Spectral Sensors by Carl Zeiss

Measuring Crop Plant Quality in the Field

INTRODUCTION
For the short period between harvesting and the next
sowing, plant breeders need rapid, cost-effective andmeaningful analytical techniques to be able to develop
crop plants with improved quality. The advances
achieved obtained in, for example, the dry matter
content of forage grass, the oil content of oilseed rapeand the protein content of feed barley depend directlyon the intensity of selection from a starting material
which consists of thousands of foundation stocks.
Instead of conventional „wet chemical“ analyticalprocedures, spectroscopy in the near infrared (NIRS)
has proved to be successful for this purpose and can
now be transferred from the laboratory to the field as aconsequence of newly developed instruments.

Fig.1 MMS NIR

THE METHOD

Fig.2 Forage harvester from the company Haldrup (Denmark).
0,7fresh grass
0,6

Absorption (Log 1/R)

The water content of field crops determines theirstability during storage, partially characterizes theirnutritional value and is also a crucial factor in fixing
their trading price. Water is the constituent which canbe most easily determined in the near infrared Whileother constituents of economic importance such asprotein, oil and carbohydrates display lower
absorptivity in the near infrared , their contents cannonetheless be determined with high analyticalprecision by a single, non-destructive measurement offreshly harvested grains and seeds.

0,5

0,4

0,3

0,2

0,1
dry grass
0,0
960

1028

1101

1173

1245

1318

1390

1462

1534

1607

1679

Wavelength (nm)Fig.3 Absorption spectra of grass with different
levels of moisture.

Application Note 6 / 9 9

Spectral Sensors by Carl Zeiss

THE SYSTEM
On the basis of the equipment devised and the chemometric research carried out by Norris in the USA, spectroscopy in
the near infrared (NIR) has now made its way into plant cultivation. So far, however, the current status of the NIRS
instrument technology has limited this analytical procedure to stationary use in the laboratory. The availability of diodearrays for the spectral range of the near infrared now makes it possible to the use NIRS directly on agricultural harvest
machines. The company Carl Zeiss, the Danish agricultural engineering company Haldrup and the Institute of Crop andGrassland Science of the German Federal Agricultural Research Center have jointly developed a forage harvester fortrial plots which allows NIRS measurements on representative samples of the crop during harvesting. The CORONANIR sensor module installed in the harvester is based on the MMS-NIR 1.7 diode array spectrometer (Fig. 1) and has
been specially designed for the rough conditions of field use.
The particular benefits of the CORONA NIR result from the high measuring speed of the MMS-NIR 1.7, its hightemperature stability, small size and total insensitivity to vibrations and shock. These features clearly distinguish thisunit from the NIR measuring instruments used in the laboratory which are unsuitable for mobile use in the roughconditions of field cropping, not only because of their slow measuring speed but also because of their moving, shocksensitive gratings or filter wheels required for the dispersion of polychromatic light. In the summer of 1999, the first
Haldrup forage harvesters of the new „NIRS harvest line“ for such forage plants as grass and clover were purchased by
the German plant breeding companies Deutsche Saatveredelung (DSV) and Norddeutsche Pflanzenzucht (NPZ) andtested in the field (Fig. 2). The chemometric calibration of the sensor in field conditions is being continued together withthese plant breeding companies. In addition, a combine harvester equipped with a CORONA NIR will be available forsuch grain crops as cereals, oil seeds and grain legumes for the first time in the year 2000.
The integration of NIR diode array spectrometers in agricultural combine harvesters will initially increase the efficacy ofplant breeding and testing aimed at creating cultivars with improved properties. In addition, it should not be overlookedthat this type of „mobile analysis” can also be transferred to practical agriculture where a wide variety of approaches toso-called „precision farming” are increasingly being tested. Thus, the NIR diode array spectrometers could one day
make an effective contribution to quality assurance in environmentally compatible plant production.

Autors:Dr. Christian Paul and Michael Rode work at the Institute of Crop and Grassland Science of the German Federal
Agricultural Research Center (FAL), Bundesallee 50 in 38116 Braunschweig/Germany.

Carl Zeiss
Spektralsensorik

D-07740 Jena
Telefon:(03641)64 2838
Telefax:(03641)64 2485
E-Mail:info.spektralsensorik@zeiss.de
Internet:
http:// www.zeiss.deSpectral Sensors by Carl Zeiss

CORA - Software Package for Agriculture
and Food

CORA is a software program package speciallydesigned for the requirements of agriculture and foodprocessing. Its great ease of operation, data security,
data base administration, spectral manager and thepossibility of integrating a great variety of data make thispackage a top-of-the-line option in on-line, routine andfield analysis. Applications include monitoring GPS
coordinates, specimen temperature and different
chemometric calibration models.
Benefitsvvvv

New open software concept
Dual use: On-line and At-line
Extensive sample list management
Customizable operation, measurement, prediction
and output
v Multiple and expandable support of third-party
external equipment

CORONA sensor unit

CORA on-line

CORA LabCORA on-line

Data Exchange

Sample Lists
NIRS plots

Calibration
Models & Data

CORA on-line
Sample Lists
NIRS plots

GRAMS, …

CORA LabCORA at-line
Configuration for agriculture fields

Distributor US/Canada
45 John Street #908
New York, NY 10038-3706
Phone:
212.393.9540
Fax:
212.393.9538
email:
info@analyze.com

Spectral Sensors by Carl Zeiss

Dual use On-line and At-line
•
•
•
•
•
•
•

One touch / automatic operation
Active (switchable) display
Easy-to-read results & status indicators
Scrollable plot list
Multiple level password protection
Sample list management and processing
Future customizable options ....

