Abstract
Sewage sludge is the solid residue obtained from urban sewage treatment plants. It is possible to use the sludge in a sustainable way as fertilizer and as soil conditioner due to its high levels of organic matter and nutrients. Besides pathogens and volatile organic compounds, the residue may also contain heavy metals which may accumulate and contaminate crops and the food chain. The aim of this study was evaluates the changes in the fertility of dystrophic Red Latosol and in the availability of heavy metals following application of sewage sludge. It was assessed whether organic matter supplied to the soil as large amounts of sewage sludge would decrease availability of heavy metals in the soil due to of insoluble compounds formation. From this, an experiment was carried out in polyethylene pots using lettuce plant for test. Sewage sludge were applied to the soil in concentrations equivalent to 60, 120 and 180 t ha-1, and a control without sludge, in four replicates, in a completely randomized design. The results show that sewage sludge led to an increase of organic matter contents, of the cation exchange capacity (CEC) and of nutrients found in the soil. It also improved plant growth up to a concentration of 120 t ha-1. Availability of heavy metals, however, was reduced in sludge concentrations starting with 120 t ha-1.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 5
Claim · model-written summary
Sewage sludge increased soil organic matter contents.
- Taxon
- lettuce plant
Lactuca sativae1 - Treatment
- sewage sludgee0
- Outcome
- organic matter contentse0
- Direction
- increasee0
- Comparator
- control without sludgee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge led to an increase of organic matter contents, of the cation exchange capacity (CEC) and of nutrients found in the soil”
e1“using lettuce plant for test”
e2“a control without sludge”
Claim · model-written summary
Sewage sludge increased soil cation exchange capacity.
- Taxon
- lettuce plantLactuca sativae1
- Treatment
- sewage sludgee0
- Outcome
- cation exchange capacity (CEC)e0
- Direction
- increasee0
- Comparator
- control without sludgee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge led to an increase of organic matter contents, of the cation exchange capacity (CEC) and of nutrients found in the soil”
e1“using lettuce plant for test”
e2“a control without sludge”
Claim · model-written summary
Sewage sludge increased nutrients found in the soil.
- Taxon
- lettuce plantLactuca sativae1
- Treatment
- sewage sludgee0
- Outcome
- nutrients found in the soile0
- Direction
- increasee0
- Comparator
- control without sludgee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“sewage sludge led to an increase of organic matter contents, of the cation exchange capacity (CEC) and of nutrients found in the soil”
e1“using lettuce plant for test”
e2“a control without sludge”
Claim · model-written summary
Sewage sludge improved lettuce growth up to a concentration of 120 t ha-1.
- Taxon
- lettuce plantLactuca sativae1
- Treatment
- Sewage sludgee3
- Outcome
- plant growthe0
- Direction
- improvede0
- Value
- 120 t ha-1e0
- Comparator
- control without sludgee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“It also improved plant growth up to a concentration of 120 t ha-1.”
e1“using lettuce plant for test”
e2“a control without sludge”
e3“Sewage sludge were applied to the soil”
Claim · model-written summary
Heavy metal availability decreased at sludge concentrations starting with 120 t ha-1.
- Taxon
- lettuce plantLactuca sativae1
- Treatment
- sludge concentrations starting with 120 t ha-1e0
- Outcome
- Availability of heavy metalse0
- Direction
- reducede0
- Value
- 120 t ha-1e0
- Comparator
- control without sludgee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Availability of heavy metals, however, was reduced in sludge concentrations starting with 120 t ha-1.”
e1“using lettuce plant for test”
e2“a control without sludge”
The same questions in other papers
organic · growth · Lactuca sativa (garden lettuce)Positive and negative results
11 papers in the same direction as this paper · 5 in the opposite direction
- negative
- negative
- no effect
13 papers more in this group
See all 17 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.