Download Topcon, Crop Spec, A Collaborative Partnership

Crop Spec,
A Collaborative Partnership
A real time integrated plant nutrient
monitoring and application system for
Agricultural equipment
Yara Electronic Products ,1995 - Present
CropSpecTM – specifications
Environment
IP 67 compliant
Laser safety
Class 1 or Class 1M
Physical Dimensions
200 mm x 80 mm x 80 mm
Mounting height
2 - 4 meters
Viewing angle
45°- 55°
Temperature
0 - 60°Celsius
Operational wavebands
735nm and 808 nm +/- 3nm
Supply voltage
10-32 VDC
Supply current
1A
Sensor Footprint – Oblique View
Impact of different N supply on the
reflectance spectra of winter wheat
Reflectance
0,6
N Supply
Increase due to
increased biomass
200 kg/ha
0,5
120 kg/ha
0,4
60 kg/ha
0,3
N response trail, 1994
0,2
Decrease due to increased
chlorophyll content
0,1
0
450
IR
500
550
600
650
700
750
800
850
Wavelength, nm
IR

N status of crops can be measured by analysing reflectance spectral data => nondestructive, non-contacting
Waveband to Chlorophyll relationship
The basis for getting meaningful crop information
• accurate measurements in various crops and
over a wide range of crop densities
• based on know-how and extensive field trial work by Yara
• 730-740 nm & 760-810 nm
1000
0.8
900
Wavelength 2 /nm
0.7
0.6
800
0.5
700
0.4
0.3
600
optimum waveband
combination
0.2
r2 values
for the correlation
between
measurements using
respective waveband
combinations and crop
characteristics
(e.g. crop biomass,
N-uptake)
0.1
500
0
400
400
500
600
700
800
Wavelength 1 /nm
900
1000
Source: Reusch, 2005
Crop Spec System Diagram for X20
RS232
Topcon X20
Supports all X20 application controllers
CANBUS
Implement with Liquid or
Granular Application
CropSpec Parameter Calculation
Define:
R = Simple ratio of NIR reflectance (808nm) to RedEdge (735nm)
R = NIR/ RedEdge
Define:
S1 = 100 * (R – 1)
Compare NDVI = (R - 1) / (R + 1)
The CropSpec parameter is defined:
S1CAL = 47 * S1 / S1REF
S1REF is the S1 measured with the reference matching filter.
The 47 factor is used for matching with YARA.
X20 CropSpec User Interface – Maplink
CropSpec
(S1CAL)
Histogram
CropSpec OTG Application Models
Negative slope factor also available
OTG Two Point Cal – Strip method
Drive Strip and Apply at Normal Rate
Select min and max CropSpec from
cutoff line
Associate two rates => slope factor
Select two point or target rate mode