, fruit yield, fruit number and fruit mass were reported only as bar charts (Figure 2), with no numeric values given in text or tables. ABR-effluent-only plants consistently underperformed CHFM and ABR+CHFM on growth, biomass and yield indicators, attributed to low N, P, K and Ca in the wastewater; ABR+CHFM plants statistically matched CHFM on most outcomes while also showing elevated shoot Zn, Fe, Mn and Cu, indicating that a 50% fertilizer top-up can compensate for the wastewater’s macronutrient deficit. This is a pure wastewater-fertigation hydroponics study; there is no fish, aquaculture, or biofiltration component anywhere in the design.
Experiment data
- Location: Newlands Mashu Research Station, Durban, South Africa (polyethylene tunnel)
- Design: Complete randomised design (CRD), 3 nutrient-source treatments x 3 replicates; media-based hydroponic pots (pine shavings substrate)
- Replicates / n: 3 (stated experimental replicates); growth-parameter table (Table 2) pooled n=15; nutrient-solution chemistry (Table 1) pooled n=9
- Duration: Transplant to 106 days after transplanting (fruit harvested weekly from 72-106 DAT)
- Organisms: Tomato (Solanum lycopersicum) cv. ‘Monica’ (determinate) — no fish/aquaculture organism
- Statistics: One-way ANOVA, Fischer’s LSD (5%), Genstat v.18
- Plant height: ABR effluents 50.33ᵃ / ABR+CHFM 58.80ᶜ / CHFM 55.27ᵇ cm plant⁻¹ at harvest stage (106 DAT) (Table 2)
- Shoot nitrogen content: ABR effluents 28.8ᵃ / ABR+CHFM 34.8ᵇ / CHFM 38.2ᶜ mg/g (Table 3)
Nutrient solution chemistry (Table 1)
This paper: ABR effluent was consistently low in Nitrate-N (0.74±0.08 mg/L) and Total P (5.46±0.73 mg/L) relative to CHFM (63.4±1.10 and 9.47±0.76 mg/L) and ABR+CHFM (27.6±1.84 and 13.4±1.90 mg/L), but high in several micronutrients (Fe 135.0±14.00 mg/L vs CHFM’s 100±8.06; Mn 41.0±2.67 vs 42.0±1.46 similar). EC was lowest in ABR effluent (799±15.56) vs CHFM (1531±13.44) and ABR+CHFM (1532±14.14); pH ABR+CHFM 7.77±0.04 vs CHFM 6.93±0.05 vs ABR effluent 7.86±0.16.
Compared with:
- #todo Khan et al. 2011 — wastewater + CHFM did not raise leaf heavy-metal levels in field tomatoes; also gives the 150 mg/kg permissible shoot-Fe limit cited here.
- #todo Roosta and Hamidpour 2011 — foliar K/micronutrient application increased tomato growth in aquaponics and hydroponics; the paper’s only aquaponics reference, cited for comparison, not this paper’s own data.
- #todo Dysko et al. 2009 — reported a 13% yield/tissue-P reduction when nutrient solution pH rose 5.5->6.5, contrasting with this paper’s own pH-P discussion (p.6).
Plant growth (Table 2, Figure 2)
This paper: Plant height, LAI showed significant (P<0.05) treatment differences at all three growth stages; ABR+CHFM was tallest at harvest (58.80 cm) vs CHFM (55.27 cm) and ABR effluents (50.33 cm, shortest). Stem diameter was never significantly different among treatments. Shoot fresh/dry weight, total biomass, fruit yield, fruit number and fruit mass (Figure 2 a-f) were all significantly (P<0.001) lowest in ABR-effluent-fed plants and statistically similar between ABR+CHFM and CHFM — but Figure 2 gives bar charts only (with P-value and LSD per panel), no printed numeric values in text or table, so none of these six outcomes could be extracted as point values (see Extraction notes).
Compared with: none cited directly for these specific figures.
