aggreg.stability {soilphysics}

Soil Aggregate-Size Distribution

Description

It calculates the mean weight diameter (MWD), the geometric mean diameter (GMD) and the soil aggregates size distribution per class based on the mass of the aggregates retained in each sieve from a total soil mass used for the soil aggregate stability test.

Usage

aggreg.stability(sample.id = NA, dm.classes, aggre.mass)

Arguments

sample.id

optional; a character vector containing the sample names.

dm.classes

a numeric vector containing the aggregates classes, in mm.

aggre.mass

a data.frame consisting of columns with soil aggregates mass (g) of each one of the corresponding dm.classes.

Details

The user must arrange a data.frame with lines representing the samples and the columns representing the mass of the aggregates retained in each one of the meshes (corresponding to each size class) in the aggregate stability test.

Value

A data.frame containing valor of MWD, GMD, total soil mass (total.mass) used in the aggregate stability test and the percentage of soil aggregate size distribution per class.

Author(s)

Renato Paiva de Lima <[e-mail]>

References

W. Kemper, W. Chepil. (1965). Size distribution of aggregates. C. Black (Ed.). Methods of Soil Analysis, American Society Agronomy, Madison. pp. 499-510.

Yoder, R. A. (1936). A direct method of aggregate analysis of soils and a study of the physical nature of erosion losses. Journal of the American Society of Agronomy, 28:337-351.

Examples

data(SoilAggregate)
classes <- c(3, 1.5, 0.75, 0.375, 0.178, 0.053)
aggreg.stability(sample.id = SoilAggregate[ ,1],
   dm.classes = classes, aggre.mass = SoilAggregate[ ,-1])

# End (not run)