Abstract
Abstract Field experiments were conducted to determine the effects of superphosphate and organic matter in preventing the accumulation of toxic residues where Cyanamid was used for weed control in tobacco plantbeds on heavy silt loam soils of central Kentucky. Toxic materials or conditions in some cases following treatment with Cyanamid resulted in stunted tobacco seedlings or even death. Soil conditions where seedling injury was noted include soil pH above 8 and ammonium‐N concentration exceeding 350 ppm. of soil at seeding time (about April 1). Three‐fourths pound per square yard of 20% superphosphate applied with the Cyanamid decreased soil pH and ammonium‐N concentration, resulting in improved plant growth. Organic matter decreased soil pH and ammonium‐N content, but not until May which is too late for seeding. In laboratory studies ammonium ions from the decomposition of Cyanamid were more readily leached from the soil when superphosphate or other materials supplying cations had been added. Leaching ammonium‐N from the soil resulted in improved plant growth particularly when superphosphate had been used. In greenhouse studies ammonium‐N in soil was found to be toxic to tobacco seedings, particularly at high soil pH as occurs when Cyanamid (equivalent to 70% calcium hydroxide) is applied to soil in sufficient quantity to act as a weed control agent.
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Claims 8
Claim · model-written summary
Cyanamid-associated toxic conditions stunted or killed tobacco seedlings.
- Taxon
- tobacco
Nicotiana tabacume0 - Treatment
- Cyanamide0
- Outcome
- stunted tobacco seedlings or even deathe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Toxic materials or conditions in some cases following treatment with Cyanamid resulted in stunted tobacco seedlings or even death”
Claim · model-written summary
Injured seedlings occurred with soil pH above 8 and ammonium-N above 350 ppm.
- Taxon
- tobaccoNicotiana tabacume1
- Outcome
- seedling injurye0
- Qualifier
- soil pH above 8 and ammonium‐N concentration exceeding 350 ppm.e0
- Setting
- soile0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Soil conditions where seedling injury was noted include soil pH above 8 and ammonium‐N concentration exceeding 350 ppm. of soil at seeding time”
e1“Toxic materials or conditions in some cases following treatment with Cyanamid resulted in stunted tobacco seedlings or even death”
Claim · model-written summary
Superphosphate with Cyanamid lowered soil pH and ammonium-N.
- Taxon
- TobaccoNicotiana tabacumt0
- Treatment
- Three‐fourths pound per square yard of 20% superphosphate applied with the Cyanamide0
- Outcome
- soil pH and ammonium‐N concentratione0
- Direction
- decreasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Three‐fourths pound per square yard of 20% superphosphate applied with the Cyanamid decreased soil pH and ammonium‐N concentration, resulting in improved plant growth”
t0“Tobacco”
Claim · model-written summary
Superphosphate with Cyanamid improved plant growth.
- Taxon
- TobaccoNicotiana tabacumt0
- Treatment
- Three‐fourths pound per square yard of 20% superphosphate applied with the Cyanamide0
- Outcome
- plant growthe0
- Direction
- improvede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Three‐fourths pound per square yard of 20% superphosphate applied with the Cyanamid decreased soil pH and ammonium‐N concentration, resulting in improved plant growth”
t0“Tobacco”
Claim · model-written summary
Organic matter lowered soil pH and ammonium-N only by May.
- Taxon
- TobaccoNicotiana tabacumt0
- Treatment
- Organic mattere0
- Outcome
- soil pH and ammonium‐N contente0
- Direction
- decreasede0
- Qualifier
- not until May which is too late for seedinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Organic matter decreased soil pH and ammonium‐N content, but not until May which is too late for seeding”
t0“Tobacco”
Claim · model-written summary
Ammonium ions leached more readily with superphosphate or other cation sources.
- Taxon
- TobaccoNicotiana tabacumt0
- Treatment
- superphosphate or other materials supplying cationse0
- Outcome
- ammonium ions from the decomposition of Cyanamide0
- Direction
- more readily leachede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ammonium ions from the decomposition of Cyanamid were more readily leached from the soil when superphosphate or other materials supplying cations had been added”
t0“Tobacco”
Claim · model-written summary
Leaching soil ammonium-N improved growth, especially with superphosphate.
- Taxon
- TobaccoNicotiana tabacumt0
- Treatment
- Leaching ammonium‐N from the soile0
- Outcome
- plant growthe0
- Direction
- improvede0
- Qualifier
- particularly when superphosphate had been usede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Leaching ammonium‐N from the soil resulted in improved plant growth particularly when superphosphate had been used”
t0“Tobacco”
Claim · model-written summary
Soil ammonium-N was toxic to tobacco seedlings, especially at high pH.
- Taxon
- tobaccoNicotiana tabacume0
- Outcome
- toxic to tobacco seedingse0
- Qualifier
- particularly at high soil pHe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“ammonium‐N in soil was found to be toxic to tobacco seedings, particularly at high soil pH”
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