Wolfram Function Repository

Instant-use add-on functions for the Wolfram Language

Function Repository Resource:

 SoilTexturePlot

Source Notebook

Visually classify soil sample types by their relative sand, silt and clay contents

Contributed by: Phileas Dazeley-Gaist

ResourceFunction["SoilTexturePlot"][]

plots the standard USDA soil texture diagram.

ResourceFunction["SoilTexturePlot"][samples]

plots a soil texture diagram overlaid with points samples, with soil samples provided in the format {sand,clay,silt}.

Details and Options

ResourceFunction["SoilTexturePlot"] visually classifies soil samples into the classes: "Silt", "Silty clay loam", "Silty clay", "Silt loam", "Clay loam", "Loam", "Sandy clay", "Sandy clay loam", "Sandy loam", "Loamy sand", "Sand" and "Clay".
Soil samples must be entered in the format {sand,clay,silt}, where each element of the list represents the relative quantities of sand, clay and silt found in each sample.
Soil samples must be provided in a list: {sample1, sample2,…}.
Soil typeRGB values
"Silt"{0,256,0}
"Silty clay loam"{37,204,135}
"Silty clay"{106,256,191}
"Silt loam"{126,203,0}
"Clay loam"{181,256,48}
"Loam"{206,137,0}
"Sandy clay"{256,0,0}
"Sandy clay loam"{256,128,136}
"Sandy loam"{256,189,256}
"Loamy sand"{256,191,195}
"Sand"{256,193,131}
"Clay"{256,256,125}

Examples

Basic Examples (3) 

Plot the standard USDA soil texture diagram:

In[1]:=
ResourceFunction["SoilTexturePlot"][]
Out[1]=

Visually classify a single soil sample with the given relative quantities on the soil texture diagram:

In[2]:=
ResourceFunction["SoilTexturePlot"][{1, 2, 3}]
Out[2]=

Overlay soil samples on the soil texture diagram:

In[3]:=
ResourceFunction["SoilTexturePlot"][{ {(*Sand:*).3,(*Clay:*).3,(*Silt:*).4}, {0.38`, 0.16`, 0.46`}, {0.69, 0.17, 0.14}, {0.17, 0.53, 0.31}, {0.25, 0.36, 0.39}}]
Out[3]=

Options (7) 

GridLines (3) 

By default, the diagram is plotted with grid lines (GridLines→True):

In[4]:=
ResourceFunction["SoilTexturePlot"][]
Out[4]=

Plot the soil texture diagram without grid lines:

In[5]:=
ResourceFunction["SoilTexturePlot"][GridLines -> False]
Out[5]=

Plot the soil texture diagram with custom grid lines, following the grid line specification conventions of TernaryListPlot:

In[6]:=
ResourceFunction["SoilTexturePlot"][GridLines -> { {{0.`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}, {0.2`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}, {0.4`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}, {0.6`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}, {0.8`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}, {1.`, Opacity[0.5`, RGBColor[0.14, 0.8, 0.14]]}}, {{0.`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}, {0.2`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}, {0.4`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}, {0.6`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}, {0.8`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}, {1.`, Opacity[0.5`, RGBColor[0.4, 0.6, 1]]}}, {{0.`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}, {0.2`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}, {0.4`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}, {0.6`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}, {0.8`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}, {1.`, Opacity[0.5`, RGBColor[0.93, 0.27, 0.27]]}} }]
Out[6]=

SoilTypeColors (4) 

Use a grayscale theme:

In[7]:=
ResourceFunction["SoilTexturePlot"]["SoilTypeColors" -> "Grayscale"]
Out[7]=

Recolor the region corresponding to a soil type on the plot:

In[8]:=
ResourceFunction["SoilTexturePlot"][ "SoilTypeColors" -> <|"Clay" -> Lighter[Orange, .5]|>]
Out[8]=

Recolor all soil type regions:

In[9]:=
ResourceFunction["SoilTexturePlot"][ "SoilTypeColors" -> <|"Silt" -> RGBColor[ 0.2823529411764706, 0.22745098039215686`, 0.2235294117647059], "Silty clay loam" -> RGBColor[ 0.5647058823529412, 0.23137254901960785`, 0.15294117647058825`], "Silty clay" -> RGBColor[ 0.6392156862745098, 0.39215686274509803`, 0.3333333333333333], "Silt loam" -> RGBColor[ 0.8627450980392157, 0.6196078431372549, 0.2627450980392157], "Clay loam" -> RGBColor[ 0.9647058823529412, 0.788235294117647, 0.5254901960784314], "Loam" -> RGBColor[ 0.4588235294117647, 0.592156862745098, 0.4627450980392157], "Sandy clay" -> RGBColor[ 0.23921568627450981`, 0.45098039215686275`, 0.24705882352941178`], "Sandy clay loam" -> RGBColor[ 0.34509803921568627`, 0.5803921568627451, 0.6901960784313725], "Sandy loam" -> RGBColor[ 0.1843137254901961, 0.39215686274509803`, 0.49019607843137253`], "Loamy sand" -> RGBColor[ 0.5686274509803921, 0.7490196078431373, 0.8431372549019608], "Sand" -> RGBColor[ 0.2823529411764706, 0.22745098039215686`, 0.2235294117647059], "Clay" -> RGBColor[ 0.5647058823529412, 0.23137254901960785`, 0.15294117647058825`]|>]
Out[9]=

Recolor soil type regions using a function:

In[10]:=
ResourceFunction["SoilTexturePlot"]["SoilTypeColors" -> With[ {soilTypes = {"Silt", "Silty clay loam", "Silty clay", "Silt loam", "Clay loam", "Loam", "Sandy clay", "Sandy clay loam", "Sandy loam", "Loamy sand", "Sand", "Clay"}}, AssociationMap[ Which[ MatchQ[#, Alternatives @@ Select[soilTypes, StringContainsQ[#, "Silt"] &]], Lighter[StandardOrange, .5], MatchQ[#, Alternatives @@ Select[soilTypes, StringContainsQ[#, "Sand"] &]], Lighter[StandardYellow, .5], MatchQ[#, Alternatives @@ Select[soilTypes, StringContainsQ[#, "Clay"] &]], Lighter[Brown, .5], True, Darker[StandardBrown]] &, soilTypes]]]
Out[10]=

Applications (2) 

Visualize the classification of soil sand, clay, and silt composition samples:

In[11]:=
sample = RandomReal[{0, 1}, {100, 3}];
In[12]:=
ResourceFunction["SoilTexturePlot"][sample]
Out[12]=

Study samples from parametric distributions:

In[13]:=
sample = With[{ nSamples = 100, sandDist = NormalDistribution[1, .25], clayDist = NormalDistribution[2, .5], siltDist = NormalDistribution[3.5, 1] }, Thread[{ RandomVariate[sandDist, nSamples], RandomVariate[clayDist, nSamples], RandomVariate[siltDist, nSamples] }] ];
In[14]:=
ResourceFunction["SoilTexturePlot"][sample]
Out[14]=

Possible Issues (1) 

Negative samples can invalidate results:

In[15]:=
ResourceFunction["SoilTexturePlot"][{1, -1, 0}]
Out[15]=

Publisher

Phileas Dazeley-Gaist

Version History

  • 1.0.0 – 25 March 2026

Source Metadata

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