Shoot mineral nutrition (Table 3)
This paper: ABR-effluent plants had significantly lower shoot N, P, K, Ca (28.8 mg/g, 4.3 mg/g, 9.1 mg/g, 24.8 mg/g respectively) than ABR+CHFM and CHFM, but significantly higher Mg (9.3 vs 8.1 and 6.9 mg/g) and higher Fe, Cu, Mn (216 mg/kg Fe, 945.5 mg/kg Cu, 217.0 mg/kg Mn) than the other two treatments — except Zn, which was lowest in ABR effluent (44 mg/kg vs 81 and 70 mg/kg). Shoot Fe exceeded the 150 mg/kg permissible limit (Khan et al., 2011) in all three treatments, including CHFM.
Compared with:
- #todo Hisamitsu et al. 2001 — zinc/iron as structural components of chlorophyll-synthesis proteins/enzymes, cited to explain the higher chlorophyll content of micronutrient-rich wastewater-fed plants.
Citations to chase
- #todo Khan et al. (2011) — wastewater + CHFM did not raise leaf heavy-metal levels; source of the 150 mg/kg permissible shoot-Fe limit
- #todo Roosta and Hamidpour (2011) — this paper’s only cited aquaponics study (foliar K/micronutrients on tomato in aquaponics vs hydroponics)
- #todo Dysko et al. (2009) — pH 5.5->6.5 caused 13% yield/tissue-P reduction in soilless tomato
- #todo Liu et al. (2011) — P + Fe supplementation increased lettuce shoot biomass in biogas-slurry hydroponics
- #todo Magwaza et al. (2020b, 2020c) — companion papers from the same trial/group (Agric. Water Manag. 234), Part I (photosynthesis/leaf gas exchange/tissue minerals) and Part II (growth and yield) — likely report overlapping or complementary data on the same system, not separately extracted here
Extraction notes
No aquaponic/aquaculture component whatsoever. This is a pure wastewater-fertigation hydroponics study: three media-based hydroponic units, no fish, no biofilter, no recirculating aquaponic loop of any kind. It is included in this vault only as wastewater-hydroponics literature adjacent to aquaponics (DEWATS reuse), and its only mention of aquaponics is a single citation to Roosta and Hamidpour (2011) for foliar nutrient effects, not its own data. Fish block in trials.csv is entirely NA. Aq pH is also NA for both trial rows — the schema defines it as “aquaponic loop” pH and this paper has no aquaponic loop at all (unlike a bioponic system with a biofilter sump, there is no biofiltration or fish-tank compartment here to anchor that column); the paper’s own nutrient-solution pH/EC/DO/BOD/COD/TSS/elemental panel (Table 1) is recorded in Experimental Remarks as NO COLUMN data instead.
⚠️WARN-MINOR EC/pH unit header mismatch: Table 1’s column header reads “Parameter (mg/l)” applied uniformly to all 18 rows, including EC, pH, DO — units that cannot physically be mg/L. This is very likely a table-formatting shortcut (the header only genuinely applies to the ionic/nutrient rows) rather than a real measurement error, and it does not create a value conflict (no second value exists to compare against). No cell is affected because EC/pH have no direct schema-consistent home in this NA-block paper (see below) — noted for the record only.
⚠️WARN-MINOR Table 3 Na column: no significance letters are printed for Na at all, despite the table’s own P-value row stating P=0.001 for Na (matching the significance level of every other analyte, all of which do carry letters). LSD given for Na is 0.069 — implausibly small given Na means range from 2496.8 to 7371.7, an inconsistency between the claimed LSD and the (absent) letter grouping. This does not affect the recorded means themselves (directly printed, unambiguous) — only the Significance field for Na is left NR in plant.csv rather than fabricating a letter grouping. No downstream effect on quality score (MINOR, per SCHEMA.md, “does not affect any extracted cell”).
[not reported] / [unclear] fields, grouped:
- Yield/biomass point values [not reported]: shoot fresh weight, shoot dry weight, total biomass, fruit yield, fruit number, fruit mass — all Figure 2 bar charts only, no printed numeric value in text or table for any treatment. Per “never read values off a figure,” left NR in both trials.csv (
Plant fresh weight,Plant dry matter,AP,HYD) and plant.csv is not applicable (these are growth/yield metrics, not one of the four plant.csv analyte categories). - Water temperature [not reported]: no nutrient-solution temperature given (only tunnel air min/max 13-34°C, recorded as room temperature range, not a trial mean).
