Abstract
Applying polymer-coated urea (PCU) instead of uncoated urea may benefit winter wheat (Triticum aestivum L.) production by reducing weed growth or increasing grain yield and protein concentration. Field trials were conducted for 3 yr under rainfed and irrigated conditions in Lethbridge and 2 yr under rainfed conditions in Lacombe to determine potential benefits of substituting urea with PCU for typical winter wheat production practices in Alberta. Four factors were included in each experiment: (1) urea type (urea, PCU and a 50:50 blend of urea and PCU), (2) application method (fall side-band vs. spring broadcast), (3) N rate (1× and 1.5× recommended N rate), and (4) herbicide application (none vs. full). Herbicide application substantially reduced weed biomass at all site-years, but only increased average grain yield by 9%. Dicot weed biomass was not affected by fertilizer treatment, but monocot weed biomass was less for fall banded than spring broadcast application and less for urea than PCU or blend at the 1× N rate. Over all site-years, substitution of 50 or 100% of urea with PCU increased grain yield by an average of 4.3% and reduced protein concentration by 1.3%. Substitution of urea with PCU had the largest impact at the site-year with most severe drought stress, indicating that PCU benefits were probably due to factors other than reduced N loss. Further study is required to evaluate potential benefits from substitution of urea with PCU over a wide range of environmental conditions.Key words: Triticum aestivum, nitrogen fertilizer, placement, timing, split N, grain protein concentration, polymer-coated urea
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Claims 9
Claim · model-written summary
Herbicide reduced weed biomass across all site-years.
- Taxon
- winter wheat
Triticum aestivumt0 - Treatment
- Herbicide applicatione0
- Interactor
- weede0weed
- Outcome
- weed biomasse0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Herbicide application substantially reduced weed biomass at all site-years”
t0“winter wheat”
Claim · model-written summary
Herbicide raised average grain yield by 9%.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- Herbicide applicatione0
- Outcome
- average grain yielde0
- Direction
- increasede0
- Value
- 9%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Herbicide application substantially reduced weed biomass at all site-years, but only increased average grain yield by 9%.”
t0“winter wheat”
Claim · model-written summary
Fertilizer treatment did not affect dicot weed biomass.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- fertilizer treatmente0
- Interactor
- Dicot weede0weed
- Outcome
- Dicot weed biomasse0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Dicot weed biomass was not affected by fertilizer treatment”
t0“winter wheat”
Claim · model-written summary
Fall banding yielded less monocot weed biomass than spring broadcast application.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- fall bandede0
- Interactor
- monocot weede0weed
- Outcome
- monocot weed biomasse0
- Direction
- lesse0
- Comparator
- spring broadcast applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“monocot weed biomass was less for fall banded than spring broadcast application”
t0“winter wheat”
Claim · model-written summary
At the 1× N rate, urea yielded less monocot weed biomass than PCU or the blend.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- ureae0
- Interactor
- monocot weede0weed
- Outcome
- monocot weed biomasse0
- Direction
- lesse0
- Qualifier
- 1× N ratee0
- Comparator
- PCU or blende0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“monocot weed biomass was less for fall banded than spring broadcast application and less for urea than PCU or blend at the 1× N rate.”
t0“winter wheat”
Claim · model-written summary
Substituting 50 or 100% of urea with PCU raised grain yield by 4.3% on average across site-years.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- substitution of 50 or 100% of urea with PCUe0
- Outcome
- grain yielde0
- Direction
- increasede0
- Value
- 4.3%e0
- Qualifier
- Over all site-yearse0
- Comparator
- ureae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over all site-years, substitution of 50 or 100% of urea with PCU increased grain yield by an average of 4.3% and reduced protein concentration by 1.3%.”
t0“winter wheat”
Claim · model-written summary
Substituting 50 or 100% of urea with PCU reduced protein concentration by 1.3% on average.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- substitution of 50 or 100% of urea with PCUe0
- Outcome
- protein concentratione0
- Direction
- reducede0
- Value
- 1.3%e0
- Qualifier
- Over all site-yearse0
- Comparator
- ureae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Over all site-years, substitution of 50 or 100% of urea with PCU increased grain yield by an average of 4.3% and reduced protein concentration by 1.3%.”
t0“winter wheat”
Claim · model-written summary
The largest PCU substitution impact occurred in the site-year with the most severe drought stress.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- Substitution of urea with PCUe0
- Outcome
- largest impacte0
- Qualifier
- site-year with most severe drought stresse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Substitution of urea with PCU had the largest impact at the site-year with most severe drought stress”
t0“winter wheat”
Claim · model-written summary
The authors infer that PCU benefits were probably due to factors other than reduced nitrogen loss.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- PCUe0
- Outcome
- benefitse0
- Qualifier
- probably due to factors other than reduced N losse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“PCU benefits were probably due to factors other than reduced N loss”
t0“winter wheat”
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