Abstract
Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields, but inappropriate application methods and excessive amounts lead to low N use efficiency and high N losses through leaching. To investigate the effects of controlled‐release urea (CRU) on crop yield and soil fertility, a field experiment was conducted from 2012 to 2014 in China. The 100% (180 kg ha −1 ) and 70% (126 kg ha −1 ) of the local practice N rates with CRU and urea were used. The results revealed that the release curves of CRU in the natural field corresponded well to the N requirements of wheat and corn plants, and a positive linear correlation was observed between release rates and days after buried in soil. Consequently, the CRU treatments achieved significantly higher wheat and corn yield by 8 to 12% and 9 to 11%, respectively, compared with urea treatments at the same N rate. Reducing N rate of CRU by 30% produced the same yield as with the 100% N rate of urea. The agronomic nitrogen use efficiency (NUE) was significantly increased and the leaching of soil N was reduced by CRU. The acidification rates and leaching of exchangeable Ca 2+ , K + , Na + contents were reduced, base saturation and available P improved by application of CRU compared with urea. Therefore, the results suggested that a 30% decrease of CRU in the recommended application rate of N, can be an effective measure to save consumption input of N fertilizer. Core Ideas Nitrogen release rates of controlled‐release urea in field condition corresponded well to the N uptake of crop plants. A 30% decrease in the application rate of N is possible with controlled‐release urea compared to urea. The application of controlled‐release urea increased crop yield, N use efficiency, net farm profit, and soil fertility.
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Claims 11
Claim · model-written summary
Controlled-release urea treatments gave significantly higher wheat yield by 8 to 12% than urea at the same N rate.
- Taxon
- wheat
Triticum aestivume2 - Treatment
- CRU treatmentse2
- Outcome
- yielde2
- Direction
- highere2
- Value
- 8 to 12%e2
- Comparator
- urea treatments at the same N ratee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“the CRU treatments achieved significantly higher wheat and corn yield by 8 to 12% and 9 to 11%, respectively, compared with urea treatments at the same N rate”
Claim · model-written summary
Controlled-release urea treatments gave significantly higher corn yield by 9 to 11% than urea at the same N rate.
- Taxon
- corn
Zea mays subsp. mayse2 - Treatment
- CRU treatmentse2
- Outcome
- yielde2
- Direction
- highere2
- Value
- 9 to 11%e2
- Comparator
- urea treatments at the same N ratee2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“the CRU treatments achieved significantly higher wheat and corn yield by 8 to 12% and 9 to 11%, respectively, compared with urea treatments at the same N rate”
Claim · model-written summary
Reducing the CRU N rate by 30% gave the same yield as the 100% N rate of urea.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivum
Zea mayse1 - Treatment
- Reducing N rate of CRU by 30%e3
- Outcome
- yielde3
- Direction
- samee3
- Comparator
- 100% N rate of ureae3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e3“Reducing N rate of CRU by 30% produced the same yield as with the 100% N rate of urea”
Claim · model-written summary
Controlled-release urea release curves in the natural field corresponded well to the N requirements of wheat and corn.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Outcome
- release curves of CRUe4
- Qualifier
- corresponded well to the N requirementse4
- Setting
- natural fielde4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e4“the release curves of CRU in the natural field corresponded well to the N requirements of wheat and corn plants”
Claim · model-written summary
Controlled-release urea release rates were positively linearly correlated with days after burial in soil.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Outcome
- release ratese5
- Qualifier
- positive linear correlatione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e5“a positive linear correlation was observed between release rates and days after buried in soil”
Claim · model-written summary
Agronomic nitrogen use efficiency was significantly increased by controlled-release urea compared with urea.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Treatment
- CRUe6
- Outcome
- agronomic nitrogen use efficiency (NUE)e6
- Direction
- increasede6
- Comparator
- ureae7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e6“The agronomic nitrogen use efficiency (NUE) was significantly increased and the leaching of soil N was reduced by CRU”
e7“application of CRU compared with urea”
Claim · model-written summary
Controlled-release urea reduced soil N leaching.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Treatment
- CRUe6
- Outcome
- leaching of soil Ne6
- Direction
- reducede6
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e6“The agronomic nitrogen use efficiency (NUE) was significantly increased and the leaching of soil N was reduced by CRU”
Claim · model-written summary
Controlled-release urea reduced soil acidification rates compared with urea.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Treatment
- CRUe7
- Outcome
- acidification ratese2
- Direction
- reducede2
- Comparator
- ureae7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“The acidification rates and leaching of exchangeable Ca 2+ , K + , Na + contents were reduced”
e7“application of CRU compared with urea”
Claim · model-written summary
Controlled-release urea reduced leaching of exchangeable Ca, K and Na contents compared with urea.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Treatment
- CRUe7
- Outcome
- leaching of exchangeable Ca 2+ , K + , Na + contentse2
- Direction
- reducede2
- Comparator
- ureae7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“The acidification rates and leaching of exchangeable Ca 2+ , K + , Na + contents were reduced”
e7“application of CRU compared with urea”
Claim · model-written summary
Controlled-release urea improved base saturation and available P compared with urea.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Treatment
- CRUe2
- Outcome
- base saturation and available Pe2
- Direction
- improvede2
- Comparator
- ureae2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“base saturation and available P improved by application of CRU compared with urea”
Claim · model-written summary
A 30% decrease of CRU in the recommended N rate can be an effective measure to save N fertilizer input.
- Taxon
- wheat ( Triticum aestivum L.) and corn ( Zea mays L.)Triticum aestivumZea mayse1
- Outcome
- consumption input of N fertilizere2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“Nitrogen fertilizer is important for improving wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields”
e2“can be an effective measure to save consumption input of N fertilizer”
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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.