- NO2-N [not reported]: Table 1 measures Ammonium-N and Nitrate-N but not nitrite specifically.
- Water recycle (L/min) [not reported]: pump is named (“submersible pump”) but no flow rate stated.
- Plants/m2 [not reported]: bed dimensions (15 x 0.5 x 0.9 m) given but plant count/spacing never stated — computing density would be derivation.
- Daily Water exchange rate [not reported as a %]: nutrient solutions were replaced every 2 weeks (early stage) then weekly (mature stage) — a replacement schedule, not a stated fractional daily exchange rate; recorded as NR with the schedule noted in remarks.
- Plant Category [unclear]: the paper’s Introduction classes tomato as a “fruit crop” only when generically describing prior wastewater-hydroponic literature (p.1), not as a self-applied category for its own cultivar — left NR per the “paper does not categorise” convention.
- Lat/Long [not reported]: only “Newlands Mashu Research Station, Durban” named, no coordinates given.
NO COLUMN items (Table 1 nutrient-solution panel, no dedicated trials.csv columns beyond NH4-N/NO3-N): Total phosphorus, Potassium, Calcium, Magnesium, Sulphur, Iron, Manganese, Sodium, Copper, Zinc, BOD, COD, TSS, EC, and pH for all three nutrient sources (ABR effluent / CHFM / ABR+CHFM) — full values recorded per-trial in Experimental Remarks, prefixed NO COLUMN, since this rich water-chemistry panel would otherwise be discarded. This is flagged in the batch report as a water panel excluded from a dedicated slot.
Not a taxonomic contradiction, just noted: the paper’s own title and running text use “Lycopersicum solanum” for tomato; the standard accepted binomial is Solanum lycopersicum. Recorded as printed by the paper (not corrected), since CLAUDE.md’s prime directive is to transcribe the paper’s own terms, not to silently fix them.
Source: Magwaza et al. - 2020 - Partially treated domestic wastewater as a nutrien.pdf
Data Tables
Structured data extracted from this paper into the vault's
trials.csv/plant_measurements.csvdatasets. Fields the paper didn't report are omitted. Download the full datasets (measurements).
Trial Parameters
magwazaPartiallyTreatedDomestic2020-T1
Water
| Field | Value |
|---|---|
| Water volume in the system | 100 L (nutrient solution tank capacity per hydroponic unit, p.2; growth-bed liquid volume not separately stated) |
| Water type | ABR effluent (raw anaerobic-baffled-reactor domestic wastewater effluent; no water or fertilizer added, p.2-3) |
| Daily Water exchange rate | NR (nutrient solution replaced every 2 weeks at early growth stage, then weekly at mature stage — a replacement schedule, not a stated fractional daily exchange rate, p.3) |
| Dissolved Oxigen | 3.2 +/- 0.06 |
| EC | 799 +/- 15.56 |
| TAN / NH4-N | 24 +/- 2.82 |
| NO3-N | 0.74 +/- 0.08 |
Plant
| Field | Value |
|---|---|
| Plant | Tomato (Lycopersicum solanum), cv. ‘Monica’ (determinate) |
| Details | Two-week-old seedlings transplanted into 7 cm diameter x 15 cm height pots filled with pine shavings; grown in a polyethylene tunnel March-June 2019; fruits harvested weekly from 72-106 days after transplanting (DAT); shoot biomass/mineral sampling destructive at 106 DAT (p.2-4) |
| Days Plant after transplant | 106 (destructive shoot-biomass/mineral sampling, p.4); fruit harvested weekly from 72-106 DAT |
| SPAD (aquaponics) | 33.67b |
| Plant height | 50.33a |
System & Setup
| Field | Value |
|---|---|
| System type | Media-based hydroponic system (pine shavings substrate in pots); recirculating nutrient tank (100 L) + submersible pump + filter; drip irrigation (2 L/hour emitters, 6 x 5-min intervals/day via timer) (p.2) |
| Media Details | Planting pots, 7 cm diameter x 15 cm height, filled with pine shavings substrate (p.2) |
| pH Buffers | N (Paper states explicitly that pH and EC were measured daily but ‘no adjustments were made to stabilize the nutrient solutions in the hydroponic system’ (p.4)) |
