Abstract
In 1982, urea applied on the soil surface with phenylphosphorodiamidate (PPD) was compared with urea alone applied on the surface, urea injected, ammonium sulfate and calcium nitrate with respect to N uptake and yield of corn (Zea mays L.). In 1983, the urease inhibitors trichloroethylphosphorodiamidate (TPD), diethylphosphorotriamide (DPT) and sarsaponin (SSO) were compared in a similar way. In 1982, grain yield, total dry matter, total N uptake and fertilizer N uptake were all higher where PPD was used than with urea alone, but the differences fell short of statistical significance at the 0.05 level. In 1983, total dry matter, grain yield, and total N uptake were all higher in cultivated plots than in zero-tillage plots. None of the urease inhibitors improved N uptake over that from urea alone. The data show little advantage for inhibitors added to urea solutions applied in bands at the surface, but TPD and DPT applied as a coating on broadcast solid urea showed some promise. Soil analyses during the first few days after fertilizer application showed lower recoveries of applied N where wheat (Triticum aestivum L.) straw or corn residues were present than from bare soil, but clear evidence of the influence of urease inhibitors on soil urea levels was not found.
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Claims 11
Claim · model-written summary
PPD increased corn grain yield versus urea alone, without statistical significance.
- Taxon
- corn
Zea mays subsp. mayst0 - Treatment
- PPDe0
- Outcome
- grain yielde0
- Direction
- highere0
- Comparator
- urea alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 1982, grain yield, total dry matter, total N uptake and fertilizer N uptake were all higher where PPD was used than with urea alone, but the differences fell short of statistical significance at the 0.05 level.”
t0“Corn”
Claim · model-written summary
PPD increased corn total dry matter versus urea alone, without statistical significance.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- PPDe0
- Outcome
- total dry mattere0
- Direction
- highere0
- Comparator
- urea alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 1982, grain yield, total dry matter, total N uptake and fertilizer N uptake were all higher where PPD was used than with urea alone, but the differences fell short of statistical significance at the 0.05 level.”
t0“Corn”
Claim · model-written summary
PPD increased corn total and fertilizer nitrogen uptake versus urea alone, without statistical significance.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- PPDe0
- Outcome
- total N uptake and fertilizer N uptakee0
- Direction
- highere0
- Comparator
- urea alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 1982, grain yield, total dry matter, total N uptake and fertilizer N uptake were all higher where PPD was used than with urea alone, but the differences fell short of statistical significance at the 0.05 level.”
t0“Corn”
Claim · model-written summary
Cultivation increased corn total dry matter and grain yield relative to zero tillage.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- cultivated plotse0
- Outcome
- total dry matter, grain yielde0
- Direction
- highere0
- Comparator
- zero-tillage plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 1983, total dry matter, grain yield, and total N uptake were all higher in cultivated plots than in zero-tillage plots.”
t0“Corn”
Claim · model-written summary
Cultivation increased corn nitrogen uptake relative to zero tillage.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- cultivated plotse0
- Outcome
- total N uptakee0
- Direction
- highere0
- Comparator
- zero-tillage plotse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In 1983, total dry matter, grain yield, and total N uptake were all higher in cultivated plots than in zero-tillage plots.”
t0“Corn”
Claim · model-written summary
No tested urease inhibitor improved nitrogen uptake relative to urea alone.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- urease inhibitorse0
- Outcome
- N uptakee0
- Direction
- None of the urease inhibitors improvede0
- Comparator
- urea alonee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“None of the urease inhibitors improved N uptake over that from urea alone.”
t0“Corn”
Claim · model-written summary
Inhibitors added to surface banded urea solution showed little advantage.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- inhibitors added to urea solutions applied in bands at the surfacee0
- Outcome
- little advantagee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The data show little advantage for inhibitors added to urea solutions applied in bands at the surface”
t0“Corn”
Claim · model-written summary
TPD coating on broadcast solid urea showed promise.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- TPDe0
- Outcome
- showed some promisee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“TPD and DPT applied as a coating on broadcast solid urea showed some promise.”
t0“Corn”
Claim · model-written summary
DPT coating on broadcast solid urea showed promise.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- DPTe0
- Outcome
- showed some promisee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“TPD and DPT applied as a coating on broadcast solid urea showed some promise.”
t0“Corn”
Claim · model-written summary
Soils with wheat straw or corn residues had lower applied nitrogen recoveries than bare soil.
- Treatment
- wheat (Triticum aestivum L.) straw or corn residuese0
- Outcome
- recoveries of applied Ne0
- Direction
- lowere0
- Comparator
- bare soile0
Not reportedTaxon
Verbatim
e0“Soil analyses during the first few days after fertilizer application showed lower recoveries of applied N where wheat (Triticum aestivum L.) straw or corn residues were present than from bare soil”
Claim · model-written summary
The soil analyses found no clear effect of urease inhibitors on soil urea levels.
Not reportedTaxonDirection
Verbatim
e0“clear evidence of the influence of urease inhibitors on soil urea levels was not found.”
The same questions in other papers
EC 3.5.1.5 (urease) inhibitor · nutrient: content · Zea mays (maize)Positive and negative results
1 paper in the same direction as this paper · 2 reporting no difference from an alternative
- positive
- positive
- negative
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.