Abstract
Abstract Field experiments comparing the use of urea to other fertilizers were performed. The fertilizer was placed with the seed in all but two experiments. Urea containing 2.5% biuret reduced stands of small grain by 30% when the equivalent of 20 pounds nitrogen per acre was applied with the seed. Ammonium nitrate at 80 pounds nitrogen per acre caused a reduction in stand of 10%. Stands were depressed by 25 and 60% when 40 and 80 pounds nitrogen, respectively, as reagent urea were used per acre. Urea, containing 10% biuret, applied broadcast at 160 pounds nitrogen per acre, caused no damage to germination of either corn or barley. Urea was intermediate between ammonium carbonate (most damaging) and ammonium nitrate in a greenhouse germination trial. When fertilizer was mixed with the soil in the laboratory, considerable ammonia was evolved from the soil atmosphere by aeration when either urea, ammonium hydroxide or ammonium carbonate was used. Only traces of ammonia were removed from soils treated with either ammonium nitrate, ammonium sulfate or biuret. Ammonia gas formed from urea, and the contaminant biuret in urea, are therefore both instrumental in causing commercial urea to be toxic to germinating seeds.
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Claims 8
Claim · model-written summary
Urea with 2.5% biuret reduced small grain stands by 30%.
- Taxon
- small graine0
- Treatment
- Urea containing 2.5% biurete0
- Outcome
- standse0
- Direction
- reducede0
- Value
- 30%e0
- Qualifier
- 20 pounds nitrogen per acree0
Not reportedComparator
Verbatim
e0“Urea containing 2.5% biuret reduced stands of small grain by 30% when the equivalent of 20 pounds nitrogen per acre was applied with the seed”
Claim · model-written summary
Ammonium nitrate at 80 pounds nitrogen per acre reduced stands by 10%.
- Taxon
- Small Grain and Cornt0
- Treatment
- Ammonium nitrate at 80 pounds nitrogen per acree0
- Outcome
- stande0
- Direction
- reductione0
- Value
- 10%e0
Not reportedComparator
Verbatim
e0“Ammonium nitrate at 80 pounds nitrogen per acre caused a reduction in stand of 10%”
t0“Small Grain and Corn”
Claim · model-written summary
Reagent urea at 40 pounds nitrogen per acre depressed stands by 25%.
- Taxon
- Small Grain and Cornt0
- Treatment
- reagent ureae0
- Outcome
- Standse0
- Direction
- depressede0
- Value
- 25e0
- Qualifier
- 40e0
Not reportedComparator
Verbatim
e0“Stands were depressed by 25 and 60% when 40 and 80 pounds nitrogen, respectively, as reagent urea were used per acre”
t0“Small Grain and Corn”
Claim · model-written summary
Reagent urea at 80 pounds nitrogen per acre depressed stands by 60%.
- Taxon
- Small Grain and Cornt0
- Treatment
- reagent ureae0
- Outcome
- Standse0
- Direction
- depressede0
- Value
- 60%e0
- Qualifier
- 80 pounds nitrogene0
Not reportedComparator
Verbatim
e0“Stands were depressed by 25 and 60% when 40 and 80 pounds nitrogen, respectively, as reagent urea were used per acre”
t0“Small Grain and Corn”
Claim · model-written summary
Broadcast urea with 10% biuret did not damage corn germination.
- Taxon
- corn
Zea mays subsp. mayse0 - Treatment
- Urea, containing 10% biuret, applied broadcast at 160 pounds nitrogen per acree0
- Outcome
- germinatione0
- Direction
- no damagee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Urea, containing 10% biuret, applied broadcast at 160 pounds nitrogen per acre, caused no damage to germination of either corn or barley”
Claim · model-written summary
Broadcast urea with 10% biuret did not damage barley germination.
- Taxon
- barley
.jpg?width=60)
Hordeum vulgaree0 - Treatment
- Urea, containing 10% biuret, applied broadcast at 160 pounds nitrogen per acree0
- Outcome
- germinatione0
- Direction
- no damagee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“Urea, containing 10% biuret, applied broadcast at 160 pounds nitrogen per acre, caused no damage to germination of either corn or barley”
Claim · model-written summary
Urea caused intermediate germination damage between ammonium carbonate and ammonium nitrate.
Verbatim
e0“Urea was intermediate between ammonium carbonate (most damaging) and ammonium nitrate in a greenhouse germination trial”
t0“Small Grain and Corn”
Claim · model-written summary
The authors implicate ammonia gas from urea and biuret in toxicity to germinating seeds.
Verbatim
e0“Ammonia gas formed from urea, and the contaminant biuret in urea, are therefore both instrumental in causing commercial urea to be toxic to germinating seeds”
t0“Small Grain and Corn”
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