| Climate control | Y (Polyethylene tunnel; average min/max air temperature 13-34 C; daily/night relative humidity 76-82%; no setpoints or active control equipment stated (p.2-3)) |
| Nutrient supplemented | N (ABR effluent used unamended as the sole nutrient source, no fertilizer added (p.2-3)) |
| Equipment | Submersible pump; drip irrigation system with timer (2 L/hour emitters, 6x5min/day); in-line filter; nutrient solution tank (100 L); SPAD-502 chlorophyll meter (Minolta Corp.); LAI-2200 Plant Canopy Analyser (LI-COR); LI-6400XT Portable Photosynthesis System + 6400-04B leaf chamber fluorimeter + 6400-01 CO2 injector (LI-COR Biosciences) (p.2,4-5) |
| Control Parameters | Complete randomised design (CRD), 3 nutrient-source treatments x 3 replicates; pH and EC of nutrient solutions measured daily but explicitly NOT adjusted (‘no adjustments were made to stabilize the nutrient solutions’, p.4); nutrient solutions replaced every 2 weeks at early development stage, then weekly at mature growth stage (p.3) |
| Combination | Tomato (cv. Monica) grown in three parallel media-based hydroponic units differing only in nutrient source: ABR wastewater effluent, commercial hydroponic fertilizer mix (CHFM, the paper’s control), and 50:50 ABR+CHFM; NO fish or aquaculture component in any arm of this paper |
Site
| Field | Value |
|---|---|
| Region | Africa |
| Country | South Africa |
| Average room Temperature | 13-34 (range only, no trial mean reported; min/max tunnel air temperature over the growing period, p.2) |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | cm plant-1 (plant height); dimensionless (LAI); mm (stem diameter); count (no. of stems); SPAD units (chlorophyll content index, CCI); umol m-2 s-1 (photosynthetic rate A); mg/g and mg/kg (shoot macro/micronutrients, Table 3, routed to plant.csv); g/plant, g fw/plant, fruit count, fruit mass (Figure 2 a-f, bar-chart only, no printed values - see remarks) |
| Statistic Details | One-way ANOVA; means separated by Fischer’s Least Significant Difference (LSD) test at P=0.05; Genstat version 18 (VSN International, Hemel Hempstead, UK) (p.4) |
| Statistically analysed | Y |
| Replicates (n) | 3 (stated experimental replicates, p.3); Table 2 growth-parameter pooled n=15, Table 1 water-chemistry pooled n=9 — different pooled sample sizes for different measurement types, not a contradiction |
Experimental Remarks: TRIAL DEFINITION: T1 = ABR effluent treatment (raw anaerobic-baffled-reactor domestic wastewater effluent, no water or fertilizer added, used as the sole nutrient source). Paired control = CHFM (commercial hydroponic fertilizer mix: Hygroponic(R) 0.8kg + Solucal(R) 6.2kg per 1000L municipal tap water; explicitly named ‘used as a control for the experiment’, p.3), recorded in the HYD-side columns/remarks. This paper has NO aquaponic or aquaculture component of any kind — it is pure wastewater-fertigation hydroponics; ‘AP’ in this row’s judgment-call framing denotes the non-standard/wastewater-fed arm (ABR effluent), not aquaponics. | NO AQUAPONIC/AQUACULTURE COMPONENT: entire Fish block set to NA. Aq pH also set to NA — the schema defines Aq pH as the ‘aquaponic loop’ pH, and this paper has no aquaponic loop, biofilter, or fish-tank compartment of any kind (unlike e.g. a bioponic system with a biofilter sump, all three treatments here are identical simple hydroponic recirculation units differing only by influent) — this is a judgment call, flagged for the user. | Dissolved Oxygen, EC, TAN/NH4-N, NO3-N recorded here are the FOCAL (ABR effluent) treatment’s own nutrient-solution values from Table 1 (n=9): DO 3.2+/-0.06, EC 799+/-15.56, Ammonium-N 24+/-2.82, Nitrate-N 0.74+/-0.08 (all mg/L per Table 1’s stated unit, except EC — see WARN-MINOR below). This is a judgment call: these columns are not explicitly restricted to an ‘aquaponic loop’ in their definitions (unlike Aq pH), so they are used here for the