Veris Technologies OpticMapper - Application Note - Manual (Page 3)

Figure 4. Mapping at a slight angle to main fieldwork pattern
Note: Inaccurate estimations of organic matter due to soil moisture conditions
can have serious consequences for applications of nitrogen and population.
3. OM differences due to field history.
It’s reasonable to expect fields with different
histories that have been merged to have an actual shift in reflectance and OM.
Differences within merged fields can be due to manuring history, silage production,
long-term no-till, years since native sod, and other factors. In order to develop high-
quality calibrations to organic matter, make sure fields are thoroughly represented with
calibration samples, especially if smaller fields have been combined into larger fields.
4. Map field using these guidelines:
-use 50-
75’ transects
-if field has been cropped differently within past year, map each cropping area
separately
- don’t adjust depth or down pressure in field; start new file if you do
-drive at slight angle to predominate field traffic pattern if possible; this should eliminate
streaks/strips, and will help isolate cause if they occur