soil_texture {medfate}R Documentation

Soil texture and hydraulics

Description

Low-level functions relating soil texture with soil hydraulics and soil water content.

Usage

soil_saturatedConductivitySX(clay, sand, bd, om = NA_real_, mmol = TRUE)

soil_unsaturatedConductivitySX(
  theta,
  clay,
  sand,
  bd,
  om = NA_real_,
  mmol = TRUE
)

soil_thetaSATSX(clay, sand, om = NA_real_)

soil_theta2psiSX(clay, sand, theta, om = NA_real_)

soil_psi2thetaSX(clay, sand, psi, om = NA_real_)

soil_psi2kVG(ksat, n, alpha, theta_res, theta_sat, psi)

soil_psi2cVG(n, alpha, theta_res, theta_sat, psi)

soil_psi2thetaVG(n, alpha, theta_res, theta_sat, psi)

soil_theta2psiVG(n, alpha, theta_res, theta_sat, theta)

soil_USDAType(clay, sand)

soil_thetaFC(soil, model = "SX")

soil_thetaWP(soil, model = "SX")

soil_thetaSAT(soil, model = "SX")

soil_waterFC(soil, model = "SX")

soil_waterSAT(soil, model = "SX")

soil_waterWP(soil, model = "SX")

soil_waterPsi(soil, psi, model = "SX")

soil_waterExtractable(soil, model = "SX", minPsi = -5)

soil_theta(soil, model = "SX")

soil_water(soil, model = "SX")

soil_rockWeight2Volume(pWeight, bulkDensity, rockDensity = 2.3)

soil_psi(soil, model = "SX")

soil_conductivity(soil, model = "SX")

soil_capacitance(soil, model = "SX")

soil_saturatedWaterDepth(soil, model = "SX")

soil_vanGenuchtenParamsCarsel(soilType)

soil_campbellParamsClappHornberger(soilType)

soil_vanGenuchtenParamsToth(clay, sand, om, bd, topsoil)

soil_retentionCurvePlot(
  soil,
  model = "SX",
  layer = 1,
  psi = seq(0, -6, by = -0.01),
  relative = TRUE,
  to = "SAT"
)

Arguments

clay

Percentage of clay (in percent weight).

sand

Percentage of sand (in percent weight).

bd

Bulk density (in g/cm3).

om

Percentage of organic matter (optional, in percent weight).

mmol

Boolean flag to indicate that saturated conductivity units should be returned in mmol/m/s/MPa. If mmol = FALSE then units are cm/day.

theta

Relative water content (in percent volume).

psi

Water potential (in MPa).

ksat

saturated hydraulic conductance

n, alpha, theta_res, theta_sat

Parameters of the Van Genuchten-Mualem model (m = 1 - 1/n).

soil

Initialized soil object (returned by function soil).

model

Either 'SX' or 'VG' for Saxton's or Van Genuchten's water retention models; or 'both' to plot both retention models.

minPsi

Minimum water potential (in MPa) to calculate the amount of extractable water.

pWeight

Percentage of corresponding to rocks, in weight.

bulkDensity

Bulk density of the soil fraction (g/cm3).

rockDensity

Rock density (g/cm3).

soilType

A string indicating the soil type.

topsoil

A boolean flag to indicate topsoil layer.

layer

Soil layer to be plotted.

relative

Boolean flag to indicate that retention curve should be relative to field capacity or saturation.

to

Either 'SAT' (saturation) or 'FC' (field capacity).

Details

Value

Depends on the function (see details).

Author(s)

Miquel De Cáceres Ainsa, CREAF

References

Leij, F.J., Alves, W.J., Genuchten, M.T. Van, Williams, J.R., 1996. The UNSODA Unsaturated Soil Hydraulic Database User’s Manual Version 1.0.

Saxton, K.E., Rawls, W.J., Romberger, J.S., Papendick, R.I., 1986. Estimating generalized soil-water characteristics from texture. Soil Sci. Soc. Am. J. 50, 1031–1036.

Saxton, K.E., Rawls, W.J., 2006. Soil water characteristic estimates by texture and organic matter for hydrologic solutions. Soil Sci. Soc. Am. J. 70, 1569. doi:10.2136/sssaj2005.0117

Wösten, J.H.M., & van Genuchten, M.T. 1988. Using texture and other soil properties to predict the unsaturated soil hydraulic functions. Soil Science Society of America Journal 52: 1762–1770.

Tóth, B., Weynants, M., Nemes, A., Makó, A., Bilas, G., and Tóth, G. 2015. New generation of hydraulic pedotransfer functions for Europe. European Journal of Soil Science 66: 226–238.

See Also

soil

Examples

#Determine USDA soil texture type
type = soil_USDAType(clay=40, sand=10)
type

#Van Genuchten's params (bulk density = 1.3 g/cm)
vg = soil_vanGenuchtenParamsToth(40,10,1,1.3,TRUE)
vg

# Define soil with default params
soil_df <- defaultSoilParams(4)
soil_df

# Initialize soil parameters and state variables
s = soil(soil_df)

# Plot Saxton's and Van Genuchten's water retention curves
soil_retentionCurvePlot(s, model="both")


[Package medfate version 4.8.1 Index]