trial’s own hydroponic nutrient solution. The paired CHFM control’s matching values (Table 1): DO 3.4+/-0.08, EC 1531+/-13.44, Ammonium-N 5.30+/-0.75, Nitrate-N 63.4+/-1.10, pH 6.93+/-0.05 mg/L — no dedicated ‘HYD water quality’ column exists in this schema, so these control-side values are recorded here only, not in a dedicated cell. | WARN-MINOR EC/pH unit header mismatch: Table 1’s header reads ‘Parameter (mg/l)’ applied uniformly to all 18 rows including EC, pH and DO, which cannot physically be mg/L. Very likely a table-formatting shortcut (the mg/L header genuinely applies only to the ionic/nutrient rows) rather than a real measurement error; no second conflicting value exists to compare against, so this is not a value conflict, just an unclear-unit note. EC (799, 1531, 1532 for ABR/CHFM/ABR+CHFM) is recorded here exactly as printed, NOT converted to dS/m, because the true measurement unit (almost certainly uS/cm) is never explicitly stated — converting would require assuming an unstated unit, which is not permitted. Flagged, no cell blocked. | NOT DERIVED, left NR: Water recycle (pump named, no flow rate stated); Plants/m2 (bed dimensions 15x0.5x0.9 m given, plant count/spacing never stated); Water temperature (only tunnel AIR temperature min/max given, distinct from nutrient-solution temperature, which is never measured); Daily Water exchange rate as a % (only a replacement-schedule cadence given: every 2 weeks then weekly, not a fractional daily rate). | Plant height and SPAD (=Chlorophyll Content Index, CCI, measured with a SPAD-502 meter) recorded at the HARVEST growth stage only (Table 2, n=15): ABR effluents PH 50.33a cm, CCI 33.67b. Seedling-stage (PH 20.57a, CCI 36.54b) and vegetative-stage (PH 25.80a, CCI 40.67b) values for this treatment, plus LAI (0.703a/0.963a/1.44a), stem diameter (3.70a/4.23a/7.59a mm) and number of stems (1.0a/1.0a/2.4a) at all three stages, and photosynthetic rate A (28.79a/29.49a/21.62a umol m-2 s-1) have NO COLUMN home in this schema and are recorded here only, not extracted elsewhere. | NO COLUMN (Table 1, ABR effluent’s own full water-chemistry panel, no dedicated column beyond NH4-N/NO3-N/DO/EC): Total phosphorus 5.46+/-0.73, Potassium 17.2+/-0.96, Calcium 24+/-2.37, Magnesium 10.8+/-1.20, Sulphur 15.0+/-1.41, Iron 135.0+/-14.00, Manganese 41.0+/-2.67, Sodium 109.0+/-12.02, Copper 15.9+/-1.48, Zinc 15.7+/-2.77 mg/L; BOD 18.0+/-1.41, COD 127.0+/-7.78, TSS 18+/-1.41 mg/L; pH 7.86+/-0.16. | NOT DERIVED, left NR: shoot fresh weight, shoot dry weight, total biomass, fruit yield, fruit number, fruit mass — ALL given ONLY as Figure 2 (a-f) bar charts with P-value and LSD printed per panel (Fig.2a P<0.001 LSD=111.5; 2b P<0.001 LSD=19.76; 2c P<0.001 LSD=581.5; 2d P<0.001 LSD=553; 2e P<0.001 LSD=14.79; 2f P<0.001 LSD=14.79 [sic, printed under panel f without its own number in the source, see note]), but NO printed numeric bar values exist in text or a table for any treatment. Per the ‘never read values off a figure’ rule, all six outcomes are left NR here (Plant fresh weight, Plant dry matter, AP, HYD) rather than estimated from bar heights. The paper’s own qualitative text does state ABR effluent was ‘significantly higher’/‘lowest’ vs the other two treatments for all six outcomes (p.5-6), and gives two numeric % deltas for OTHER variables: plant height +4.23% and LAI +26% for ABR+CHFM vs ABR effluent (p.5) — these do not resolve the missing Figure 2 point values and are noted here as text-only context, not entered as cell values (they are relative percentages, not absolute point values, and converting them to absolute values would be derivation). | Nutrient solution changed every 2 weeks (early stage) / weekly (mature stage), p.3 — see Daily Water exchange rate above. | Fish Category, Water classification, Plant Category, Lat/Long, Iron supplemented, Remineralization, Air supplement, Artificial Lighting — all NR, paper silent.
