Abstract
Abstract Treble superphosphate (TSP) was applied at 0 and 120 kg P/ha to a highly weathered Oxisol which had received various levels of a sewage sludge 5 years earlier. Lettuce (Lactuca sativa L.) was grown as a test crop. Plant and soil chemical composition indicated that the efficiency of TSP was significantly increased in the presence of sludge: 120 kg P/ha added to soils amended with 45, 90, and 180 Mg/ha sludge were correspondingly as effective as 306, 314, and 196 kg P/ha as TSP required by the unamended soils. This is probably because organic anions and molecules produced by the sludge reacted with P fixing sites on the soil surface and/or chelated‐precipitated soluble Al. Furthermore, increased Ca levels in soil solution by sludge or TSP addition improved plant growth and reduced Al uptake. For lettuce, the adequate Ca range was 400–500 mg/L in soil solution and 1.9–2.0% in leaf. Because of an unexpected additional input, adequate range of soil solution P could not be clearly determined for lettuce, but the plant's internal P requirement appeared to be 0.45–0.50%.
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Claims 10
Claim · model-written summary
Prior sludge increased the fertilizer efficiency of TSP significantly.
- Taxon
- Lettuce
Lactuca sativae1 - Treatment
- sludgee0
- Outcome
- efficiency of TSPe0
- Direction
- increasede0
- Comparator
- unamended soilse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the efficiency of TSP was significantly increased in the presence of sludge: 120 kg P/ha added to soils amended with 45, 90, and 180 Mg/ha sludge were correspondingly as effective as 306, 314, and 196 kg P/ha as TSP required by the unamended soils”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
Sludge-amended soil at 45 Mg/ha made 120 kg P/ha as effective as 306 kg P/ha TSP in unamended soil.
- Taxon
- LettuceLactuca sativae1
- Treatment
- 45e0
- Outcome
- effectivee0
- Direction
- as effective ase0
- Value
- 306e0
- Comparator
- unamended soilse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“120 kg P/ha added to soils amended with 45, 90, and 180 Mg/ha sludge were correspondingly as effective as 306, 314, and 196 kg P/ha as TSP required by the unamended soils”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
Sludge-amended soil at 90 Mg/ha made 120 kg P/ha as effective as 314 kg P/ha TSP in unamended soil.
- Taxon
- LettuceLactuca sativae1
- Treatment
- 90e0
- Outcome
- effectivee0
- Direction
- as effective ase0
- Value
- 314e0
- Comparator
- unamended soilse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“120 kg P/ha added to soils amended with 45, 90, and 180 Mg/ha sludge were correspondingly as effective as 306, 314, and 196 kg P/ha as TSP required by the unamended soils”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
Sludge-amended soil at 180 Mg/ha made 120 kg P/ha as effective as 196 kg P/ha TSP in unamended soil.
- Taxon
- LettuceLactuca sativae1
- Treatment
- 180e0
- Outcome
- effectivee0
- Direction
- as effective ase0
- Value
- 196 kg P/hae0
- Comparator
- unamended soilse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“120 kg P/ha added to soils amended with 45, 90, and 180 Mg/ha sludge were correspondingly as effective as 306, 314, and 196 kg P/ha as TSP required by the unamended soils”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
Increased solution calcium from sludge or TSP improved lettuce growth.
- Taxon
- LettuceLactuca sativae1
- Treatment
- sludge or TSP additione0
- Outcome
- plant growthe0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased Ca levels in soil solution by sludge or TSP addition improved plant growth”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
Increased solution calcium from sludge or TSP reduced lettuce aluminum uptake.
- Taxon
- LettuceLactuca sativae1
- Treatment
- sludge or TSP additione0
- Outcome
- Al uptakee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“increased Ca levels in soil solution by sludge or TSP addition improved plant growth and reduced Al uptake”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
Claim · model-written summary
The adequate soil solution calcium range for lettuce was 400–500 mg/L.
- Taxon
- lettuceLactuca sativae0
- Outcome
- adequate Ca rangee0
- Value
- 400–500 mg/Le0
- Setting
- soil solutione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For lettuce, the adequate Ca range was 400–500 mg/L in soil solution and 1.9–2.0% in leaf”
Claim · model-written summary
The adequate leaf calcium range for lettuce was 1.9–2.0%.
- Taxon
- lettuceLactuca sativae0
- Organ / stage
- leafe0
- Outcome
- adequate Ca rangee0
- Value
- 1.9–2.0%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“For lettuce, the adequate Ca range was 400–500 mg/L in soil solution and 1.9–2.0% in leaf”
Claim · model-written summary
The adequate soil solution phosphorus range for lettuce could not be determined clearly.
- Taxon
- lettuceLactuca sativae0
- Outcome
- adequate range of soil solution Pe0
- Qualifier
- could not be clearly determinede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“adequate range of soil solution P could not be clearly determined for lettuce”
Claim · model-written summary
The internal phosphorus requirement of lettuce appeared to be 0.45–0.50%.
- Taxon
- LettuceLactuca sativae1
- Outcome
- internal P requiremente0
- Value
- 0.45–0.50%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“plant's internal P requirement appeared to be 0.45–0.50%”
e1“Lettuce (Lactuca sativa L.) was grown as a test crop.”
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See all 21 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.