Soil Classification

Source: vignettes/Norwegian_Soil_Classification.Rmd

Author: Moritz Shore

Date: November, 2022

Introduction

Classifies soils based off of clay, silt, sand fractions using USDA (Ditzler, Scheffe, & Monger, 2017) or Norwegian (Sveistrup & Njøs, 1984) systems.

Figure 1: Soil classificatio based on the Norwegian (left) and USDA (right) systems.

Figure 1: Soil classificatio based on the Norwegian (left) and USDA (right) systems.

The function has the following features:

  • Automatically Compatible with csv or xlsx. Tries to automatically guess format of data, and acts accordingly.

  • Automatically rounds total fraction to 100%, if differences are under 1%.

  • Exports classification based on user settings

  • Creates an interactive diagnostic plot, as well as saving one to output directory.

Note: the script will automatically try to identify which columns contain the clay, silt, sand fractions and also try to identify which format they are in. If this does not work, you might get incorrect or flawed results, so make sure to READ what THE CONSOLE prints out, to make sure it did the correct things. If the script cannot read your file automatically, then the following format is recommended:

  • Clay column: “clay” in percent format (%), decimal = “.”
  • Silt column: “silt” in format (%), decimal = “.”
  • Sand column: “sand” in percent format (%), decimal = “.”

Usage

A simple usage is shown below. for a more in-depth run down of the arguments please visit the function help page.


# for demonstration purposes, use path of package
example_file_path <- system.file(package = "miljotools", "/extdata/soil_classify/example.csv")

classify_soil(
  input = example_file_path,
  output = "output_file.csv",
  version = "NOR",
  plot_result = T,
  interactive = FALSE,
  decimal = ".",
  write = FALSE # false just for demonstration. 
)
#> Identifying column:  sand 
#> sand  column identified as ' sand ' index= 3 
#> > mean value of  sand  column is  25  
#> Assuming values are in PERCENT form. ie. 43.1% (instead of 0.431)
#> Identifying column:  silt 
#> silt  column identified as ' silt ' index= 4 
#> > mean value of  silt  column is  23.1  
#> Assuming values are in PERCENT form. ie. 43.1% (instead of 0.431)
#> Identifying column:  clay 
#> clay  column identified as ' clay ' index= 2 
#> > mean value of  clay  column is  51.9  
#> Assuming values are in PERCENT form. ie. 43.1% (instead of 0.431)
#> 
#> 
#>  Checking for fraction sums over 100 %:
#> >  0  entries have a fractional sum of over 100.
#> >  0  entries have a fractional sum of under 100.
#>  adjusting the sand fraction and rounding...
#> 
#> > classifiying NORWEGIAN textures

#> [1] "C:/Users/mosh/Documents/GIT/miljotools/vignettes/output_file.csv"

References

Ditzler, C., Scheffe, K., & Monger, H. (2017). Soil survey manual: Soil science division staff. Goverment Printing Office: Washington, DC, USA.
Sveistrup, T., & Njøs, A. (1984). Kornstørrelsesgrupper i mineraljord. Revidert forslag til klassifisering. Det Norske Jord-og Myrselskap.