Abstract
Effective nitrogen (N) management in agriculture is vital to optimize crop growth and yield while minimizing environmental impact. Conventional nitrogen (N) sources, such as urea, have limitations in promoting growth and reducing N leaching. A two-year field experiment was carried out to investigate the effects of calcium cyanamide (CaCN2) as a slow-release N source on short-day onion growth, yield, and N use efficiency (NUE). Six types of N sources were administered: (i) an initial application of 80 kg ha−1 N in the form of CaCN2 before planting; (ii) an initial application of 80 kg ha−1 N in the form of CaCN2 before planting, followed by a topdressing of 50 kg ha−1 N in the form of limestone ammonium nitrate (LAN); (iii) an initial application of 80 kg ha−1 N in the form of CaCN2 before planting, followed by a topdressing of 50 kg ha−1 N in the form of urea; (iv) an initial application of 80 kg ha−1 N in the form of LAN before planting, followed by a topdressing of 50 kg ha−1 N in the form of LAN; (v) an initial application of 80 kg ha−1 N in the form of urea before planting, followed by a topdressing of 50 kg ha−1 N in the form of urea; and (vi) control (0 kg ha−1 N). Preplant CaCN2 (80 kg ha−1 N) outperformed the standard fertilizers used in onion as an N source (urea and LAN) by improving growth and yield, and reducing N leaching. Preplant CaCN2 topdressed with either LAN or urea led to a significant increase in plant growth and total yield compared to using LAN or urea alone. The application of CaCN2, followed by topdressing with either LAN or urea, decreased onion bolting by 1.6% and 1.83%, respectively, compared to the control. The study suggests that applying LAN or urea as a topdressing to preplant CaCN2 enhances N utilization efficiency, leading to increased onion bulb yield and quality while reducing N leaching. This approach can help mitigate farm-level environmental pollution and provide valuable insights for improving onion production and sustainable agriculture practices in South Africa.
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Claims 7
Claim · model-written summary
Preplant CaCN2 improved onion growth compared with urea and LAN.
- Taxon
- onion
Allium cepae0 - Treatment
- Preplant CaCN2 (80 kg ha−1 N)e0
- Outcome
- growthe0
- Direction
- improvinge0
- Comparator
- urea and LANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Preplant CaCN2 (80 kg ha−1 N) outperformed the standard fertilizers used in onion as an N source (urea and LAN) by improving growth and yield, and reducing N leaching.”
Claim · model-written summary
Preplant CaCN2 improved onion yield compared with urea and LAN.
- Taxon
- onionAllium cepae0
- Treatment
- Preplant CaCN2 (80 kg ha−1 N)e0
- Outcome
- yielde0
- Direction
- improvinge0
- Comparator
- urea and LANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Preplant CaCN2 (80 kg ha−1 N) outperformed the standard fertilizers used in onion as an N source (urea and LAN) by improving growth and yield, and reducing N leaching.”
Claim · model-written summary
Preplant CaCN2 reduced nitrogen leaching relative to urea and LAN.
- Taxon
- onionAllium cepae0
- Treatment
- Preplant CaCN2 (80 kg ha−1 N)e0
- Outcome
- N leachinge0
- Direction
- reducinge0
- Comparator
- urea and LANe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Preplant CaCN2 (80 kg ha−1 N) outperformed the standard fertilizers used in onion as an N source (urea and LAN) by improving growth and yield, and reducing N leaching.”
Claim · model-written summary
CaCN2 followed by LAN increased onion plant growth relative to LAN alone.
- Treatment
- Preplant CaCN2 topdressed with either LAN or ureae0
- Outcome
- plant growth and total yielde0
- Direction
- increasee0
- Comparator
- LAN or urea alonee0
Not reportedTaxon
Verbatim
e0“Preplant CaCN2 topdressed with either LAN or urea led to a significant increase in plant growth and total yield compared to using LAN or urea alone.”
Claim · model-written summary
CaCN2 followed by LAN decreased onion bolting by 1.6% relative to control.
- Taxon
- onionAllium cepae0
- Treatment
- CaCN2, followed by topdressing with either LAN or ureae0
- Outcome
- onion boltinge0
- Direction
- decreasede0
- Value
- 1.6%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of CaCN2, followed by topdressing with either LAN or urea, decreased onion bolting by 1.6% and 1.83%, respectively, compared to the control.”
Claim · model-written summary
CaCN2 followed by urea decreased onion bolting by 1.83% relative to control.
- Taxon
- onionAllium cepae0
- Treatment
- CaCN2, followed by topdressing with either LAN or ureae0
- Outcome
- onion boltinge0
- Direction
- decreasede0
- Value
- 1.83%e0
- Comparator
- controle0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The application of CaCN2, followed by topdressing with either LAN or urea, decreased onion bolting by 1.6% and 1.83%, respectively, compared to the control.”
Claim · model-written summary
The authors suggest topdressing preplant CaCN2 with LAN or urea to enhance nitrogen utilization efficiency and bulb yield and quality while reducing leaching.
- Taxon
- onionAllium cepae0
- Outcome
- applying LAN or urea as a topdressing to preplant CaCN2e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The study suggests that applying LAN or urea as a topdressing to preplant CaCN2 enhances N utilization efficiency, leading to increased onion bulb yield and quality while reducing N leaching.”
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