Paper · 2025 · Agronomy

One-Time Application of Polymer-Coated Urea Increased Rice Yield and Plant Nitrogen Uptake by Optimizing Root Morphological and Physiological Traits

Junlin Zhu; Song Chen; Chunmei Xu; et al.

20
claims
37
verbatim quotes
4
citations
2
research areas
✓
Open access · cc-by

Abstract

Previous studies have shown that a one-time application of polymer-coated urea (PCU) can increase rice yield and nitrogen (N) uptake. However, the connection between rice root morphology and physiological traits and grain yield and N absorption has still not been well understood. The objective of this study was to explore whether one-time application of PCU could enhance shoot growth, improve plant physiological activity, and ultimately boost rice yield and NUE by optimizing root morphological and physiological traits. In this study, a super-large-panicle indica-japonica hybrid rice variety, Yongyou1540, was cultivated under three N treatments during 2022 and 2023: (1) 0N, throughout the entire growth period, no N fertilizer was applied; (2) LFP, local farmers’ N management practices were followed, using urea as the N source, and N fertilizer management was carried out according to the local farmers’ customary fertilization practices; and (3) PCU, a one-time application of PCU was performed at one day before transplanting. PCU is a controlled-release fertilizer in which urea granules are coated with a synthetic polymer layer; it has been widely used in rice cultivation. In both LFP and PCU treatments, N was applied at a rate of 200 kg N ha−1. PCU is a type of controlled-release fertilizer in which urea granules are coated with a layer of synthetic polymer. Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading. Additionally, PCU enhanced root oxidative activity (ROA) and increased zeatin and zeatin riboside (Z+ZR) content in both roots and root bleeding sap at the middle and late grain-filling stages. Furthermore, PCU markedly increased the flag-leaf net photosynthetic rate, Z+ZR content in leaves, and activities of key enzymes involved in sucrose-to-starch conversion in grains during the middle and late grain-filling stages. Correlation analysis indicated that root and shoot biomass growth rate showed a significant positive correlation before heading, and that root biomass reduction rate was significantly negatively correlated with shoot biomass growth rate after heading. ROA and Z+ZR content in both roots and root bleeding sap were significantly associated with flag-leaf photosynthetic rate, Z+ZR content in leaves, and the activities of key enzymes involved in the sucrose-to-starch conversion in grains. On average, PCU increased rice yield by 10.0% and agronomic NUE by 46.2%, compared to LFP. These findings suggest that PCU could optimize root morphological and physiological traits, and thereby promote shoot growth, enhance physiological activity, and ultimately increase both rice yield and NUE. Further research could also investigate the potential for combining PCU with other agronomic practices to enhance both rice yield and NUE.

Abstract from the paper’s OpenAlex record; open copy licensed cc-by. 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 20

Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved deep-root proportion compared with LFP.

Treatment
PCUe0
Outcome
deep-root proportione0
Direction
increasede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved specific root length (SRL) compared with LFP.

Treatment
PCUe0
Outcome
specific root length (SRL)e0
Direction
increasede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved root length compared with LFP.

Treatment
PCUe0
Outcome
root lengthe0
Direction
increasede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved root length density compared with LFP.

Treatment
PCUe0
Outcome
root length densitye0
Direction
increasede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved root biomass growth rate compared with LFP.

Treatment
PCUe0
Outcome
root biomass growth ratee0
Direction
increasede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

PCU improved reduction rate compared with LFP.

Treatment
PCUe0
Outcome
reduction ratee0
Direction
reducede0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Compared to LFP, PCU significantly improved several root morphological traits, including increased deep-root proportion and specific root length (SRL), throughout the entire growth period; increased root length and root length density at heading and maturity; and increased root biomass growth rate from jointing to heading and reduced reduction rate after heading.”

✓ located verbatim in the source · abstract, characters 1379–1744 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU enhanced root oxidative activity.

Treatment
PCUe0
Outcome
root oxidative activity (ROA)e0
Direction
enhancede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Additionally, PCU enhanced root oxidative activity (ROA) and increased zeatin and zeatin riboside (Z+ZR) content in both roots and root bleeding sap at the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1745–1938 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased Z+ZR content in roots.

Organ / stage
rootse0
Treatment
PCUe0
Outcome
zeatin and zeatin riboside (Z+ZR) contente0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Additionally, PCU enhanced root oxidative activity (ROA) and increased zeatin and zeatin riboside (Z+ZR) content in both roots and root bleeding sap at the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1745–1938 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased Z+ZR content in root bleeding sap.

Organ / stage
root bleeding sape0
Treatment
PCUe0
Outcome
zeatin and zeatin riboside (Z+ZR) contente0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Additionally, PCU enhanced root oxidative activity (ROA) and increased zeatin and zeatin riboside (Z+ZR) content in both roots and root bleeding sap at the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1745–1938 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased flag-leaf net photosynthetic rate.

Treatment
PCUe0
Outcome
flag-leaf net photosynthetic ratee0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Furthermore, PCU markedly increased the flag-leaf net photosynthetic rate, Z+ZR content in leaves, and activities of key enzymes involved in sucrose-to-starch conversion in grains during the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1939–2167 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased Z+ZR content in leaves.

Treatment
PCUe0
Outcome
Z+ZR content in leavese0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Furthermore, PCU markedly increased the flag-leaf net photosynthetic rate, Z+ZR content in leaves, and activities of key enzymes involved in sucrose-to-starch conversion in grains during the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1939–2167 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased activities of key enzymes involved in sucrose-to-starch conversion in grains.

