Abstract
Precise nitrogen (N) fertilizer management in corn requires accurate and timely analysis of plant tissue N status throughout the growing season. Chlorophyll meter readings (CMR) were compared to laboratory analyzed tissue N (TN) during two growing seasons in corn preplant fertilized with variable rates of N provided by cattle manure and urea. Although a positive linear relationship between CMR and TN was observed on most July and August sampling dates of the seasons, the regression coefficients varied between sampling dates. When days after planting and CMR for both years were included in a multiple regression equation, 84% of TN variability was explained. Both CMR and TN were highly correlated with final crop yield. A critical CMR value of 52 at anthesis was suggested to prevent corn yield reductions. Based on the results from this study, it is evident that the chlorophyll meter may prove to be a valuable tool in fertigation management.
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Claims 7
Claim · model-written summary
Chlorophyll meter readings and tissue nitrogen had a positive linear relationship on most July and August dates.
- Taxon
- corn
Zea mays subsp. mayst0 - Outcome
- tissue N (TN)e1
- Direction
- positivee0
- Qualifier
- most July and August sampling datese0
- Comparator
- Chlorophyll meter readings (CMR)e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“a positive linear relationship between CMR and TN was observed on most July and August sampling dates of the seasons”
e1“Chlorophyll meter readings (CMR) were compared to laboratory analyzed tissue N (TN)”
t0“corn”
Claim · model-written summary
Regression coefficients varied between sampling dates.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- regression coefficientse0
- Direction
- variede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the regression coefficients varied between sampling dates”
t0“corn”
Claim · model-written summary
Days after planting and chlorophyll meter readings explained 84% of tissue nitrogen variability.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- TN variabilitye0
- Value
- 84%e0
- Qualifier
- days after planting and CMR for both yearse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“When days after planting and CMR for both years were included in a multiple regression equation, 84% of TN variability was explained”
t0“corn”
Claim · model-written summary
Chlorophyll meter readings were highly correlated with final crop yield.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- final crop yielde0
- Comparator
- Chlorophyll meter readings (CMR)e1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both CMR and TN were highly correlated with final crop yield”
e1“Chlorophyll meter readings (CMR)”
t0“corn”
Claim · model-written summary
Tissue nitrogen was highly correlated with final crop yield.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- final crop yielde0
- Comparator
- tissue N (TN)e1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both CMR and TN were highly correlated with final crop yield”
e1“laboratory analyzed tissue N (TN)”
t0“corn”
Claim · model-written summary
The authors suggest a chlorophyll meter reading of 52 at anthesis to prevent yield reductions.
- Taxon
- cornZea mays subsp. mayse0
- Organ / stage
- anthesise0
- Outcome
- prevent corn yield reductionse0
- Value
- 52e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A critical CMR value of 52 at anthesis was suggested to prevent corn yield reductions”
Claim · model-written summary
The authors consider the chlorophyll meter valuable for fertigation management.
- Taxon
- cornZea mays subsp. mayst0
- Outcome
- valuable tool in fertigation managemente0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the chlorophyll meter may prove to be a valuable tool in fertigation management”
t0“corn”