Abstract
Problem statement: Insufficient rainfall under low yield environment may affect nitrogen management, plant growth indices and grain yields of corn (Zea mays L.). Approach: The objective of this study was to determine the effects of two N application timings (all at planting and as split application with N applied at planting and V6 stage) and five N fertilizer rates (0, 45, 90, 135 and 180 kg N ha -1 ) on strip-tilled, dryland corn growth and yields under low-yield environmental conditions near Blackville SC, from 2007-2009. Plant growth measurements included plant height, ear height, relative chlorophyll content (SPAD), Leaf Area Index (LAI) and normalized difference vegetation index (NDVI). Results: Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates. Due to most likely insufficient precipitation, the N application timing did not affect corn growth or yield. Despite relatively low grain yields, corn yield was increased by 1.6 Mg ha -1 with increasing N application rate of 100 kg ha -1 . Grain yield was positively correlated with plant leaf area index (LAI) at R1 (r = 0.27, p0.05) and Normalized Difference Vegetation Index (NDVI) at V8 and R1 (r = 0.33 and 0.29, p0.01, respectively) and plant height at V8 stage (r = 0.42, p0.001). With N applied at planting, there was a 0.55 and 0.49 Mg ha -1 yield increase with 0.1 increases in plant NDVI at V8 and R1, respectively. Conclusion: Under strip tillage and low yield environment conditions, plant growth and yields may not be affected by timing of N application mainly due to insufficient rainfall. Plant NDVI (for treatments with all N applied at planting) at V8 and R1 can help to estimate potential of corn grain yield, which may be reduced due to low nitrogen use efficiency.
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Claims 14
Claim · model-written summary
Leaf area index at V8 increased with nitrogen application rate.
- Taxon
- Corn
Zea mays subsp. mayst0 - Treatment
- N application ratese0
- Outcome
- Plant LAI at V8e0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates.”
t0“Corn”
Claim · model-written summary
NDVI at V8 and R1 increased with nitrogen application rate.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- N application ratese0
- Outcome
- NDVI at V8 and R1e0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates.”
t0“Corn”
Claim · model-written summary
SPAD at R1 increased with nitrogen application rate.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- N application ratese0
- Outcome
- SPAD at R1e0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates.”
t0“Corn”
Claim · model-written summary
Plant height at V8 increased with nitrogen application rate.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- N application ratese0
- Outcome
- plant height at V8e0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates.”
t0“Corn”
Claim · model-written summary
Grain yield increased with nitrogen application rate.
- Taxon
- CornZea mays subsp. mayst0
- Treatment
- N application ratese0
- Outcome
- grain yielde0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates.”
t0“Corn”
Claim · model-written summary
Nitrogen timing did not affect corn growth or yield, possibly because of insufficient precipitation.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- N application timinge0
- Outcome
- corn growth or yielde0
- Direction
- did not affecte0
- Qualifier
- most likely insufficient precipitatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Due to most likely insufficient precipitation, the N application timing did not affect corn growth or yield.”
Claim · model-written summary
Increasing nitrogen rate by 100 kg ha -1 increased corn yield by 1.6 Mg ha -1.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- N application rate of 100 kg ha -1e0
- Outcome
- corn yielde0
- Direction
- increasede0
- Value
- 1.6 Mg ha -1e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“corn yield was increased by 1.6 Mg ha -1 with increasing N application rate of 100 kg ha -1”
Claim · model-written summary
Grain yield was positively correlated with leaf area index at R1.
Verbatim
e0“Grain yield was positively correlated with plant leaf area index (LAI) at R1 (r = 0.27, p0.05)”
Claim · model-written summary
Grain yield was positively correlated with NDVI at V8.
Verbatim
e0“Grain yield was positively correlated with plant leaf area index (LAI) at R1 (r = 0.27, p0.05) and Normalized Difference Vegetation Index (NDVI) at V8 and R1 (r = 0.33 and 0.29, p0.01, respectively)”
Claim · model-written summary
Grain yield was positively correlated with NDVI at R1.
Verbatim
e0“Grain yield was positively correlated with plant leaf area index (LAI) at R1 (r = 0.27, p0.05) and Normalized Difference Vegetation Index (NDVI) at V8 and R1 (r = 0.33 and 0.29, p0.01, respectively)”
Claim · model-written summary
Grain yield was positively correlated with plant height at V8.
- Taxon
- CornZea mays subsp. mayst0
- Organ / stage
- V8 stagee0
- Outcome
- plant heighte0
- Direction
- positively correlatede1
- Value
- r = 0.42e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“and plant height at V8 stage (r = 0.42, p0.001)”
e1“Grain yield was positively correlated with plant leaf area index”
t0“Corn”
Claim · model-written summary
For planting-time nitrogen application, a 0.1 NDVI increase at V8 corresponded to a 0.55 Mg ha -1 yield increase.
Verbatim
e0“With N applied at planting, there was a 0.55 and 0.49 Mg ha -1 yield increase with 0.1 increases in plant NDVI at V8 and R1, respectively.”
Claim · model-written summary
For planting-time nitrogen application, a 0.1 NDVI increase at R1 corresponded to a 0.49 Mg ha -1 yield increase.
Verbatim
e0“With N applied at planting, there was a 0.55 and 0.49 Mg ha -1 yield increase with 0.1 increases in plant NDVI at V8 and R1, respectively.”
Claim · model-written summary
NDVI at V8 and R1 may estimate potential grain yield under planting-time nitrogen application.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- all N applied at plantinge0
- Outcome
- corn grain yielde0
- Qualifier
- at V8 and R1e0
Not reportedComparatorValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Plant NDVI (for treatments with all N applied at planting) at V8 and R1 can help to estimate potential of corn grain yield”
The same questions in other papers
nitrogen · yield · Zea mays (maize)Positive and negative results
278 papers in the same direction as this paper · 1,906 in the opposite direction
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See all 2,185 papers →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.