Fertilizer Nitrogen Use Efficiency on Sweet Corn Affected ...
Determining the Most Effective Growth Stage in Corn Production for Spectral Prediction of Grain...
1
Determining the Most Effective Growth Stage in Corn Production for Spectral Prediction of Grain Yield and Nitrogen Response Department of Plant and Soil Sciences Department of Biosystems and Agricultural Engineering R.K. Teal, K.W. Freeman, W.R. Raun, J. Mosali, K.L. Martin , G.V. Johnson, J.B. Solie, and H. Zh Oklahoma State University With the escalation in environmental concern and cost of production, researchers have recently focused on investigating more efficient means of increasing grain yield while reducing fertilizer use. This study evaluated spectral reflectance, measuring the normalized difference vegetation index (NDVI) with a GreenSeeker® Hand Held optical reflectance sensor as a function of corn (Zea mays L.) hybrid, plant population, and fertilizer N rate. Initial investigation of these variables in 2002 and 2003 concluded that higher plant populations (>49,400 plants ha-1) caused early canopy closure, resulting in NDVI peaks at V10, where as NDVI did not peak at lower plant populations (35,568 plants ha- 1) until R1. In the spring of 2004 with the addition of a third site and the availability of a green NDVI sensor, the trials were reconfigured removing one hybrid and imposing two more plant populations and the utilization of both green and red NDVI. Green NDVI values peaked between V7 and V8 when compared to red NDVI (peaked at V11) and green NDVI was not affected by plant population in the vegetative stages, as was red NDVI. Plant population increased NDVI measurements and reduced coinciding coefficient of variation (CV) measurements significantly as population increased from 37,050 to 66,690 plants ha -1 , but no differences occurring between 66,690 and 81,510 plants ha -1 . Green NDVI, Red NDVI, and CV were all highly correlated at V7, V8, and V9 growth stages. Coefficient of Variation data from V8 showed a relationship with measured plant population at sufficient N levels. Grain yield correlated well with both green and red NDVI at V8 and V9 growth stages. Vegetative response index (RI NDVI ) peaked between V8 and V9 at responsive locations, however correlation with final RI (RI HARVEST) was limited. Regression analysis indicated that early-season grain yield prediction and vegetative RI measurement was hybrid and site sensitive and needs further refining to improve accuracy. Nevertheless, t his study revealed that N response could be determined at early growth stages using either Green or Red NDVI and that the potential exists to predict grain yield using either band. Abstract •Three experimental sites were established in the spring of 2004 •Eastern Oklahoma Research Station near Haskell, OK on Taloka silt loam soil (fine, mixed, thermic Mollic Albaqiustoll) •Lake Carl Blackwell Agronomy Research Farm near Stillwater, OK on Pulaski fine sandy loam soil (course-loamy, mixed, nonacid, thermic Typic Ustifluvent) •Greenlee Farm near Morris, OK on Taloka silt loam soil (fine, mixed, thermic Mollic Albaqiustoll) •Ammonium Nitrate (34-0-0) was broadcast at 0, 84, and 168 kg N ha -1 by hand and incorporated in the soil shortly before planting •Two Bacillus thuringiensis (bt) gene enhanced corn hybrids identified by their maturity date (99-day and 113-day) were planted at each site in 2004 •Four seeding rates were evaluated in 76 cm rows •37,050, 51,870, 66,690, and 81,510 plants ha -1 •Sensor readings were taken with a GreenSeeker Hand Held optical reflectance sensor (Ntech Industries, Ukiah, CA), measuring Red and Green, normalized difference vegetation index (NDVI) at different vegetative and reproductive growth stages •Corn grain was harvested by hand, removing 2 rows x 9.14 m from the center of each plot •Grain yield from each plot was determined and a sub-sample was taken for total N analysis •Red NDVI = [(NIRref/NIRinc)-(Redref/Redinc)] / [(NIRref/NIRinc)+(Redref/Redinc)] •Green NDVI=[(NIRref/NIRinc)-(Greenref/Greeninc)] / [(NIRref/NIRinc)+(Greenref/Greeninc)] •Response indices (RI) •Vegetative = calculated by dividing the highest N treated NDVI average by the check (0 N rate) average •Harvest = highest N treated