Transcript Application of Crop Growth Models in Precision Agriculture

NUE Workshop: Improving NUE using Crop Sensing, Waseca, MN
Comparing Different Remote Sensing Approaches for
Early Season Nitrogen Deficiency Detection in Corn
Yuxin Miao1, David J. Mulla1, Gyles W. Randall2,
Jeff A. Vetsch2, and Roxana Vintila3
1. Precision Agriculture Center, University of Minnesota.
2. Southern Research and Outreach Center, University of Minnesota.
3. Research Institute of Soil Science and Agrochemistry (ICPA), Romania.
Different Sensing Approaches for Precision N Management
Chlorophyll Meter:
SPAD 502
GreenSeeker:
CropScan Multispectral Radiometer:
Different Sensing Approaches for Precision N Management
Aerial or Satellite -based Remote Sensing:
High spatial resolution remote sensing images are potentially cheaper,
more efficient and more spatially detailed than chlorophyll meter or
other ground-based hand-held sensors.
Hyperspectral Remote Sensing
(Image from http://www.eoc.csiro.au/hswww/Overview.htm)
Objectives
Identify hyperspectral bands (wavelengths), band
ratios and vegetation indices that are sensitive to early
season corn plant N status;
To compare the effectiveness of different sensing
approaches to monitor early season corn plant N status
and detect N deficiency:
 SPAD Meter;
 GreenSeeker;
 CropScan multispectral radiometer;
 Aerial hyperspectral remote sensing; and,
 Aerial multispectral remote sensing (simulated).
Materials and Methods – Study Sites
Field 1: Corn-Soybean Rotation
Field 2: Corn-Corn Rotation
Materials and Methods – N Treatments
3 x 15.2 m
Field 1, Corn-Soybean Rotation
Materials and Methods – N Treatments
Field 2, Corn-Corn Rotation
Materials and Methods – Data Collection
 N Concentration:
 V9: Whole plant sampling, 10 plants: N concentration, biomass;
 R1: Ear leaf, 10 leaves;
 Harvest: grain and stover.
 SPAD Meter:
 F1: V9, V11, R1, and R3;
 F2: V7, V9-10, V12, R1, R3
 Collected 30 readings from each plot.
 GreenSeeker:
 F1: V9 and V11;
 F2: V8, V9-10, V11-V12 and V12.
 CropScan Multispectral Radiometer:
 V6 and V9;
 About 50 cm above the canopy, three samples each plot.
Materials and Methods – Data Collection
 Aerial Hyperspectral Remote Sensing:
AISA-Eagle (AE) Hyperspectral Imager
61 bands from 392 – 982 nm, at 8.76 – 9.63nm;
At 0.75 m spatial resolution;
V9, R1, R2 and R4;
Pixels of the central two rows in each plot were averaged;
 Simulated Multispectral Remote Sensing:
Landsat ETM+ sensor’s four broad bands:
 Blue: 450-515nm;
 Green: 525-605nm;
 Red: 630-690 nm;
 NIR: 775-900nm.
