1. Crop Spec, A Collaborative Partnership
A real time integrated plant nutrient monitoring and application system for Agricultural equipment

2. Yara Electronic Products ,1995 - Present

3. 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
1 A

4. Sensor Footprint – Oblique View

5. Decrease due to increased
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 IR
450
500
550
600
650
700
750
800
850
Wavelength, nm IR
N status of crops can be measured by analysing reflectance spectral data => non-destructive, non-contacting

6. 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
nm & nm
Source: Reusch, 2005

7. Crop Spec System Diagram for X20
RS232
CANBUS
Topcon X20
Implement with Liquid or Granular Application
Supports all X20 application controllers

8. CropSpec Parameter Calculation
Define:
R = Simple ratio of NIR reflectance (808nm) to RedEdge (735nm)
R = NIR/ RedEdge
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.

9. X20 CropSpec User Interface – Maplink
CropSpec (S1CAL)
Histogram

10. CropSpec OTG Application Models
Negative slope factor also available

11. 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