Abstract
Controlled-release urea (CRU) has better characteristics than conventional urea for synchronizing nitrogen (N) release with plant uptake. Understanding the effects of CRU on crop yield and N use efficiency (NUE) has long been the key to evaluate the performance of CRU. A long-term experiment over five consecutive years was conducted in Changsha, Hunan Province, China, to investigate the effects of polyethylene-coated urea with a 90-d release period on the yield and NUE of double rice (early and late crops are grown in the same year), the amount of residual soil mineral N and the soil–plant N balance, as well as on the economic benefits. Four N fertilizer treatments including CK (no N fertilizer), U (conventional urea), CRU1 (polyethylene-coated urea with equal N application rate to U) and CRU2 (20% reduction in N application rate of CRU1) were established. The results indicated that CRU1 application increased the yield and NUE of double rice by 11.0 and 13.5%, respectively, compared with U. Higher yield and NUE of late rice were found than in early rice in CRU treatments. Compared with conventional U, the yield and NUE of early rice in the CRU1 treatment were increased by 6.0 and 10.2%, respectively, and those of late rice were increased by 15.4 and 13.8%, respectively. There was no significant difference between CRU1 and CRU2 in double rice yield. Furthermore, CRU treatments (including CRU1 and CRU2) had higher apparent residual Nmin rate (ARNR) and apparent N recovery rate (ANRR), but lower apparent N loss (NS) than the conventional U treatment. Concentrations of NH4+-N and NO3–-N were greater in the surface soil (0–20 cm) and lower in the deeper soil layer (40–60 cm) with CRU treatments than in the U treatment after harvest. Moreover, CRU application produced a greater economic benefit than conventional U application. In general, CRU outperformed U fertilizer in terms of rice yield, NUE, soil–plant N balance, economic benefit, and CRU2 provided greater comprehensive benefits than CRU1. It is suggested that CRU application is beneficial for solving N management challenges in the production of rice.
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Claims 17
Claim · model-written summary
CRU1 increased double rice yield by 11.0% relative to U.
Verbatim
e0“CRU1 application increased the yield and NUE of double rice by 11.0 and 13.5%, respectively, compared with U”
Claim · model-written summary
CRU1 increased double rice NUE by 13.5% relative to U.
Verbatim
e0“CRU1 application increased the yield and NUE of double rice by 11.0 and 13.5%, respectively, compared with U”
Claim · model-written summary
Late rice had higher yield than early rice with CRU treatments.
- Taxon
- rice
Oryza sativae0 - Treatment
- CRU treatmentse0
- Outcome
- yielde0
- Direction
- Highere0
- Comparator
- early ricee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Higher yield and NUE of late rice were found than in early rice in CRU treatments”
Claim · model-written summary
Late rice had higher NUE than early rice with CRU treatments.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Higher yield and NUE of late rice were found than in early rice in CRU treatments”
Claim · model-written summary
CRU1 increased early rice yield by 6.0% versus U.
Verbatim
e0“Compared with conventional U, the yield and NUE of early rice in the CRU1 treatment were increased by 6.0 and 10.2%, respectively”
Claim · model-written summary
CRU1 increased early rice NUE by 10.2% versus U.
Verbatim
e0“Compared with conventional U, the yield and NUE of early rice in the CRU1 treatment were increased by 6.0 and 10.2%, respectively”
Claim · model-written summary
CRU1 increased late rice yield by 15.4% versus U.
Not reportedTreatmentComparator
Verbatim
e0“those of late rice were increased by 15.4 and 13.8%, respectively”
Claim · model-written summary
CRU1 increased late rice NUE by 13.8% versus U.
Not reportedTreatmentComparator
Verbatim
e0“those of late rice were increased by 15.4 and 13.8%, respectively”
Claim · model-written summary
Double rice yield did not differ significantly between CRU1 and CRU2.
Verbatim
e0“There was no significant difference between CRU1 and CRU2 in double rice yield”
Claim · model-written summary
CRU treatments increased apparent residual mineral N rate versus U.
- Treatment
- CRU treatmentse0
- Outcome
- apparent residual Nmin rate (ARNR)e0
- Direction
- highere0
- Comparator
- conventional U treatmente0
Not reportedTaxon
Verbatim
e0“CRU treatments (including CRU1 and CRU2) had higher apparent residual Nmin rate (ARNR) and apparent N recovery rate (ANRR), but lower apparent N loss (NS) than the conventional U treatment”
Claim · model-written summary
CRU treatments increased apparent N recovery rate versus U.
- Treatment
- CRU treatmentse0
- Outcome
- apparent N recovery rate (ANRR)e0
- Direction
- highere0
- Comparator
- conventional U treatmente0
Not reportedTaxon
Verbatim
e0“CRU treatments (including CRU1 and CRU2) had higher apparent residual Nmin rate (ARNR) and apparent N recovery rate (ANRR), but lower apparent N loss (NS) than the conventional U treatment”
Claim · model-written summary
CRU treatments lowered apparent N loss versus U.
- Treatment
- CRU treatmentse0
- Outcome
- apparent N loss (NS)e0
- Direction
- lowere0
- Comparator
- conventional U treatmente0
Not reportedTaxon
Verbatim
e0“CRU treatments (including CRU1 and CRU2) had higher apparent residual Nmin rate (ARNR) and apparent N recovery rate (ANRR), but lower apparent N loss (NS) than the conventional U treatment”
Claim · model-written summary
CRU increased postharvest NH4+-N and NO3–-N in surface soil versus U.
- Treatment
- CRU treatmentse0
- Outcome
- Concentrations of NH4+-N and NO3–-Ne0
- Direction
- greatere0
- Qualifier
- surface soil (0–20 cm)e0
- Comparator
- U treatmente0
Not reportedTaxon
Verbatim
e0“Concentrations of NH4+-N and NO3–-N were greater in the surface soil (0–20 cm) and lower in the deeper soil layer (40–60 cm) with CRU treatments than in the U treatment after harvest”
Claim · model-written summary
CRU lowered postharvest NH4+-N and NO3–-N in deeper soil versus U.
- Treatment
- CRU treatmentse0
- Outcome
- Concentrations of NH4+-N and NO3–-Ne0
- Direction
- lowere0
- Qualifier
- deeper soil layer (40–60 cm)e0
- Comparator
- U treatmente0
Not reportedTaxon
Verbatim
e0“Concentrations of NH4+-N and NO3–-N were greater in the surface soil (0–20 cm) and lower in the deeper soil layer (40–60 cm) with CRU treatments than in the U treatment after harvest”
Claim · model-written summary
CRU provided greater economic benefit than conventional U.
- Treatment
- CRU applicatione0
- Outcome
- economic benefite0
- Direction
- greatere0
- Comparator
- conventional U applicatione0
Not reportedTaxon
Verbatim
e0“CRU application produced a greater economic benefit than conventional U application”
Claim · model-written summary
CRU2 provided greater comprehensive benefits than CRU1.
Not reportedTaxon
Verbatim
e0“CRU2 provided greater comprehensive benefits than CRU1”
Claim · model-written summary
Authors recommend CRU for rice nitrogen management.
- Taxon
- riceOryza sativae0
- Outcome
- CRU applicatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CRU application is beneficial for solving N management challenges in the production of rice”
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