# compressive_properties: Estimation of compressive properties by Defossez et al.... In soilphysics: Soil Physical Analysis

## Description

It calculates the compressive parameters N and lambda using the pedo-transfer function from Defossez et al. (2003)

## Usage

 ```1 2``` ``` compressive_properties(water.content, soil=c("Loess", "Calcareous")) ```

## Arguments

 `water.content` a numeric vector containing the values of gravimetric water content, \% `soil` the soil group 'Loess' or 'Calcareous'. See examples

## Details

In Defossez et al. (2003), the recompression index, kappa, was assumed as 0.0058 for both soil group.

## Value

 `N` the specific volume at p = 1 kPa, N `CI` the compression index, lambda

## Author(s)

Renato Paiva de Lima <renato_agro_@hotmail.com> Anderson Rodrigo da Silva <anderson.agro@hotmail.com>

## References

Defossez, P., Richard, G., Boizard, H., & O'Sullivan, M. F., 2003. Modeling change in soil compaction due to agricultural traffic as function of soil water content. Geoderma, 116: 89–105.

`stressTraffic`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22``` ```# EXAMPLE 1 - For Loess and Calcareous soil water.content <- 25 compressive_properties(water.content=water.content, soil="Loess") compressive_properties(water.content=water.content, soil="Calcareous") # EXAMPLE 2 - For Loess soil water.content <- seq(from=5,to=30,len=20) out <- compressive_properties(water.content=water.content, soil="Loess") plot(x=water.content ,y=out\$N, ylab="N", xlab="Bulk density") # plot for N plot(x=water.content ,y=out\$CI, ylab="Lambda", xlab="Bulk density") # plot for compression index # EXAMPLE 3 - For Calcareous soil water.content <- seq(from=5,to=30,len=20) out <- compressive_properties(water.content=water.content, soil="Calcareous") plot(x=water.content ,y=out\$N, ylab="N", xlab="Bulk density") # plot for N plot(x=water.content ,y=out\$CI, ylab="Lambda", xlab="Bulk density") # plot for compression index # End (not run) ```