criticalmoisture: Critical Moisture and Maximum Bulk Density

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

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

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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.

Details

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

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.

Note

maxbulkdensity is just an alias of criticalmoisture.

Author(s)

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

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

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# 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)

Example output

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
---
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

soilphysics documentation built on Jan. 13, 2021, 7:06 p.m.