Sample Lists - the central data collections
ASCII sample lists hold all information
•
•
•
•
•
•

Sample list

Origin: Station, Operator and Software
Measurement and Operation
Additional Measuring Devices
Prediction & Evaluation
Output Specifications
Plot File Names and Prediction Results

Sample lists can be...
•
•
•
•
•

Generated automatically in on-line mode
Checked and post-processed
Edited and transferred
Prepared at-line for on-line measurements
Customized (header tags)

Spectra Manager•••

Measurement & Operation settings

Management and processing of spectra
Visualization of spectra
Generation of filters for elimination of outliers

Customizing the Data Evaluation•••

Spectra Manager

Selection of calibration to be applied, produced fromdifferent analytical packages (GRAMS, ... )Enable / Disable prediction
Specification of several prediction values (results,
residuals ..) to be used as measurements results forselected data output

Customizing the Data Output

•
•
•
•

Spectrometer settings, interpolation and averaging
Adjustments for outlier detection & removal
Measurement trigger mode: wire, keyboard,
touch screen, time
Operational options include:timed, manual or
automatic calibration, active control of sample
processing equipment via dig. I/O

Setting up the Measuring Station••

Identification of measuring station and operator
Assignment, activation and setup of additional
measuring devices on this local station, e.g..
Scales, Plant counter, Barcode readers, Graincounters .....

Selectable data output options including:• Configurable ASCII tables• RS 232 on-line uni-directional data stream (string format
customizable)
Carl Zeiss
Spectral Sensors

D-07740 Jena
Telefon:++49 364164 33 85
Telefax:++49 364164 24 85
E-Mail:info.spektralsensorik@zeiss.de
Internet:
http://www.zeiss.de/spectral

Near Infrared Spectroscopy (NIRS)
Methods for the Assessment of Quality
in Fresh Forages
Michael Rode, Christian Paul
Institute for Grassland and Forage ResearchFederal Research Centre for Agriculture
Bundesallee 50
D - 38116 Braunschweig
GermanyOverview- Instrumentation- Material- Calibration Examples- Prospects

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

2Rode / GFF

Instrumentation

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

3Rode / GFFNIRSystems 6500
- Diffuse Reflectance /(Transmittance)- Wavelength range:
400 - 2500 nm- Scans per second:
1 Scan- Resolution:
2 nm- Wavelength accuracy:+/- 0,5 nm
Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

4Rode / GFF

Infratec Meat Analyzer- Transmittance- Wavelength range:
850 - 1050 nm- Scans per second:
1 Scan- Resolution:
2 nm

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

5Rode / GFF

Zeiss MMS-NIR 1.7- Diffuse Reflectance /(Transmittance)- Wavelength range:
945 - 1700 nm- Scans per second:
100 Scans- Resolution:
6 nm- Wavelength accuracy:+/- 0,6 nm
Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

6
Rode / GFF

Instruments / Sampling methods
DiffuseTransmission

Diffuse
Reflection

L igh t so u rce

Transflection with
Lightfibre
L igh tfib re

D e te cto r

C ons tructionprinciple

Sa m p le headS a m p leD etector:
λ - R ang e (n m) :Si
800 -1 050

Si + P bS
400 -2500

A rea(cm ²) :S can s / sec
:

3
~1

5
~1

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

InGa As
90 0-170 0(900-2 500)
5
~ 100

7
Rode / GFF

Material

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

8Rode / GFF

Grasses and Legumes- Grasses-

Lolium perenne
Lolium multiflorum
Dactylis glomerata
Festuca arundinacea- Legumes-

Trifolium repens
Trifolium pratense
Medicago sativa
Lotus corniculatus
Galega orientalis

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

9Rode / GFF

Calibration Examples

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

10
Rode / GFF

Spectral Differences between Dry andFresh Grass Samples
1,4

A b so r p tio n (L o g 1 /R)

1,2
fres h g ras s
1,0

0,8

0,6

0,4

0,2
dr y g ra ss
0,0
11 00

13 00

15 00

17 00

19 00

21 00

23 00

25 00

W a v e le n g th (n m )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

11
Rode / GFF

Difference Spectrum of Fresh
vs. Dry Grass
1,6

A b s o r p tio n (L o g 1 /R )

