Abstract
A wheat crop was grown on a nitrogen-deficient sandy soil. Urea was supplied at rates of 0 (N0), 56 (N1), and 336 (N2) kg nitrogen/ha. In general, the relative growth rate (R) decreased with time. During the first half of the growing season R for N2 > N1 >> N0, but in August deficient plants recovered rapidly. The recovery was associated with the emergence of the second tiller, an increase in net assimilation rate and nitrogen uptake, and a decrease in nitrogen stress. There was no evidence that the recovery was due to an increase in mineralization of soil nitrogen. Nitrogen stress in treatment N0 decreased from 48% in July to 14% in September. By contrast, stress in treatment N1 increased rapidly from 6 to 23% during July and fell to 5% by September. Flower initiation in N0 plants was delayed 14 days and ear emergence was delayed 8 days compared with N1 plants. The grain yields of N0 and N1 plants were 30 and 60% respectively of those of N2 plants. The decrease was due mainly to differences in the number of heads per sq metre, although nitrogen deficiency also reduced the number of grains per head and the weight per grain. The duration of photosynthetic activity after anthesis was not affected by nitrogen treatments. Harvest index was highest on N0 treatment and similar on N1 and N2 treatments.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 16
Claim · model-written summary
Relative growth rate generally declined over time.
- Taxon
- wheat crop
Triticum aestivumt0 - Outcome
- relative growth ratee0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In general, the relative growth rate (R) decreased with time.”
t0“wheat crop”
Claim · model-written summary
Early-season relative growth rate ranked N2 above N1 and N0.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N2e0
- Outcome
- Re0
- Comparator
- N1 >> N0e0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“During the first half of the growing season R for N2 > N1 >> N0, but in August deficient plants recovered rapidly.”
t0“wheat crop”
Claim · model-written summary
Deficient plants recovered rapidly in August.
- Taxon
- wheat cropTriticum aestivumt0
- Outcome
- deficient plants recovered rapidlye0
- Qualifier
- in Auguste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“in August deficient plants recovered rapidly.”
t0“wheat crop”
Claim · model-written summary
Recovery was associated with second tiller emergence, greater net assimilation and nitrogen uptake, and lower nitrogen stress.
- Taxon
- wheat cropTriticum aestivumt0
- Organ / stage
- second tillere0
- Outcome
- recoverye0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The recovery was associated with the emergence of the second tiller, an increase in net assimilation rate and nitrogen uptake, and a decrease in nitrogen stress.”
t0“wheat crop”
Claim · model-written summary
There was no evidence that greater soil nitrogen mineralization caused recovery.
- Taxon
- wheat cropTriticum aestivumt0
- Outcome
- recoverye0
- Qualifier
- increase in mineralization of soil nitrogene0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was no evidence that the recovery was due to an increase in mineralization of soil nitrogen.”
t0“wheat crop”
Claim · model-written summary
Nitrogen stress under N0 fell from 48% in July to 14% in September.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N0e0
- Outcome
- Nitrogen stresse0
- Direction
- decreasede0
- Value
- 48% in July to 14% in Septembere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Nitrogen stress in treatment N0 decreased from 48% in July to 14% in September.”
t0“wheat crop”
Claim · model-written summary
Stress under N1 rose from 6 to 23% in July before falling to 5% in September.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N1e0
- Outcome
- stresse0
- Direction
- increased rapidlye0
- Value
- 6 to 23% during Julye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“stress in treatment N1 increased rapidly from 6 to 23% during July and fell to 5% by September.”
t0“wheat crop”
Claim · model-written summary
N0 delayed flower initiation 14 days compared with N1.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N0e0
- Outcome
- Flower initiatione0
- Direction
- delayede0
- Value
- 14 dayse0
- Comparator
- N1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Flower initiation in N0 plants was delayed 14 days and ear emergence was delayed 8 days compared with N1 plants.”
t0“wheat crop”
Claim · model-written summary
N0 delayed ear emergence 8 days relative to N1.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N0e0
- Outcome
- ear emergencee0
- Direction
- delayede0
- Value
- 8 dayse0
- Comparator
- N1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Flower initiation in N0 plants was delayed 14 days and ear emergence was delayed 8 days compared with N1 plants.”
t0“wheat crop”
Claim · model-written summary
N0 grain yield was 30% of N2 grain yield.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The grain yields of N0 and N1 plants were 30 and 60% respectively of those of N2 plants.”
t0“wheat crop”
Claim · model-written summary
N1 grain yield was 60% of N2 grain yield.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The grain yields of N0 and N1 plants were 30 and 60% respectively of those of N2 plants.”
t0“wheat crop”
Claim · model-written summary
Yield decline was mainly attributable to heads per square metre.
- Taxon
- wheat cropTriticum aestivumt0
- Outcome
- decreasee0
- Qualifier
- differences in the number of heads per sq metree0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The decrease was due mainly to differences in the number of heads per sq metre”
t0“wheat crop”
Claim · model-written summary
Nitrogen deficiency reduced grains per head.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- nitrogen deficiencye0
- Outcome
- number of grains per heade0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrogen deficiency also reduced the number of grains per head and the weight per grain.”
t0“wheat crop”
Claim · model-written summary
Nitrogen deficiency reduced weight per grain.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- nitrogen deficiencye0
- Outcome
- weight per graine0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“nitrogen deficiency also reduced the number of grains per head and the weight per grain.”
t0“wheat crop”
Claim · model-written summary
Nitrogen treatments did not affect duration of photosynthetic activity after anthesis.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- nitrogen treatmentse0
- Outcome
- duration of photosynthetic activity after anthesise0
- Direction
- not affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The duration of photosynthetic activity after anthesis was not affected by nitrogen treatments.”
t0“wheat crop”
Claim · model-written summary
Harvest index was highest under N0 and similar under N1 and N2.
- Taxon
- wheat cropTriticum aestivumt0
- Treatment
- N0e0
- Outcome
- Harvest indexe0
- Direction
- higheste0
- Comparator
- N1 and N2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Harvest index was highest on N0 treatment and similar on N1 and N2 treatments.”
t0“wheat crop”
The same questions in other papers
nitrogen · physiology: photosynthesis · Triticum aestivum (wheat)Positive and negative results
21 papers in the same direction as this paper · 98 in the opposite direction
- positive
- positive
- positive
116 papers more in this group
See all 120 papers →nitrogen · yield · Triticum aestivum (wheat)Positive and negative results
1,736 papers in the same direction as this paper · 285 in the opposite direction · 39 reporting no difference from an alternative
This paper is about lacking the nutrient, so it counts the other way round here.
- positive
- negative
- negative
2,057 papers more in this group
See all 2,061 papers →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.