Abstract
Abstract Controlled‐release urea (CRU) is a new type of urea, which may increase crop nitrogen (N)‐use efficiency compared with conventional urea (CU), but the conditions where it outperforms urea are not well defined. A field experiment assessing responses of plant growth and grain yield of maize to CRU and irrigation was conducted on a typical agricultural farm in Shandong, China. Five treatments of the two types of urea (75, 150 kg N ha –1 , 0 kg N ha –1 ) were applied as basal fertilizer when sowing maize, and two water treatments (W 0 and W 1 ) were used 23 d after anthesis. Net photosynthetic rate ( P N ) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU‐treated plants than in CU‐treated plants at grain filling and maturing stages. CRU significantly enhanced the maximum photochemical efficiency ( F v / F m ), PSII coefficient of photochemical fluorescence quenching ( q P ), and actual quantum yield of PSII electron transformation (Φ PSII ) but decreased the nonphotochemical quenching (NPQ). Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis. Significant positive correlations were found between cob‐leaf N concentration and P N both with and without irrigation. Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions. In conclusion, CRU as a basal application appeared to increase the N‐use efficiency for maize relative to CU especially by maintaining N supply after anthesis.
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 9
Claim · model-written summary
Both CRU and CU significantly increased photosynthetic rate, chlorophyll concentration and leaf-area index.
- Treatment
- CRU and CU applicatione0
- Outcome
- Net photosynthetic rate ( P N ) and chlorophyll concentration as well as leaf‐area index (LAI)e0
- Direction
- increasede0
Zea maysNot reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Net photosynthetic rate ( P N ) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application”
t0“maize”
Claim · model-written summary
CRU produced larger increases in those traits than CU during grain filling and maturation.
- Organ / stage
- grain filling and maturing stagese0
- Treatment
- CRUe0
- Outcome
- Net photosynthetic rate ( P N ) and chlorophyll concentration as well as leaf‐area index (LAI)e0
- Direction
- largere0
- Comparator
- CUe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Net photosynthetic rate ( P N ) and chlorophyll concentration as well as leaf‐area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU‐treated plants than in CU‐treated plants at grain filling and maturing stages.”
t0“maize”
Claim · model-written summary
CRU significantly enhanced maximum photochemical efficiency, photochemical fluorescence quenching and PSII quantum yield.
- Treatment
- CRUe0
- Outcome
- maximum photochemical efficiency ( F v / F m ), PSII coefficient of photochemical fluorescence quenching ( q P ), and actual quantum yield of PSII electron transformation (Φ PSII )e0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CRU significantly enhanced the maximum photochemical efficiency ( F v / F m ), PSII coefficient of photochemical fluorescence quenching ( q P ), and actual quantum yield of PSII electron transformation (Φ PSII )”
t0“maize”
Claim · model-written summary
CRU decreased nonphotochemical quenching.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CRU significantly enhanced the maximum photochemical efficiency ( F v / F m ), PSII coefficient of photochemical fluorescence quenching ( q P ), and actual quantum yield of PSII electron transformation (Φ PSII ) but decreased the nonphotochemical quenching (NPQ).”
t0“maize”
Claim · model-written summary
Without irrigation, CRU cob-leaf nitrogen concentration was significantly higher than CU.
- Treatment
- CRUe0
- Outcome
- Cob‐leaf N concentratione0
- Direction
- highere0
- Qualifier
- under no irrigatione0
- Comparator
- CUe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation”
t0“maize”
Claim · model-written summary
The higher cob-leaf nitrogen concentration under CRU was not significant in irrigated plants 30 days after anthesis.
- Treatment
- CRUe0
- Outcome
- Cob‐leaf N concentratione0
- Qualifier
- irrigation treatment 30 d after anthesise0
- Comparator
- CUe0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cob‐leaf N concentration of CRU‐treated plants was significantly higher than that of CU‐treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis.”
t0“maize”
Claim · model-written summary
Cob-leaf nitrogen concentration and photosynthetic rate were significantly positively correlated with and without irrigation.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Significant positive correlations were found between cob‐leaf N concentration and P N both with and without irrigation.”
t0“maize”
Claim · model-written summary
CRU significantly increased maize grain yield over CU under both irrigation conditions.
- Treatment
- CRU treatmente0
- Outcome
- Grain yielde0
- Direction
- highere0
- Qualifier
- under both irrigation conditionse0
- Comparator
- CU treatmente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions.”
Claim · model-written summary
Basal CRU appeared to improve nitrogen-use efficiency relative to CU by maintaining nitrogen supply after anthesis.
- Treatment
- CRU as a basal applicatione0
- Outcome
- N‐use efficiencye0
- Direction
- increasee0
- Qualifier
- maintaining N supply after anthesise0
- Comparator
- CUe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CRU as a basal application appeared to increase the N‐use efficiency for maize relative to CU especially by maintaining N supply after anthesis.”
The same questions in other papers
fertilization · physiology: photosynthesis · Zea mays (maize)Results differ
91 papers in the same direction as this paper · 12 in the opposite direction
- positive
- no effect
- no effect
100 papers more in this group
See all 104 papers →nitrogen · physiology: photosynthesis · Zea mays (maize)Positive and negative results
77 papers in the same direction as this paper · 18 in the opposite direction · 2 reporting no difference from an alternative
- positive
- positive
- positive
94 papers more in this group
See all 98 papers →nitrogen · nutrient: content · Zea mays (maize)Positive and negative results
402 papers in the same direction as this paper · 83 in the opposite direction · 3 reporting no difference from an alternative
- positive
- no effect
- negative
485 papers more in this group
See all 489 papers →nitrogen · growth · Zea mays (maize)Positive and negative results
618 papers in the same direction as this paper · 115 in the opposite direction · 14 reporting no difference from an alternative
- positive
- positive
- positive
744 papers more in this group
See all 748 papers →fertilization · nutrient: content · Zea mays (maize)Positive and negative results
1,025 papers in the same direction as this paper · 127 in the opposite direction · 11 reporting no difference from an alternative
- positive
- negative
- negative
1,160 papers more in this group
See all 1,164 papers →fertilization · growth · Zea mays (maize)Positive and negative results
1,195 papers in the same direction as this paper · 149 in the opposite direction · 20 reporting no difference from an alternative
- positive
- positive
- positive
1,361 papers more in this group
See all 1,365 papers →nitrogen · yield · Zea mays (maize)Positive and negative results
1,905 papers in the same direction as this paper · 234 in the opposite direction · 45 reporting no difference from an alternative
- positive
- positive
- positive
2,181 papers more in this group
See all 2,185 papers →fertilization · yield · Zea mays (maize)Positive and negative results
3,484 papers in the same direction as this paper · 338 in the opposite direction · 85 reporting no difference from an alternative
- positive
- positive
- positive
3,904 papers more in this group
See all 3,908 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.