criticalmoisture: Critical Moisture and Maximum Bulk Density
In soilphysics: Soil Physical Analysis

Description Usage Arguments Details Value Note Author(s) References See Also Examples

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.

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

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

`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.

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

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.

maxbulkdensity is just an alias of criticalmoisture.

Anderson Rodrigo da Silva <anderson.agro@hotmail.com>

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.

maxcurv

# 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)

Loading required package: rpanel
Loading required package: tcltk
Package `rpanel', version 1.1-4: type help(rpanel) for summary information
Loading required package: MASS
Loading required package: tkrplot
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soilphysics version 3.1

Warning messages:
1: no DISPLAY variable so Tk is not available 
2: loading Rplot failed 

          Critical Moisture and Maximum Bulk Density 

                  Sample 1
Intercept        0.4825950
mois            26.9265767
mois^2        -123.7120431
R.squared        0.9515476
n                5.0000000
critical.mois    0.1088276
max.bulk         1.9477727

          Critical Moisture and Maximum Bulk Density 

                 Sample s1    Sample s2    Sample s3    Sample s4
Intercept       -1.7284918    0.1224773    0.5377226    0.1182260
MOIS            65.8586240   33.0558707   26.0567222   34.9252102
MOIS^2        -292.5756113 -151.1627178 -122.1487135 -168.2393988
R.squared        0.7268508    0.9894252    0.8313948    0.8728340
n                5.0000000    5.0000000    5.0000000    5.0000000
critical.mois    0.1125498    0.1093387    0.1066598    0.1037962
max.bulk         1.9776940    1.9296203    1.9273254    1.9307775