0

Looking at the aggregated nitrogen data from soilgrids (https://files.isric.org/soilgrids/latest/data_aggregated/5000m/nitrogen/nitrogen_0-5cm_mean_5000.tif), the values from the raster seem to range from 0 to ~20000.

This seems to correspond with the values on the soildgrids website given in the mapped units (cg/kg) multiplied by the conversion factor of 100 (given here: https://www.isric.org/explore/soilgrids/faq-soilgrids#What_do_the_filename_codes_mean), which would mean the values are given in the raster in (cg/100kg). However, according to the FAQ "By dividing the predictions values by the values in the Conversion factor column, the user can obtain the more familiar units in the Conventional units column". So the values given in the raster divided by 100 should give values in (g/kg) (i.e. the conventional units), whereas here it appears that dividing by 100 gives the values in (cg/kg) (i.e. the mapped units).

In contrast, the OCS data (https://files.isric.org/soilgrids/latest/data_aggregated/5000m/ocs/ocs_0-30cm_mean_5000.tif) appears to range from 0 - ~160, which corresponds to the values given in the mapped units (t/ha).

I'm not sure if this is an error on my part of if there's something I'm misunderstanding, but if anyone could enlighten me that'd be great.

1 Answer 1

1

There was an error in the data that was recently fixed. Now the values should align with the given units. Try to download the .tif again (same location)

2
  • Great, thanks! The nitrogen raster values are within expected bounds now. Do you know if this error affected other variables? I notice that a lot of the other rasters were also modified on 02 Jun 2022
    – A. Bollans
    Commented Jun 8, 2022 at 10:21
  • According to my version controlling, once I've processed the ph, nitrogen, ocs and soc rasters they are different to before; it it is likely all these were modified recently.
    – A. Bollans
    Commented Jun 8, 2022 at 10:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.