Default parameters for calculating soil properties from sand & clay content
Source:R/data.R
soil_class.RdDefault parameters for calculating soil properties from sand & clay content
Format
## `soil_class` A list with 26 entries:
- air.cond, h2o.cond, sand.cond, silt.cond, clay.cond
thermal conductivity, W m^-1 K^-1
- air.hcap, sand.hcap, silt.hcap, clay.hcap
heat capacity, J m^-3 K^-1
- kair, ksand, ksilt, kclay
relative conductivity factor
- fieldcp.K
hydraulic conductance at field capacity, mm day^-1
- grav
gravity acceleration, m s^-2
- soil.key
Abbreviations for each of 18 soil texture classes, e.g. "SiL", "LSa"
- soil.name
Names for 18 soil texture classes, e.g. "Sand", "Silty clay"
- soilcp.MPa
soil water potential when air-dry, MPa
- soilld.MPa
soil water potential at critical water content, MPa
- soilwp.MPa
soil water potential at wilting point, MPa
- stext.lines
list of 18 lists, each giving minimum and maximum sand/silt/clay contents for a soil texture class
- stext.polygon
list of 18 lists, each giving corner points in the soil texture triangle for a soil texture class
- texture
data frame with 13 rows and 21 columns, giving default parameter values for 13 named soil textures
- theta.crit
critical water content (fractional soil moisture at which plants start dropping leaves), m^3 m^-3
- xclay.def
default volume fraction of sand in each of 18 soil texture classes
- xsand.def
default volume fraction of clay in each of 18 soil texture classes
Source
The hydraulic parameters are derived from Cosby et al 1984, "A Statistical Exploration of the Relationships of Soil Moisture Characteristics to the Physical Properties of Soils", Water Resources Research 20(6): 682-690. This implementation comes from one provided by the ED2 model, plus `texture.csv` from a source not recorded. Package `PEcAn.linkages` contains an identical texture.csv, also with no obvious source label. See also comments in soil_utils.R