Abstract
In this study, we present the response of spinach to different amendment rates of sewage sludge (0, 10, 20, 30, 40 and 50 g kg−1) in a greenhouse pot experiment, where plant growth, biomass and heavy metal uptake were measured. The results showed that sewage sludge application increased soil electric conductivity (EC), organic matter, chromium and zinc concentrations and decreased soil pH. All heavy metal concentrations of the sewage sludge were below the permissible limits for land application of sewage sludge recommended by the Council of the European Communities. Biomass and all growth parameters (except the shoot/root ratio) of spinach showed a positive response to sewage sludge applications up to 40 g kg−1 compared to the control soil. Increasing the sewage sludge amendment rate caused an increase in all heavy metal concentrations (except lead) in spinach root and shoot. However, all heavy metal concentrations (except chromium and iron) were in the normal range and did not reach the phytotoxic levels. The spinach was characterized by a bioaccumulation factor <1.0 for all heavy metals. The translocation factor (TF) varied among the heavy metals as well as among the sewage sludge amendment rates. Spinach translocation mechanisms clearly restricted heavy metal transport to the edible parts (shoot) because the TFs for all heavy metals (except zinc) were <1.0. In conclusion, sewage sludge used in the present study can be considered for use as a fertilizer in spinach production systems in Saudi Arabia, and the results can serve as a management method for sewage sludge.
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Claims 10
Claim · model-written summary
Sewage sludge increased soil electrical conductivity, organic matter, chromium and zinc and decreased soil pH.
- Taxon
- spinach
Spinacia oleraceat0 - Treatment
- sewage sludge applicatione0
- Outcome
- soil electric conductivity (EC), organic matter, chromium and zinc concentrationse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge application increased soil electric conductivity (EC), organic matter, chromium and zinc concentrations and decreased soil pH.”
t0“spinach (Spinacia oleracea L.)”
Claim · model-written summary
Sewage sludge decreased soil pH.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- sewage sludge applicatione0
- Outcome
- soil pHe0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge application increased soil electric conductivity (EC), organic matter, chromium and zinc concentrations and decreased soil pH.”
t0“spinach (Spinacia oleracea L.)”
Claim · model-written summary
Heavy metal concentrations in sewage sludge were below permissible land application limits.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- heavy metal concentrations of the sewage sludgee0
- Direction
- belowe0
- Comparator
- permissible limitse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All heavy metal concentrations of the sewage sludge were below the permissible limits for land application of sewage sludge recommended by the Council of the European Communities.”
t0“spinach (Spinacia oleracea L.)”
Claim · model-written summary
Spinach biomass and growth parameters other than shoot/root ratio increased with sludge up to 40 g kg−1 versus control soil.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- sewage sludge applications up to 40 g kg−1e0
- Outcome
- Biomass and all growth parameters (except the shoot/root ratio)e0
- Direction
- positive responsee0
- Comparator
- control soile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biomass and all growth parameters (except the shoot/root ratio) of spinach showed a positive response to sewage sludge applications up to 40 g kg−1 compared to the control soil.”
Claim · model-written summary
Increasing sludge application raised all heavy metal concentrations except lead in spinach roots and shoots.
- Taxon
- spinachSpinacia oleraceae0
- Organ / stage
- root and shoote0
- Treatment
- sewage sludge amendment ratee0
- Outcome
- all heavy metal concentrations (except lead)e0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Increasing the sewage sludge amendment rate caused an increase in all heavy metal concentrations (except lead) in spinach root and shoot.”
Claim · model-written summary
All measured heavy metals except chromium and iron were in the normal range and below phytotoxic levels.
- Taxon
- spinachSpinacia oleraceat0
- Outcome
- heavy metal concentrations (except chromium and iron)e0
- Direction
- did not reache0
- Comparator
- phytotoxic levelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all heavy metal concentrations (except chromium and iron) were in the normal range and did not reach the phytotoxic levels.”
t0“spinach (Spinacia oleracea L.)”
Claim · model-written summary
Spinach bioaccumulation factor was below 1.0 for all heavy metals.
- Taxon
- spinachSpinacia oleraceae0
- Outcome
- bioaccumulation factore0
- Value
- <1.0e0
- Qualifier
- for all heavy metalse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The spinach was characterized by a bioaccumulation factor <1.0 for all heavy metals.”
Claim · model-written summary
The translocation factor varied across heavy metals and sludge amendment rates.
- Taxon
- spinachSpinacia oleraceat0
- Treatment
- sewage sludge amendment ratese0
- Outcome
- translocation factor (TF)e0
- Qualifier
- heavy metalse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The translocation factor (TF) varied among the heavy metals as well as among the sewage sludge amendment rates.”
t0“spinach (Spinacia oleracea L.)”
Claim · model-written summary
The translocation factor for all heavy metals except zinc was below 1.0, indicating restricted transport to spinach shoots.
- Taxon
- SpinachSpinacia oleraceae0
- Organ / stage
- shoote0
- Outcome
- TFs for all heavy metals (except zinc)e0
- Direction
- restrictede0
- Value
- <1.0e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Spinach translocation mechanisms clearly restricted heavy metal transport to the edible parts (shoot) because the TFs for all heavy metals (except zinc) were <1.0.”
Claim · model-written summary
The authors recommend considering this sewage sludge as fertilizer for spinach production in Saudi Arabia.
- Taxon
- spinachSpinacia oleraceae0
- Treatment
- sewage sludgee0
- Outcome
- use as a fertilizer in spinach production systemse0
- Setting
- Saudi Arabiae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge used in the present study can be considered for use as a fertilizer in spinach production systems in Saudi Arabia”
The same questions in other papers
organic · growth · Spinacia oleracea (spinach)Results agree
6 papers in the same direction as this paper
- positive
- positive
- positive
3 papers more in this group
See all 7 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.