magwazaPartiallyTreatedDomestic2020-T2
Water
| Field | Value |
|---|---|
| Water volume in the system | 100 L (nutrient solution tank capacity per hydroponic unit, p.2; growth-bed liquid volume not separately stated) |
| Water type | ABR effluent + CHFM (50:50 v/v); half-dose commercial fertilizer top-up (40g Hygroponic(R) + 31g Solucal(R) per 100L) added to ABR effluent, no additional water (p.3) |
| Daily Water exchange rate | NR (nutrient solution replaced every 2 weeks at early growth stage, then weekly at mature stage — a replacement schedule, not a stated fractional daily exchange rate, p.3) |
| Dissolved Oxigen | 3.3 +/- 0.07 |
| EC | 1532 +/- 14.14 |
| TAN / NH4-N | 38.0 +/- 2.62 |
| NO3-N | 27.6 +/- 1.84 |
Plant
| Field | Value |
|---|---|
| Plant | Tomato (Lycopersicum solanum), cv. ‘Monica’ (determinate) |
| Details | Two-week-old seedlings transplanted into 7 cm diameter x 15 cm height pots filled with pine shavings; grown in a polyethylene tunnel March-June 2019; fruits harvested weekly from 72-106 days after transplanting (DAT); shoot biomass/mineral sampling destructive at 106 DAT (p.2-4) |
| Days Plant after transplant | 106 (destructive shoot-biomass/mineral sampling, p.4); fruit harvested weekly from 72-106 DAT |
| SPAD (aquaponics) | 29.30a |
| Plant height | 58.80c |
System & Setup
| Field | Value |
|---|---|
| System type | Media-based hydroponic system (pine shavings substrate in pots); recirculating nutrient tank (100 L) + submersible pump + filter; drip irrigation (2 L/hour emitters, 6 x 5-min intervals/day via timer) (p.2) |
| Media Details | Planting pots, 7 cm diameter x 15 cm height, filled with pine shavings substrate (p.2) |
| pH Buffers | N (Paper states explicitly that pH and EC were measured daily but ‘no adjustments were made to stabilize the nutrient solutions in the hydroponic system’ (p.4)) |
| Climate control | Y (Polyethylene tunnel; average min/max air temperature 13-34 C; daily/night relative humidity 76-82%; no setpoints or active control equipment stated (p.2-3)) |
| Nutrient supplemented | Y (50% dose of commercial hydroponic fertilizer mix (CHFM: Hygroponic(R)+Solucal(R), 40g+31g per 100L) added to ABR wastewater effluent (p.3)) |
| Equipment | Submersible pump; drip irrigation system with timer (2 L/hour emitters, 6x5min/day); in-line filter; nutrient solution tank (100 L); SPAD-502 chlorophyll meter (Minolta Corp.); LAI-2200 Plant Canopy Analyser (LI-COR); LI-6400XT Portable Photosynthesis System + 6400-04B leaf chamber fluorimeter + 6400-01 CO2 injector (LI-COR Biosciences) (p.2,4-5) |
| Control Parameters | Complete randomised design (CRD), 3 nutrient-source treatments x 3 replicates; pH and EC of nutrient solutions measured daily but explicitly NOT adjusted (‘no adjustments were made to stabilize the nutrient solutions’, p.4); nutrient solutions replaced every 2 weeks at early development stage, then weekly at mature growth stage (p.3) |
| Combination | Tomato (cv. Monica) grown in three parallel media-based hydroponic units differing only in nutrient source: ABR wastewater effluent, commercial hydroponic fertilizer mix (CHFM, the paper’s control), and 50:50 ABR+CHFM; NO fish or aquaculture component in any arm of this paper |
Site
| Field | Value |
|---|---|
| Region | Africa |
| Country | South Africa |
| Average room Temperature | 13-34 (range only, no trial mean reported; min/max tunnel air temperature over the growing period, p.2) |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | cm plant-1 (plant height); dimensionless (LAI); mm (stem diameter); count (no. of stems); SPAD units (chlorophyll content index, CCI); umol m-2 s-1 (photosynthetic rate A); mg/g and mg/kg (shoot macro/micronutrients, Table 3, routed to plant.csv); g/plant, g fw/plant, fruit count, fruit mass (Figure 2 a-f, bar-chart only, no printed values - see remarks) |
| Statistic Details | One-way ANOVA; means separated by Fischer’s Least Significant Difference (LSD) test at P=0.05; Genstat version 18 (VSN International, Hemel Hempstead, UK) (p.4) |
