Abstract
The recent development of low-cost controlled-release urea (CRU) may provide additional options for N fertilization of winter wheat (Triticum aestivum L.). Two field experiments were conducted over 3 yr at three locations in southern Alberta to evaluate different options of applying CRU to winter wheat. In the first experiment, three N fertilizers (20-day CRU, 40-day CRU and urea) were seed-placed and side-banded at the time of seeding at 0, 30, 60, 90 and 120 kg N ha -1 . Stand densities were substantially reduced by seedrow application of urea at rates greater than 30 kg N ha -1 , but were unaffected by seedrow application of CRU, even at the highest rate of N application. When N fertilizer was sidebanded, stand densities were unaffected by fertilizer type or N rate. Yield gains due to N application were reduced by application of high rates of seed-placed urea, but similar for other treatments. Grain protein concentration and N uptake were also similar for CRU and seed-placed urea. In the second experiment, three N fertilizers (CRU, urea and ammonium nitrate) were broadcast at 30 kg N ha -1 in early spring on plots that had received 0, 30 or 60 kg N ha -1 of CRU at the time of seeding. Inadequate release of spring broadcast CRU was indicated by reduced grain protein concentrations relative to conventional N fertilizers. Under the conditions experienced in our study, CRU substantially increased the maximum safe rate of seed-placed urea, provided minimal benefits to N response relative to side-banded urea, and was less effective than conventional N fertilizers when broadcast in early spring. Key words: N fertilizer use efficiency, slow release, winter survival
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Claims 10
Claim · model-written summary
Seedrow application of urea above 30 kg N ha -1 substantially reduced stand densities.
- Taxon
- winter wheat
Triticum aestivumt0 - Treatment
- seedrow application of urea at rates greater than 30 kg N ha -1e1
- Outcome
- Stand densitiese1
- Direction
- substantially reducede1
- Comparator
- seedrow application of CRUe1
- Setting
- southern Albertat0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e1“Stand densities were substantially reduced by seedrow application of urea at rates greater than 30 kg N ha -1 , but were unaffected by seedrow application of CRU”
Claim · model-written summary
Seedrow application of CRU did not change stand densities, even at the highest N rate.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- seedrow application of CRUe1
- Outcome
- Stand densitiese1
- Direction
- unaffectede1
- Comparator
- seedrow application of ureae1
- Setting
- southern Albertat0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e1“Stand densities were substantially reduced by seedrow application of urea at rates greater than 30 kg N ha -1 , but were unaffected by seedrow application of CRU”
Claim · model-written summary
Sidebanded fertilizer left stand densities unaffected by fertilizer type or N rate.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- sidebandede2
- Outcome
- stand densitiese2
- Direction
- unaffectede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e2“When N fertilizer was sidebanded, stand densities were unaffected by fertilizer type or N rate”
Claim · model-written summary
Application of high rates of seed-placed urea reduced yield gains due to N application.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- application of high rates of seed-placed ureae3
- Outcome
- Yield gains due to N applicatione3
- Direction
- reducede3
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e3“Yield gains due to N application were reduced by application of high rates of seed-placed urea, but similar for other treatments”
Claim · model-written summary
Yield gains due to N application were similar for other treatments and high-rate seed-placed urea.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- other treatmentse3
- Outcome
- Yield gains due to N applicatione3
- Direction
- similare3
- Comparator
- application of high rates of seed-placed ureae3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e3“Yield gains due to N application were reduced by application of high rates of seed-placed urea, but similar for other treatments”
Claim · model-written summary
Grain protein concentration and N uptake were similar for CRU and seed-placed urea.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- CRUe4
- Outcome
- Grain protein concentration and N uptakee4
- Direction
- similare4
- Comparator
- seed-placed ureae4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e4“Grain protein concentration and N uptake were also similar for CRU and seed-placed urea”
Claim · model-written summary
Inadequate release of spring broadcast CRU reduced grain protein concentrations relative to conventional N fertilizers.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- spring broadcast CRUe5
- Outcome
- grain protein concentrationse5
- Direction
- reducede5
- Qualifier
- Inadequate releasee5
- Comparator
- conventional N fertilizerse5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e5“Inadequate release of spring broadcast CRU was indicated by reduced grain protein concentrations relative to conventional N fertilizers”
Claim · model-written summary
CRU substantially increased the maximum safe rate of seed-placed urea.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- CRUe6
- Outcome
- maximum safe rate of seed-placed ureae6
- Direction
- increasede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e6“CRU substantially increased the maximum safe rate of seed-placed urea”
Claim · model-written summary
CRU provided minimal benefits to N response relative to side-banded urea.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- CRUe6
- Outcome
- benefits to N responsee7
- Direction
- minimale7
- Comparator
- side-banded ureae7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e6“CRU substantially increased the maximum safe rate of seed-placed urea”
e7“provided minimal benefits to N response relative to side-banded urea”
Claim · model-written summary
Broadcast in early spring, CRU was less effective than conventional N fertilizers.
- Taxon
- winter wheatTriticum aestivumt0
- Treatment
- broadcast in early springe7
- Outcome
- effectivee7
- Direction
- lesse7
- Comparator
- conventional N fertilizerse7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Controlled-release urea for winter wheat in southern Alberta”
e7“was less effective than conventional N fertilizers when broadcast in early spring”
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