grain yield average divided by the check (0 N rate) average Materials and Methods Conclusions Plant population can influence NDVI and grain yield prediction CV can be used to predict plant population (improve yield prediction) Green and Red NDVI from V8 and V9 growth stages was highly correlated with grain yield Green and Red NDVI worked equally well for predicting grain yield from V7 to V9 Different yield prediction curves will be necessary for Green and Red NDVI Vegetative response index (RI NDVI ) to N peaked between V8 and V9 at responsive locations Need for added N can be determined early in season while the crop is small enough for side-dress N applications Regression analysis indicated that early-season grain yield prediction and vegetative RI measurement was hybrid and site Coefficient of determination (R 2 ) Greenlee Farm V7 V8 V9 Green NDVI 99-day 0.368 0.258 0.399 113-day 0.344 0.319 0.433 Red NDVI 99-day 0.179 0.254 0.500 113-day 0.412 0.221 0.467 Haskell V7 V8 V9 Green NDVI 99-day NA 0.751 0.679 113-day NA 0.644 0.673 Red NDVI 99-day NA 0.745 0.671 113-day NA 0.598 0.558 Lake Carl Blackwell V7 V8 V9 Green NDVI 99-day 0.429 0.502 0.548 113-day 0.163 0.322 0.250 Red NDVI 99-day 0.545 0.549 0.529 113-day 0.143 0.281 0.273 Exponential regression, NDVI and grain yield Linear regression, RI NDVI and RI HARVEST 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 GNDVI 37,050 51,870 66,690 81,510 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 RNDVI 37,050 51,870 66,690 81,510 0 10 20 30 40 50 60 V5 V6 V8 V9 V 11 R1 R2-R 3 R4 R5 Red CV 37,050 51,870 66,690 81,510 0 10 20 30 40 50 60 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 G reen C V 37,050 51,870 66,690 81,510 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 GNDVI 0 N 84 N 168 N 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 V5 V6 V8 V9 V 11 R1 R2-R 3 R4 R5 RNDVI 0 N 84 N 168 N 0 5 10 15 20 25 30 35 40 45 50 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 G reen C V 0 N 84 N 168 N 0 5 10 15 20 25 30 35 40 45 50 V5 V6 V8 V9 V 11 R1 R2-R3 R4 R5 R ed C V 0 N 84 N 168 N Coefficient of determination (R 2 ) Greenlee Farm V7 V8 V9 Green RI NDVI 99-day 0.039 0.010 0.183 113-day 0.434 0.255 0.614 Red RI NDVI 99-day 0.069 0.003 0.086 113-day 0.325 0.541 0.556 Haskell V7 V8 V9 Green RI NDVI 99-day NA 0.235 0.056 113-day NA 0.092 0.251 Red RI NDVI 99-day NA 0.161 0.239 113-day NA 0.396 0.529 Lake Carl Blackwell V7 V8 V9 Green RI NDVI 99-day 0.764 0.819 0.757 113-day 0.381 0.823 0.625 Red RI NDVI 99-day 0.593 0.603 0.686 113-day 0.671 0.681 0.817 y = 3060.5e 1.7866x R 2 = 0.3567 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 0 0.2 0.4 0.6 0.8 GNDVI G rain yield (kg/ha) y = 1033.8e 3.5346x R 2 = 0.6749 0 2000 4000 6000 8000 10000 12000 14000 0 0.2 0.4 0.6 0.8 GNDVI G rain yield (kg/ha) y = 1349.7e 2.6383x R 2 = 0.659 0 2000 4000 6000 8000 10000 12000 14000 0 0.2 0.4 0.6 0.8 1 RNDVI G rain yield (kg/ha) Relationship between grain yield and NDVI at V8, 113-day hybrid over three locations Relationship between grain yield and NDVI at V8, 99-day hybrid over three locations y = 27.786e -1E -05x R 2 = 0.5138 0 10 20 30 40 50 60 70 0 20,000 40,000 60,000 80,000 100,000 P lantpop.(plants/ha) G reen C V y = 54.352e -2E-05x R 2 = 0.5748 0 10 20 30 40 50 60 70 0 20,000 40,000 60,000 80,000 100,000 P lantpop.(plants/ha) R ed C V Relationship between plant population and CV from Green and Red NDVI at V8 in the 99-day hybrid with sufficient N over three locations Influence of N rate on CV from Green and Red NDVI at V8 in the 99-day hybrid with high plant population, Haskell, OK Influence of plant population on CV from Green and Red NDVI at V8 in the 99- day hybrid with sufficient nitrogen, Haskell, OK Influence of plant population on Green and Red NDVI at V8 in the 99-day hybrid with sufficient N, Haskell, OK Influence of N rate on Green and Red NDVI at V8 in the 99-day hybrid with high plant population, Haskell, OK y = 3067.3e 1.5258x R 2 = 0.3734 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 0 0.2 0.4 0.6 0.8 1 RNDVI G rain yield (kg/ha)
-
Upload
roger-mckenzie -
Category
Documents
-
view
216 -
download
3
Transcript of Determining the Most Effective Growth Stage in Corn Production for Spectral Prediction of Grain...