1,4

1,2

1
F re sh0,8Dry
D if fer en ce

0,6

0,4

0,2

0
1 10 01 30 0

1 500

1 700

19 00

21 00

230 0

250 0

W a ve le n g th (n m )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

12
Rode / GFF

Chemometric Software- WinISI II V1.0
- Global Calibrations- Regression types- Partial Least Squares (PLS)- Principle Component (PCR)- Step-up- Modified Stepwise (MSR)- Cross Validation- Local Calibrations- Neural Networks
Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

13
Rode / GFFExamples of Calibrations for Fresh and
Dry Grasses (NIRSystems and ZEISS)- Calibrations on the NIRSystems 6500
- Calibration Results with Fresh Forages- Comparison of Calibrations with Dry Samples on
NIRSystems 6500 vs. ZEISS MMS-NIR 1.7- Calibrating the portable ZEISS MMS-NIR 1.7- Regression Analysis of NIR Absorption vs. Dry
Matter Concentration in Fresh Grass on
NIRSystems 6500 vs. ZEISS MMS-NIR 1.7

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

14
Rode / GFF

Selection of Fresh Forage Calibrations
on the NIRSystems 6500: Results- Dry Matter DM %- Standard Error (SE): 1,13
- R2: 0,99

- Crude Protein CP (% of DM)- SE: 1,56
- R2: 0,92

- Water Soluble Carbohydrates WSC (% of DM)- SE: 0,88
- R2: 0,94
Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

15
Rode / GFF

Dry Matter Calibration of Fresh Forages(NIRSystems 6500)
60

D M % (p re d ic te d )

50

40

30

20

10

0
0

10

20

30

40

50

60

D M % (L ab )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

16
Rode / GFF

Protein Calibration of Fresh Forages(NIRSystems 6500)
30

C P % (pr ed ic ted )

25

20

15

10

5

0
0

5

10

15

20

25

30

C P % (La b )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

17
Rode / GFF

Carbohydrate Calibration of Fresh
Forages (NIRSystems 6500)
2018

W S C % (p r ed ic ted )

16
14
12
10
8
6
4
2
0
0

5

10

15

20

W SC % (L a b )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

18
Rode / GFF

Calibration Comparison of Dry Samples
on the NIRSystems and the ZEISS
Equalized Wavelength Range
958-1678 nm

NIRSystem s 6500

ZE ISS M M S-N IR

Constituentn (6500/M MS)

Range (% )Term sSE

Term sSE

Dry Matter

94 / 97

93,8 - 98,7

5

0,43

7

0,46

Crude Protein

92 / 94

8,7 - 23,7

8

0,52

8

0,57

Crude Ash

65 / 64

7,6 - 12,6

6

0,61

5

0,67

Crude Fibre

94 / 94

16,7 - 34,1

8

0,99

8

1,22

W SC

194 / 193

3,3 - 15,5

12

0,63

10

0,87

EULOS

93 / 93

116,5 - 388,3

8

15,99

8

19,21

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

19
Rode / GFF

Spectra of Fresh Grass with Different
Dry Matter on the NIRSystems 6500
1,0
fre sh gr as s
0,9

A b so r p tio n (L o g 1 /R)

0,8
0,7
0,6
0,5
0,4
dry g ras s

0,3
0,2
0,1
960

104 0

11 20

12 00

1 28 01 36 0

14 40

15 20

1 600

1 68 0W a v e le n g th (n m )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

20
Rode / GFF

Spectra of Fresh Grass with Different
Dry Matter on the ZEISS MMS-NIR 1.7
0,7
f res h gra ss

A b so r p tio n (L o g 1 /R)

0,6

0,5

0,4

0,3

0,2

0,1
d ry gra ss
0,0
96 0

1 02 8

1 101

11 73

124 5

1 31 8

1 390

14 62

15 34

1 60 7

1 67 9W a v e le n g th (n m )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

21
Rode / GFF

Dry Matter 1 - Term - Regression(NIRSystems 6500)
W av e le n g th : 1 5 82 n m
9080

D M % (p re d ic te d )

70
60
50
40
30
20
10
0
0

10

20

30

40

50

60

70

80

90

D M % (L ab )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

22
Rode / GFF

Dry Matter 1 - Term - Regression(ZEISS MMS-NIR 1.7)
W av e le n g th : 1 5 58 n m
9080

D M % (p re d ic te d )

70
60
50
40
30
20
10
0
0

10

20

30

40

50

60

70

80

90

D M % (L ab )Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

23
Rode / GFF

Prospects

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

24
Rode / GFF

Measurement and Data Handling- Construction of Instruments- Modular Construction- Portability / Ruggedness- Miniaturization- Data Point Standardization- Sample Presentation- in line / on line
- Reflectance / Transmittance- Size of Measurement Area
Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

25
Rode / GFF

Measurement and Data Handling- Standard Data Format- Transferability of Spectra- Identification Routines- Quantification Routines

Institute for Grassland and Forage Research (FAL)
Bundesallee 50, D - 38116 Braunschweig, Germany

26
Rode / GFF