Soil properties in SPAW

Wilting point, field capacity and saturated moisture

  • wilting point: 1500 kPa moisture, %v, (Eq. 1)

  • field capacity: 33 kPa moisture, %v, (Eq. 2)

  • saturated moisture: Saturation (0 kPa moisture), %v, (Eq. 5)

wilting_point(S, C, OM)

field_capacity(S, C, OM)

saturated_mois(S, C, OM)

wilting_point_salinity(S = 0.2, C = 0.2, OM = 2.5, EC = 3)

Arguments

S

the weight ratio of Sand, (weight ratio, 0-1)

C

the weight ratio of Clay, (weight ratio, 0-1)

OM

the percentage of Organic Matter, (%w, 0-100)

EC

Electrical conductance of a saturated soil extract (dS/m = mili-mho/cm)

Value

%v

Note

The unit of OM is %w, which is different from S and C.

References

  1. Saxton, K. E., & Rawls, W. J. (2006). Soil water characteristic estimates by texture and organic matter for hydrologic solutions. Soil Science Society of America Journal, 70(5), 1569-1578. doi:10.2136/sssaj2005.0117

Examples

S = C = 0.20; OM = 2.5 
wilting_point(S, C, OM)  # 13.8%
#> [1] 0.1365448
field_capacity(S, C, OM) # 32.1% 
#> [1] 0.3208775
saturated_mois(S, C, OM) # 48.2%
#> [1] 0.482125