Materials and Methods – Band Combinations
 Simple Ratio (SR)
Ratio
Definition
Reference
Green Index
Zarco-Tejada & Miller (ZTM)
PSSRa
PSSRb
PSSRc
SPRI
SR1
SR2
SR3
SR4
SR5
SR6
SR7
R554/R677
R750/R710
R800/R680
R800/R635
R800/R470
R430/R680
NIR/Red = R801/R670
NIR/Green=R800/R550
R700/R670
R740/R720
R675/(R700 x R650)
R672/(R550 x R708)
R860/(R550 x R708)
Smith et al., 1995
Zarco-Tejada et al., 2001
Blackburn, 1998
Blackburn, 1998
Blackburn, 1998
Penuelas et al., 1994
Daughtry et al., 2000
Buschman and Nagel, 1993
McMurtrey et al., 1994
Vogelman et al., 1993
Chappelle et al., 1992
Datt, 1998
Datt, 1998
Materials and Methods – Band Combinations
 Difference Index (DI) and Normalized Difference Index (NDI)
Index
Definition
Reference
DI1
DVI
NDVI
Green NDVI
PSNDb
PSNDc
NPCI
NPQI
SIPI
mND705
mSR705
NDI1
NDI2
NDI3
R800-R550
R800-R680
(R800-R680)/(R800+R680)
(R801-R550)/(R800+R550)
(R800-R635)/(R800+R635)
(R800-R470)/(R800+R470)
(R680-R430)/(R680+R430)
(R415-R435)/(R415+R435)
(R800-R445)/(R800-R680)
(R750-R705)/(R750+R705-2 x R445)
(R750-R445)/(R705-R445)
(R780-R710)/(R780-R680)
(R850-R710)/(R850-R680)
(R734-R747)/(R715+R726)
Buschman and Nagel, 1993
Jordan, 1969
Lichtenthaler et al., 1996
Daughtry et al., 2000
Blackburn, 1998
Blackburn, 1998
Penuelas et al., 1994
Barnes et al., 1992
Penuelas et al., 1995
Sims and Gamon, 2002
Sims and Gamon, 2002
Datt, 1999
Datt, 1999
Vogelman et al., 1993
Materials and Methods – Band Combinations
 Integrated Index (II)
Index
Definition
Reference
MCARI
TCARI
OSAVI
TCAVI/OSAVI
TVI
MCARI/OSAVI
RDVI
MSR
MSAVI
MTVI
[(R700-R670)-0.2x(R700-R550)](R700/R670)
3x[(R700-R670)-0.2x(R700-R550)(R700/R670)]
(1+0.16)(R800-R670)/(R800+R670+0.16)
Daughtry et al., 2000
Haboudane et al., 2002
Rondeaux et al., 1996
Haboudane et al., 2002
Broge and Leblanc, 2000
Zarco-Tejada et al., 2004
Rougean and Breon, 1995
Chen, 1996
Qi et al., 1994
Haboudane et al., 2004
0.5x[120x(R750-R550)-200x(R670-R550)]
(R800-R670)/SQRT(R800+R670)
(R800/R670-1)/SQRT(R800/R670+1)
0.5x[2xR800+1-SQRT((2xR800+1)2-8x(R800-R670))]
1.2x[1.2x(R800-R550)-2.5x(R670-R550)]
 Broad Band Combinations
 NIR/Green;
 NIR/Red;
 Blue NDVI;
 Green NDVI;
 Red NDVI.
Materials and Methods – Analysis
 Correlation analysis;
 Multiple linear regression;
 Nitrogen Sufficiency Index (NSI)
Yield, Plant N, SPAD, or index
NSI =
x 100%
Reference value
F1: the average of the highest two preplant N rates: 168 and 202 kg ha-1.
F2: 224 kg ha-1.
NSI of Plant N Concentration as standard
Results and Discussion:
Plant N Variability
36.1
34
31.9
28.2
24.9
CV = 9.33%
CV = 14.06%
202 kg ha-1
18.7
224 kg ha-1
Impact of N Rate on Reflectance
70
60
50
40
30
20
10
0
CropScan MSR
0 kg/ha
45 kg/ha
179 kg/ha
224 kg/ha
400
800 1200 1600
Wavelength (nm)
2000
45
40
Reflectance (%)
Reflectance(%)
Results and Discussion:
0 kg/ha
35
30
25
45 kg/ha
179 kg/ha
224 kg/ha
20
15
10
5
0
Hyperspectral RS
400
500
600 700 800
Wavelength (nm)
900
1000
Results and Discussion: Sensitive Wavelengths
Correlation between plant N concentration and CropScan
reflectance at V9
Correlation Coefficient
760-1000nm
0.60
F1
F2
0.40
0.20
0.00
-0.20
-0.40
-0.60
450
650
850
1050
1250
1450
Wavelength (nm)
560-710nm
1650
1850
Results and Discussion: Sensitive Wavelengths
Correlation Coefficient
Correlation between plant N concentration and