Treatment
PCUe0
Outcome
activities of key enzymes involved in sucrose-to-starch conversion in grainse0
Direction
increasede0

Not reportedComparator

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Furthermore, PCU markedly increased the flag-leaf net photosynthetic rate, Z+ZR content in leaves, and activities of key enzymes involved in sucrose-to-starch conversion in grains during the middle and late grain-filling stages.”

✓ located verbatim in the source · abstract, characters 1939–2167 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Associationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Root and shoot biomass growth rates correlated positively before heading.

Organ / stage
roote0
Outcome
shoot biomass growth ratee0
Direction
positive correlatione0
Qualifier
before headinge0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Correlation analysis indicated that root and shoot biomass growth rate showed a significant positive correlation before heading, and that root biomass reduction rate was significantly negatively correlated with shoot biomass growth rate after heading.”

✓ located verbatim in the source · abstract, characters 2168–2419 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Associationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Root biomass reduction rate correlated negatively with shoot growth rate after heading.

Organ / stage
roote0
Outcome
shoot biomass growth ratee0
Direction
negatively correlatede0
Qualifier
after headinge0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“Correlation analysis indicated that root and shoot biomass growth rate showed a significant positive correlation before heading, and that root biomass reduction rate was significantly negatively correlated with shoot biomass growth rate after heading.”

✓ located verbatim in the source · abstract, characters 2168–2419 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Associationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Root ROA and Z+ZR content were associated with flag-leaf photosynthetic rate.

Organ / stage
rootse0
Outcome
flag-leaf photosynthetic ratee0
Qualifier
ROA and Z+ZR contente0

Not reportedDirection

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“ROA and Z+ZR content in both roots and root bleeding sap were significantly associated with flag-leaf photosynthetic rate, Z+ZR content in leaves, and the activities of key enzymes involved in the sucrose-to-starch conversion in grains.”

✓ located verbatim in the source · abstract, characters 2420–2656 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Associationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Root ROA and Z+ZR content were associated with Z+ZR content in leaves.

Organ / stage
rootse0
Outcome
Z+ZR content in leavese0
Qualifier
ROA and Z+ZR contente0

Not reportedDirection

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“ROA and Z+ZR content in both roots and root bleeding sap were significantly associated with flag-leaf photosynthetic rate, Z+ZR content in leaves, and the activities of key enzymes involved in the sucrose-to-starch conversion in grains.”

✓ located verbatim in the source · abstract, characters 2420–2656 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Associationobservedoriginal resultsignificant (as stated)measured

Claim · model-written summary

Root ROA and Z+ZR content were associated with activities of key enzymes involved in the sucrose-to-starch conversion in grains.

Organ / stage
rootse0
Outcome
activities of key enzymes involved in the sucrose-to-starch conversion in grainse0
Qualifier
ROA and Z+ZR contente0

Not reportedDirection

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“ROA and Z+ZR content in both roots and root bleeding sap were significantly associated with flag-leaf photosynthetic rate, Z+ZR content in leaves, and the activities of key enzymes involved in the sucrose-to-starch conversion in grains.”

✓ located verbatim in the source · abstract, characters 2420–2656 · show in text ↑
t0

“Rice”

✓ located verbatim in the source · title, characters 54–58 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased rice yield by 10.0% versus LFP.

Treatment
PCUe0
Outcome
rice yielde0
Direction
increasede0
Value
10.0%e0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“On average, PCU increased rice yield by 10.0% and agronomic NUE by 46.2%, compared to LFP.”

✓ located verbatim in the source · abstract, characters 2657–2747 · show in text ↑
Intervention effectobservedoriginal resultpositivemeasured

Claim · model-written summary

PCU increased agronomic NUE by 46.2% versus LFP.

Treatment
PCUe0
Outcome
agronomic NUEe0
Direction
increasede0
Value
46.2%e0
Comparator
LFPe0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“On average, PCU increased rice yield by 10.0% and agronomic NUE by 46.2%, compared to LFP.”

✓ located verbatim in the source · abstract, characters 2657–2747 · show in text ↑
Mechanismauthor interpretationoriginal resultmeasured

Claim · model-written summary

Authors infer PCU optimizes roots to promote shoots, physiology, yield and NUE.

Treatment
PCUe0
Outcome
increase both rice yield and NUEe0
Qualifier
root morphological and physiological traitse0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Oryza sativa
Oryza sativa · Taxon · picture from its Wikimedia Commons categoryDesmanthus4food · CC BY-SA 3.0 us · Wikimedia Commons ↗

Verbatim

e0

“These findings suggest that PCU could optimize root morphological and physiological traits, and thereby promote shoot growth, enhance physiological activity, and ultimately increase both rice yield and NUE.”

✓ located verbatim in the source · abstract, characters 2748–2954 · show in text ↑

nitrogen · physiology: hormones · Oryza sativa (rice)Positive and negative results

14 papers: 12 positive, 2 negative or no effect

11 papers in the same direction as this paper · 2 in the opposite direction

  1. negative
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511 papers: 402 positive, 109 negative or no effect

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2,045 papers: 1,803 positive, 242 negative or no effect

1,802 papers in the same direction as this paper · 193 in the opposite direction · 49 reporting no difference from an alternative

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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.