| Statistically analysed | Y |
| Replicates (n) | 3 (stated experimental replicates, p.3); Table 2 growth-parameter pooled n=15, Table 1 water-chemistry pooled n=9 — different pooled sample sizes for different measurement types, not a contradiction |
Experimental Remarks: TRIAL DEFINITION: T2 = ABR+CHFM treatment (50:50 v/v mix of ABR effluent and CHFM, i.e. a half-dose commercial fertilizer top-up: 40g Hygroponic(R) + 31g Solucal(R) per 100L, added to ABR effluent, no additional water, p.3). Paired control = CHFM (same control as T1; commercial hydroponic fertilizer mix, 80g Hygroponic(R) + 62g Solucal(R) per 100L municipal tap water, explicitly the paper’s stated control), recorded in the HYD-side columns/remarks. This paper has NO aquaponic or aquaculture component of any kind — it is pure wastewater-fertigation hydroponics; ‘AP’ in this row’s judgment-call framing denotes the non-standard/wastewater-fed arm (ABR+CHFM), not aquaponics. | NO AQUAPONIC/AQUACULTURE COMPONENT: entire Fish block set to NA. Aq pH also set to NA — same reasoning as T1 (no aquaponic loop, biofilter, or fish-tank compartment exists anywhere in this paper); judgment call, flagged for the user. | Dissolved Oxygen, EC, TAN/NH4-N, NO3-N recorded here are the FOCAL (ABR+CHFM) treatment’s own nutrient-solution values from Table 1 (n=9): DO 3.3+/-0.07, EC 1532+/-14.14, Ammonium-N 38.0+/-2.62, Nitrate-N 27.6+/-1.84 (mg/L per Table 1’s stated unit, except EC — see WARN-MINOR below). Same judgment call as T1: these columns are used for the trial’s own tested hydroponic solution since their definitions are not explicitly restricted to an ‘aquaponic loop’ (unlike Aq pH). The paired CHFM control’s matching values (Table 1, same as noted in T1): DO 3.4+/-0.08, EC 1531+/-13.44, Ammonium-N 5.30+/-0.75, Nitrate-N 63.4+/-1.10, pH 6.93+/-0.05 mg/L — no dedicated ‘HYD water quality’ column exists in this schema. | WARN-MINOR EC/pH unit header mismatch: identical issue as T1 — Table 1’s header ‘Parameter (mg/l)’ cannot physically apply to EC, pH or DO rows; very likely a table-formatting shortcut, not a real value conflict. EC (1532 for this treatment) recorded exactly as printed, not converted to dS/m since the true unit (likely uS/cm) is never explicitly stated. Flagged, no cell blocked. | NOT DERIVED, left NR: Water recycle, Plants/m2, Water temperature, Daily Water exchange rate as a % — same reasoning as T1. | Plant height and SPAD (CCI, SPAD-502 meter) recorded at the HARVEST growth stage only (Table 2, n=15): ABR+CHFM PH 58.80c cm, CCI 29.30a. Seedling-stage (PH 25.17b, CCI 41.76c) and vegetative-stage (PH 31.33[superscript C, capitalised in source table — printed exactly as shown, likely a typographical variant of lowercase ‘c’], CCI 34.30a) values for this treatment, plus LAI (1.729c/2.148c/3.22c), stem diameter (3.77a/4.84a/8.32a mm) and number of stems (1.0a/2.0a/3.0b) at all three stages, and photosynthetic rate A (28.76a/32.10a/28.17a umol m-2 s-1) have NO COLUMN home in this schema and are recorded here only. WARN-MINOR: Table 2’s vegetative-stage LAI letter for CHFM+ABR is printed as a capital ‘C’ (31.33C) while every other cell in the table uses lowercase superscript letters (a/b/c) — almost certainly a typesetting inconsistency, not a distinct fifth significance group; does not affect any extracted trials.csv cell (LAI has no dedicated column), noted for the record only. | NO COLUMN (Table 1, ABR+CHFM’s own full water-chemistry panel, no dedicated column beyond NH4-N/NO3-N/DO/EC): Total phosphorus 13.4+/-1.90, Potassium 69.0+/-4.16, Calcium 47.0+/-1.37, Magnesium 17.5+/-2.12, Sulphur 33.0+/-2.82, Iron 191+/-12.64, Manganese 72.0+/-3.96, Sodium 130.0+/-13.4, Copper 61.0+/-4.24, Zinc 65.0+/-4.24 mg/L; BOD 11.0+/-1.41, COD 135.0+/-2.83, TSS 11+/-1.41 mg/L; pH 7.77+/-0.04. | NOT DERIVED, left NR: shoot fresh weight, shoot dry weight, total