Abstract
Agronomic research on the effects of nitrogen fertilizer and weed control in corn has focused primarily on maintaining or increasing yield. Few studies have examined the effect of nitrogen (N) fertilizer rate or weed competition (or both) on whole plant growth and development. The objectives of this research were to determine how N influences the growth and development of corn and to explore how green foxtail density affects this relationship. Field experiments were conducted on a sandy low organic matter soil from 1999 to 2001. The experiment was designed as a factorial with N rate ranging from 0 to 200 kg N ha −1 and targeted green foxtail density ranging from 0 to 300 plants m −2 . Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight. However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level. Despite having significant main effects, there was no interaction between N rate and green foxtail density. Results indicate that in corn grown on a coarse-textured soil with low organic matter, the additional stress brought about by the presence of green foxtail exacerbated the effect of low N rates on corn growth and development. More intensive weed management may be required in corn if N fertilizer rates are reduced.
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Claims 13
Claim · model-written summary
Higher nitrogen fertilizer increased corn leaf and grain N content under weed-free conditions.
- Taxon
- corn
Zea mays subsp. mayse0 - Treatment
- a higher rate of N fertilizere0
- Outcome
- corn leaf and grain N contente0
- Direction
- increasede0
- Comparator
- weed-free conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight.”
Claim · model-written summary
Higher nitrogen fertilizer increased leaf area index (LAI) under weed-free conditions.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- a higher rate of N fertilizere0
- Outcome
- leaf area index (LAI)e0
- Direction
- increasede0
- Comparator
- weed-free conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight.”
Claim · model-written summary
Higher nitrogen fertilizer increased plant height under weed-free conditions.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- a higher rate of N fertilizere0
- Outcome
- plant heighte0
- Direction
- increasede0
- Comparator
- weed-free conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight.”
Claim · model-written summary
Higher nitrogen fertilizer increased aboveground dry matter (DM) production under weed-free conditions.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- a higher rate of N fertilizere0
- Outcome
- aboveground dry matter (DM) productione0
- Direction
- increasede0
- Comparator
- weed-free conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight.”
Claim · model-written summary
Higher nitrogen fertilizer increased kernel weight under weed-free conditions.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- a higher rate of N fertilizere0
- Outcome
- kernel weighte0
- Direction
- increasede0
- Comparator
- weed-free conditionse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight.”
Claim · model-written summary
Green foxtail reduced corn leaf N content at each nitrogen level.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- presence of green foxtaile0
- Interactor
- green foxtaile0weed
- Outcome
- corn leaf N contente0
- Direction
- reducede0
- Comparator
- each N levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level.”
Claim · model-written summary
Green foxtail reduced LAI at each nitrogen level.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- presence of green foxtaile0
- Interactor
- green foxtaile0weed
- Outcome
- LAIe0
- Direction
- reducede0
- Comparator
- each N levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level.”
Claim · model-written summary
Green foxtail reduced growth rate at each nitrogen level.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- presence of green foxtaile0
- Interactor
- green foxtaile0weed
- Outcome
- growth ratee0
- Direction
- reducede0
- Comparator
- each N levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level.”
Claim · model-written summary
Green foxtail reduced plant height at each nitrogen level.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- presence of green foxtaile0
- Interactor
- green foxtaile0weed
- Outcome
- plant heighte0
- Direction
- reducede0
- Comparator
- each N levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level.”
Claim · model-written summary
Green foxtail reduced aboveground DM at each nitrogen level.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- presence of green foxtaile0
- Interactor
- green foxtaile0weed
- Outcome
- aboveground DMe0
- Direction
- reducede0
- Comparator
- each N levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level.”
Claim · model-written summary
Nitrogen rate and green foxtail density had significant main effects but no interaction.
- Taxon
- cornZea mays subsp. mayst0
- Interactor
- green foxtaile0weed
- Outcome
- no interaction between N rate and green foxtail densitye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Despite having significant main effects, there was no interaction between N rate and green foxtail density.”
t0“corn growth and development”
Claim · model-written summary
Green foxtail exacerbated the effect of low nitrogen on corn growth in coarse-textured, low-organic-matter soil.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- low N ratese0
- Interactor
- green foxtaile0weed
- Outcome
- corn growth and developmente0
- Qualifier
- coarse-textured soil with low organic mattere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Results indicate that in corn grown on a coarse-textured soil with low organic matter, the additional stress brought about by the presence of green foxtail exacerbated the effect of low N rates on corn growth and development.”
Claim · model-written summary
More intensive weed management may be required when nitrogen rates are reduced.
- Taxon
- cornZea mays subsp. mayse0
- Outcome
- More intensive weed managemente0
- Qualifier
- if N fertilizer rates are reducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“More intensive weed management may be required in corn if N fertilizer rates are reduced.”
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