envalysis (version 0.5.5)

texture: ASTM soil texture analysis

Description

Calculates the particle size distribution and both DIN and USDA texture classes from a series of hydrometer readings according to ASTM D422-63 (2007).

Usage

texture(reading, ...)
# S3 method for formula
texture(formula, data = NULL, ...)
# S3 method for default
texture(
  reading,
  blank,
  time,
  temp,
  conc = 50,
  Gs = 2.65,
  hydrometer = "auto",
  model = "auto",
  plot = F,
  ...
)
# S3 method for texture
print(x, ...)
# S3 method for texture
plot(x, ...)

Value

texture returns an object of class 'texture. The functions print() and plot() are available to retrieve the soil texture classes and the particle size distribution, respectively.

An object of class 'texture' is a list containing the following components:

meta	Measurement meta data
distribution	data frame providing the particle size distribution
model	information on the fitted drm model
din	Main DIN texture classes
usda	Main USDA texture classes

Arguments

reading

a numeric vector of data values providing the hydrometer readings at the bottom of the meniscus.

...

further arguments to be passed to texture() (currently not used), print(), or plot().

formula

an object of class 'formula' of the form reading ~ blank + time + temp.

data

a data frame containing the variables in formula.

blank

a numeric vector containing the blank readings taken in 5 g/L sodium hexametaphosphate solution (composite correction).

time

a numeric vector containing the time passed since the beginning of the measurement in minutes.

temp

an integer vector containing the measured temperature.

conc

the concentration of the soil solution, default is 50 g/L as proposed in the ASTM guideline.

Gs

specific gravity of the suspension.

hydrometer

a character string specifying the hydrometer used; accepted values are "auto" for auto-detection (default), "151H", and "152H".

model

string is passed to drm(), "auto" chooses the best fitting model automatically.

plot

logical; if TRUE the particle size distribution is plotted.

x

an object of class 'texture'.

Author

Zacharias Steinmetz

References

ASTM D422-63 (2007). Standard Test Method for Particle-Size Analysis of Soils. Technical standard. ASTM International, West Conshohocken, PA. Available from https://www.astm.org/standards/d422.

See Also

Other texture: clayloam

Examples

data(clayloam)
texture(reading ~ blank + time + temperature, clayloam)