Abstract
Improvement of N fertilizer recovery efficiency (NRE) is necessary to reduce excess N entering the environment and to increase economic returns. A 2‐yr field trial was established in 2005 in Northeast Missouri to determine the effects of conventional and slow‐release N fertilizer sources and landscape position (summit, sideslope, and low‐lying) on crop growth and NRE in corn ( Zea mays L.) in a claypan soil. Nitrogen fertilizer treatments at 168 kg N ha −1 consisted of pre‐plant applied and incorporated polymer‐coated urea (PCU), urea, 50% PCU/50% urea mix by weight, anhydrous ammonia (AA), and a nontreated control. Gravimetric soil water content data in 2005 and 2006 indicated that the low‐lying position was often wetter than the summit and sideslope positions. Anhydrous ammonia and PCU treatments increased grain yield 1470 to 1810 kg ha −1 over urea in the low‐lying position in 2005 and 2006. Corresponding increases in plant N uptake and NRE were observed in the low‐lying position in 2005 with use of PCU and AA compared to urea, but not in 2006. Based on the grain yield results in this research and different fertilizer cost and crop prices, gross profit differences for use of PCU and preplant‐applied AA compared with urea in the low‐lying position could range from $50 to $642 ha −1 . These results demonstrate that targeted use of different N fertilizer sources in claypan landscapes may increase grain yields and profitability.
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Claims 7
Claim · model-written summary
The low-lying position was often wetter than summit and sideslope positions in 2005 and 2006.
Not reportedTaxon
Verbatim
e0“Gravimetric soil water content data in 2005 and 2006 indicated that the low‐lying position was often wetter than the summit and sideslope positions”
Claim · model-written summary
Anhydrous ammonia increased corn grain yield over urea in the low-lying position in 2005 and 2006.
- Treatment
- Anhydrous ammoniae0
- Outcome
- grain yielde0
- Direction
- increasede0
- Value
- 1470 to 1810 kg ha −1e0
- Comparator
- ureae0
- Setting
- low‐lying positione0
Not reportedTaxon
Verbatim
e0“Anhydrous ammonia and PCU treatments increased grain yield 1470 to 1810 kg ha −1 over urea in the low‐lying position in 2005 and 2006”
t0“Corn”
Claim · model-written summary
PCU increased corn grain yield over urea in the low-lying position in 2005 and 2006.
- Taxon
- Corn
Zea mays subsp. mayst0 - Treatment
- PCUe0
- Outcome
- grain yielde0
- Direction
- increasede0
- Value
- 1470 to 1810 kg ha −1e0
- Comparator
- ureae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Anhydrous ammonia and PCU treatments increased grain yield 1470 to 1810 kg ha −1 over urea in the low‐lying position in 2005 and 2006”
t0“Corn”
Claim · model-written summary
PCU increased plant N uptake and NRE relative to urea in the low-lying position in 2005 but not 2006.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- PCUe0
- Outcome
- plant N uptake and NREe0
- Direction
- increasese0
- Comparator
- ureae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Corresponding increases in plant N uptake and NRE were observed in the low‐lying position in 2005 with use of PCU and AA compared to urea, but not in 2006”
t0“Corn”
Claim · model-written summary
AA increased plant N uptake and NRE relative to urea in the low-lying position in 2005 but not 2006.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- AAe0
- Outcome
- plant N uptake and NREe0
- Direction
- increasese0
- Comparator
- ureae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Corresponding increases in plant N uptake and NRE were observed in the low‐lying position in 2005 with use of PCU and AA compared to urea, but not in 2006”
t0“Corn”
Claim · model-written summary
Gross profit differences for PCU and preplant AA versus urea in the low-lying position could range from $50 to $642 per hectare.
Not reportedTaxon
Verbatim
e0“gross profit differences for use of PCU and preplant‐applied AA compared with urea in the low‐lying position could range from $50 to $642 ha −1”
Claim · model-written summary
Targeted nitrogen fertilizer sources in claypan landscapes may increase corn grain yields and profitability.
- Taxon
- CornZea mays subsp. mayst0
- Outcome
- grain yields and profitabilitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“targeted use of different N fertilizer sources in claypan landscapes may increase grain yields and profitability”
t0“Corn”
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