Soil texture

Soil texture for GRASS.

r.soils.texture define soils texture from sand and clay distribution grid and a texture scheme definition. The sand and clay grid are simple grid theme; the scheme file is a text ASCII file with *.dat extension like USDA.dat, FAO.dat and international.dat, supplied with source code module in scheme directory; furthermore, you can download single files from the following link in GRASS 7 addons

Soil texture for QGIS.

The plugin require two raster: spatial distribution for sand and clay for the same area. The user must supply even the texture schema and the name of output file.

The user get two output files:

1. raster map, with the representation of single pixels coded with a unique texture value based on schema selected by the user;

2. vector map with the representation of homogeneous areas with the same texture type. The attribute table contain the texture code and the label based on schema selected from the user.

You can download example files for testing the module.

Input Clay distribution (%) Sand distribution (%)
Texture (raster output, USDA scheme) Texture (vector output, with labels from attribute table, USDA scheme)

The plugin supply even a text file, named "ternaryPlot.csv", saved in the same output directory. You can use this file in R with packages "soiltexture". Follow a sample code for plot in a ternary chart. More info are available on site: soiltexture: Functions for Soil Texture Plot, Classification and Transformation

#install soiltexture pakages,only firsth one time!

install.packages( pkgs = "soiltexture" )

#load soiltexture library

library( soiltexture )

#load file ternaryPlot.csv in dataframe

ternaryPlot <- read.csv("/your path/ternaryPlot.csv")

#plot data in ternary chart

TT.plot(class.sys= "USDA.TT", tri.data= ternaryPlot, main= "Soil texture data")

Overplotting two soil texture classification systems with the same geometry:

geo<-TT.plot(class.sys= "none", tri.data= ternaryPlot, main= "Soil texture data") TT.plot(geo=geo,class.sys="USDA.TT", add=TRUE)

August 15, 2015 by G. Massei