Determining the Most Effective Growth Stage in Corn Production for Spectral Prediction of Grain Yield and Nitrogen Response Department of Plant and Soil Sciences
Department of Biosystems and Agricultural Engineering R.K. Teal, K.W. Freeman, W.R. Raun, J. Mosali, K.L. Martin , G.V. Johnson, J.B. Solie, and H. Zhang
Oklahoma State UniversityOklahoma State University
With the escalation in environmental concern and cost of production, researchers have recently focused on investigating more efficient means of increasing grain yield while reducing fertilizer use. This study evaluated spectral reflectance, measuring the normalized difference vegetation index (NDVI) with a GreenSeeker® Hand Held optical reflectance sensor as a function of corn (Zea mays L.) hybrid, plant population, and fertilizer N rate. Initial investigation of these variables in 2002 and 2003 concluded that higher plant populations (>49,400 plants ha-1) caused early canopy closure, resulting in NDVI peaks at V10, where as NDVI did not peak at lower plant populations (35,568 plants ha-1) until R1. In the spring of 2004 with the addition of a third site and the availability of a green NDVI sensor, the trials were reconfigured removing one hybrid and imposing two more plant populations and the utilization of both green and red NDVI. Green NDVI values peaked between V7 and V8 when compared to red NDVI (peaked at V11) and green NDVI was not affected by plant population in the vegetative stages, as was red NDVI. Plant population increased NDVI measurements and reduced coinciding coefficient of variation (CV) measurements significantly as population increased from 37,050 to 66,690 plants ha-1, but no differences occurring between 66,690 and 81,510 plants ha-1. Green NDVI, Red NDVI, and CV were all highly correlated at V7, V8, and V9 growth stages. Coefficient of Variation data from V8 showed a relationship with measured plant population at sufficient N levels. Grain yield correlated well with both green and red NDVI at V8 and V9 growth stages. Vegetative response index (RINDVI) peaked between V8 and V9 at responsive locations, however correlation with final RI (RIHARVEST) was limited. Regression analysis indicated that early-season grain yield prediction and vegetative RI measurement was hybrid and site sensitive and needs further refining to improve accuracy. Nevertheless, this study revealed that N response could be determined at early growth stages using either Green or Red NDVI and that the potential exists to predict grain yield using either band.
Abstract
•Three experimental sites were established in the spring of 2004•Eastern Oklahoma Research Station near Haskell, OK on Taloka silt loam soil (fine, mixed, thermic Mollic Albaqiustoll)•Lake Carl Blackwell Agronomy Research Farm near Stillwater, OK on Pulaski fine sandy loam soil (course-loamy, mixed, nonacid, thermic Typic Ustifluvent)•Greenlee Farm near Morris, OK on Taloka silt loam soil (fine, mixed, thermic Mollic Albaqiustoll)
•Ammonium Nitrate (34-0-0) was broadcast at 0, 84, and 168 kg N ha-1 by hand and incorporated in the soil shortly before planting•Two Bacillus thuringiensis (bt) gene enhanced corn hybrids identified by their maturity date (99-day and 113-day) were planted at each site in 2004 •Four seeding rates were evaluated in 76 cm rows
•37,050, 51,870, 66,690, and 81,510 plants ha -1
•Sensor readings were taken with a GreenSeeker Hand Held optical reflectance sensor (Ntech Industries, Ukiah, CA), measuring Red and Green, normalized difference vegetation index (NDVI) at different vegetative and reproductive growth stages •Corn grain was harvested by hand, removing 2 rows x 9.14 m from the center of each plot•Grain yield from each plot was determined and a sub-sample was taken for total N analysis •Red NDVI = [(NIRref/NIRinc)-(Redref/Redinc)] / [(NIRref/NIRinc)+(Redref/Redinc)] •Green NDVI=[(NIRref/NIRinc)-(Greenref/Greeninc)] / [(NIRref/NIRinc)+(Greenref/Greeninc)]•Response indices (RI)
•Vegetative = calculated by dividing the highest N treated NDVI average by the check (0 N rate) average•Harvest = highest N treated grain yield average divided by the check (0 N rate) average