hyperspectral reflectance at V9
742-982nm
0.60
0.40
F1
F2
0.20
0.00
-0.20
-0.40
-0.60
-0.80
350
450
550
650
750
850
Wavelength (nm)
554 and 563nm
695nm
950
Results and Discussion: Sensitive Indices
Correlation with Plant N Concentrations at V9
Field 1
Field 2
0.51
0.50
0.39
0.72
0.71
0.71
NDI1
0.47
0.78
NDI2
0.41
0.79
SPAD Meter:
0.58
0.85
GreenSeeker NDVI:
0.26
0.49
0.31
0.68
CropScan:
Hyperspectral:
Simulated Landsat ETM+:
GNDVI:
NIR/Green: R800/R550
NDI2
GNDVI:
Results and Discussion: Multiple Regression
Correlation Coefficient
Field 1
SPAD Meter:
Field 2
0.58
0.85
6 (F1)/5(F2) bands
0.77
0.79
5 (F1)/4(F2) Indices
0.67
0.79
Hyperspectral:
4 bands
4 (F1)/3(F2)indices
0.73
0.66
0.89
0.88
Simulated Landsat ETM+:
3 bands
2 indices
0.56
0.57
0.89
0.88
CropScan:
Results and Discussion: N Sufficiency Index
105
100
NSI (%)
NSI (%)
95
90
85
N Content (V9)
80
Yield
75
70
0
50
100
150
Nitrogen Rate (kg ha-1)
200
250
100
95
90
85
80
75
70
65
60
55
N Content(V9)
Yield
0
50
100
150
Nitrogen Rate (kg ha-1)
200
250
Results and Discussion: N Deficiency Detection
Treatment Level, Field 1, Corn-Soybean Rotation
ID Yield Plant N SPAD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CropScan Hyper Landsat
GS
TVI NIR/G
G
Results and Discussion: N Deficiency Detection
Treatment Level, Field 2
CropScan Hyper Landsat
ID Yield Plant N SPAD GS
DI1 NIR
SR7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Results and Discussion: N Deficiency Detection
Plot Level, Field 1, Corn-Soybean Rotation
Deficient Plots Sufficient Plots DS SD Overall Accuracy (%)
Plant N Content
34 (44)
26 (16)
0
0
100
SPAD Meter
3
26
0
0
48 (35)
GreenSeeker
15
17
19
9
53 (47)
CropScan: MCARI
22
14
12
12
60 (60)
Hyperspectral: MCARI
25
11
9
15
60 (55)
Landsat ETM+: Green
17
15
17
11
53 (62)
Results and Discussion: N Deficiency Detection
Plot Level, Field 2, Corn-Corn Rotation
Deficient Plots Sufficient Plots DS SD Total Accuracy (%)
Plant N Content
29 (46)
27 (10)
0
0
100
SPAD Meter
21
25
8
2
82 (71)
GreenSeeker
10
26
19
1
64 (43)
CropScan: TCARI/OSAVI
18
22
11
5
71 (59)
Hyperspectral: SR7
21
22
8
5
77 (61)
Landsat ETM+: NIR/Green 17
20
12
7
66 (57)
Results and Discussion: Promising Indices
 Normalized Difference Index 2 (NDI2)
NDI2 =
R850-R710
R850-R680
Reflectance (%)
45
40
0 kg/ha
35
30
25
45 kg/ha
179 kg/ha
224 kg/ha
20
15
10
5
0
400
500
600 700 800
Wavelength (nm)
900
1000
Results and Discussion: Promising Indices
 Simple Ratio 7
R860
SR7 =
R550 x R708
Reflectance (%)
45
40
0 kg/ha
35
30
25
45 kg/ha
179 kg/ha
224 kg/ha
20
15
10
5
0
400
500
600 700 800
Wavelength (nm)
900
1000
Conclusions
The sensors performed better in corn-corn rotation field
than in corn-soybean rotation field at V9;
The NIR region was most sensitive to N deficiency at V9;
Reflectance at around 550-560 nm, 696 nm, and NIR region
was highly correlated with corn plant N concentration at V9;
SPAD meter readings and GreenSeeker NDVI data had the
highest and lowest correlation coefficients with corn plant N
concentration, respectively;
Hyperspectral aerial remote sensing has a good potential to
monitor spatial corn N variation, and identify N deficiency
at V9, especially in corn-corn rotation fields;
SR7 and NDI2 were promising indices for N deficiency
identification and deserve further testing.