soilphysics (version 2.1)

criticalmoisture: Critical Moisture and Maximum Bulk Density

Description

Function to determine the soil Critical Moisture and the Maximum Bulk Density based on the Proctor (1933) compaction test. It estimates compaction curve by fitting a quadradtic regression model.

Usage

criticalmoisture(theta, Bd, samples = NULL, graph = TRUE, ...)

maxbulkdensity(theta, Bd, samples = NULL, graph = TRUE, ...)

Arguments

theta

a vector containing the soil moisture values.

Bd

a vector containing the the soil bulk density values.

samples

optional; a vector indicating the multiple samples. Default is NULL (one sample). See details.

graph

logical; if TRUE (default), the soil compaction curve is plotted.

...

further graphical arguments.

Value

• An object of class 'criticalmoisture', i.e., a matrix containing the quadratic model coefficients (rows 1 to 3), the R-squared (row 4), the sample size (row 5), the critical soil moisture (row 6) and the maximum bulk density (row 7), per sample.

Details

If samples is ispecified, then it must has the same length of theta and Bd.

References

Proctor, E. R. (1933). Design and construction of rolled earth dams. Eng. News Record, 3: 245-284, 286-289, 348-351, 372-376. Silva, A. P. et al. (2010). Indicadores da qualidade fisica do solo. In: Jong Van Lier, Q. (Ed). Fisica do solo. Vicosa (MG): Sociedade Brasileira de Ciencia do Solo. p.541-281.

See Also

maxcurv

Examples

# example 1 (1 sample)
mois <- c(0.083, 0.092, 0.108, 0.126, 0.135)
bulk <- c(1.86, 1.92, 1.95, 1.90, 1.87)
criticalmoisture(theta = mois, Bd = bulk)

# example 2 (4 samples)
data(bulkDensity)
attach(bulkDensity)
criticalmoisture(theta = MOIS, Bd = BULK, samples = Id)

# End (not run)