Materials and Methods
Conclusions
Plant population can influence NDVI and grain yield prediction CV can be used to predict plant population (improve yield prediction)Green and Red NDVI from V8 and V9 growth stages was highly correlated with grain yieldGreen and Red NDVI worked equally well for predicting grain yield from V7 to V9Different yield prediction curves will be necessary for Green and Red NDVI Vegetative response index (RINDVI) to N peaked between V8 and V9 at responsive locationsNeed for added N can be determined early in season while the crop is small enough for side-dress N applicationsRegression analysis indicated that early-season grain yield prediction and vegetative RI measurement was hybrid and site sensitive and needs further refining to improve accuracy
Coefficient of determination (R2)
Greenlee Farm V7 V8 V9
Green NDVI
99-day 0.368 0.258 0.399
113-day 0.344 0.319 0.433
Red NDVI
99-day 0.179 0.254 0.500
113-day 0.412 0.221 0.467
Haskell V7 V8 V9
Green NDVI
99-day NA 0.751 0.679
113-day NA 0.644 0.673
Red NDVI
99-day NA 0.745 0.671
113-day NA 0.598 0.558
Lake Carl Blackwell V7 V8 V9
Green NDVI
99-day 0.429 0.502 0.548
113-day 0.163 0.322 0.250
Red NDVI
99-day 0.545 0.549 0.529
113-day 0.143 0.281 0.273
Exponential regression, NDVI and grain yield Linear regression, RINDVI and RIHARVEST
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
GN
DV
I
37,050 51,870 66,690 81,510
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
RN
DV
I
37,050 51,870 66,690 81,510
0
10
20
30
40
50
60
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
Red
CV
37,050 51,870 66,690 81,510
0
10
20
30
40
50
60
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
Gre
en C
V
37,050 51,870 66,690 81,510
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
GN
DV
I
0 N 84 N 168 N
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
RN
DV
I
0 N 84 N 168 N
0
5
10
15
20
25
30
35
40
45
50
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
Gre
en C
V
0 N 84 N 168 N
0
5
10
15
20
25
30
35
40
45
50
V5 V6 V8 V9 V11 R1 R2-R3 R4 R5
Red
CV
0 N 84 N 168 N
Coefficient of determination (R2)
Greenlee Farm V7 V8 V9
Green RINDVI
99-day 0.039 0.010 0.183
113-day 0.434 0.255 0.614
Red
RINDVI
99-day 0.069 0.003 0.086
113-day 0.325 0.541 0.556
Haskell V7 V8 V9
Green RINDVI
99-day NA 0.235 0.056
113-day NA 0.092 0.251
Red
RINDVI
99-day NA 0.161 0.239
113-day NA 0.396 0.529
Lake Carl Blackwell V7 V8 V9
Green RINDVI
99-day 0.764 0.819 0.757
113-day 0.381 0.823 0.625
Red
RINDVI
99-day 0.593 0.603 0.686
113-day 0.671 0.681 0.817
y = 3060.5e1.7866x
R2 = 0.3567
02000400060008000
100001200014000160001800020000
0 0.2 0.4 0.6 0.8
GNDVI
Gra
in y
ield
(kg
/ha)
y = 1033.8e3.5346x
R2 = 0.6749
0
2000
4000
6000
8000
10000
12000
14000
0 0.2 0.4 0.6 0.8
GNDVI
Gra
in y
ield
(kg
/ha)
y = 1349.7e2.6383x
R2 = 0.659
0
2000
4000
6000
8000
10000
12000
14000
0 0.2 0.4 0.6 0.8 1
RNDVI
Gra
in y
ield
(kg
/ha)
Relationship between grain yield and NDVI at V8, 113-day hybrid over three locations
Relationship between grain yield and NDVI at V8, 99-day hybrid over three locations
y = 27.786e-1E-05x
R2 = 0.5138
0
10
20
30
40
50
60
70
0 20,000 40,000 60,000 80,000 100,000
Plant pop. (plants/ha)
Gre
en C
V
y = 54.352e-2E-05x
R2 = 0.5748
0
10
20
30
40
50
60
70
0 20,000 40,000 60,000 80,000 100,000
Plant pop. (plants/ha)
Red
CV
Relationship between plant population and CV from Green and Red NDVI at V8 in the 99-day hybrid with sufficient N over three locations
Influence of N rate on CV from Green and Red NDVI at V8 in the 99-day hybrid with high plant population, Haskell, OK
Influence of plant population on CV from Green and Red NDVI at V8 in the 99-day hybrid with sufficient nitrogen, Haskell, OK
Influence of plant population on Green and Red NDVI at V8 in the 99-day hybrid with sufficient N, Haskell, OK
Influence of N rate on Green and Red NDVI at V8 in the 99-day hybrid with high plant population, Haskell, OK
y = 3067.3e1.5258x
R2 = 0.3734
02000400060008000
100001200014000160001800020000
0 0.2 0.4 0.6 0.8 1
RNDVI
Gra
in y
ield
(kg
/ha)