biomass, fruit yield, fruit number, fruit mass — ALL Figure 2 (a-f) bar-chart-only data, same as T1 (see T1 remarks for full LSD/P-value listing per panel). Text states ABR+CHFM ‘had similar performance’ to CHFM on these outcomes (p.6), a qualitative statement only; the two numeric % deltas given in text (plant height +1.59%, LAI +13% for ABR+CHFM vs CHFM, p.5) are relative percentages, not absolute point values, and are noted here as text-only context, not entered as cell values. | Fish Category, Water classification, Plant Category, Lat/Long, Iron supplemented, Remineralization, Air supplement, Artificial Lighting — all NR, paper silent.
Plant Measurements
| Trial | System | Category | Analyte | Value | Unit | Sig. | Location |
|---|---|---|---|---|---|---|---|
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Nitrogen (N) | 28.8 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Phosphorus (P) | 4.3 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Potassium (K) | 9.1 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Magnesium (Mg) | 9.3 | mg/g | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Calcium (Ca) | 24.8 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Iron (Fe) | 216 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Zinc (Zn) | 44 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Copper (Cu) | 945.5 | mg/kg | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Manganese (Mn) | 217.0 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | ABR effluent | mineral | Sodium (Na) | 6992.7 | mg/kg | NR | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Nitrogen (N) | 38.2 | mg/g | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Phosphorus (P) | 6.3 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Potassium (K) | 45.6 | mg/g | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Magnesium (Mg) | 6.9 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Calcium (Ca) | 35.4 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Iron (Fe) | 161 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Zinc (Zn) | 70 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Copper (Cu) | 389.7 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Manganese (Mn) | 166.0 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T1 | CHFM | mineral | Sodium (Na) | 2496.8 | mg/kg | NR | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Nitrogen (N) | 34.8 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Phosphorus (P) | 5.8 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Potassium (K) | 37.7 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Magnesium (Mg) | 8.1 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Calcium (Ca) | 33.6 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Iron (Fe) | 224 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Zinc (Zn) | 81 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Copper (Cu) | 631.0 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Manganese (Mn) | 201.0 | mg/kg | ab | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | ABR+CHFM | mineral | Sodium (Na) | 7371.7 | mg/kg | NR | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Nitrogen (N) | 38.2 | mg/g | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Phosphorus (P) | 6.3 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Potassium (K) | 45.6 | mg/g | c | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Magnesium (Mg) | 6.9 | mg/g | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Calcium (Ca) | 35.4 | mg/g | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Iron (Fe) | 161 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Zinc (Zn) | 70 | mg/kg | b | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Copper (Cu) | 389.7 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Manganese (Mn) | 166.0 | mg/kg | a | Table 3, p.6 |
| magwazaPartiallyTreatedDomestic2020-T2 | CHFM | mineral | Sodium (Na) | 2496.8 | mg/kg | NR | Table 3, p.6 |