OCSKGM: Soil organic carbon stock

In GSIF: Global Soil Information Facilities

Description

Derive soil organic carbon stock / storage (in kilograms per square-meter) and propagated uncertainty for a given horizon/solum depth and based on soil organic carbon concentration, horizon/solum thickness, bulk density and percentage of coarse fragments.

Usage

OCSKGM(ORCDRC, BLD=1400, CRFVOL=0, HSIZE, 
     ORCDRC.sd=10, BLD.sd=100, CRFVOL.sd=5, se.prop=TRUE)

Arguments

ORCDRC	numeric; soil organic carbon concentration in permille or g / kg
BLD	numeric; bulk density in kg / cubic-meter for the horizon/solum
CRFVOL	numeric; percentage of coarse fragments (above 2 mm in diameter) in the sample
HSIZE	numeric; thickness of the horizon/solum in cm
ORCDRC.sd	numeric; standard error of estimating ORCDRC (must be positive number)
BLD.sd	numeric; standard error of estimating BLD (must be positive number
CRFVOL.sd	numeric; standard error of estimating CRFVOL (must be positive number)
se.prop	logical; specifies whether to derive propagated error

Value

Soil organic carbon stock in kilograms per square-meter. To convert to tonnes per hectar multiply by 10.

Note

Propagated error (attached as an attribute) is estimated using the Taylor Series Method and shows only an approximate estimate. A more robust way to estimate the propagated uncertainty would be to use (geo)statistical simulations. See Heuvelink (1998) for more info.

Author(s)

Tomislav Hengl, Niels Batjes and Gerard Heuvelink

References

• Heuvelink, G. B. (1998) Error propagation in environmental modelling with GIS. CRC Press, 150 p.

• Nelson, D.W., and L.E. Sommers (1982) Total carbon, organic carbon, and organic matter. p. 539-580. In A.L. Page et al. (ed.) Methods of soil Analysis. Part 2. 2nd ed. Agron. Monogr. 9. ASA and SSSA, Madison, WI.

Examples

Area <- 1E4  ## 1 ha
HSIZE <- 30 ## 0--30 cm
ORCDRC <- 50  ## 5%
ORCDRC.sd <- 10  ## +/-1%
BLD <- 1500  ## 1.5 tonnes per cubic meter
BLD.sd <- 100  ## +/-0.1 tonnes per cubic meter
CRFVOL <- 10  ## 10%
CRFVOL.sd <- 5  ## +/-5%         
x <- OCSKGM(ORCDRC, BLD, CRFVOL, HSIZE, ORCDRC.sd, BLD.sd, CRFVOL.sd)
x  ## 20.25 +/-4.41 kg/m^2
## in tonnes per ha:
x[[1]] * Area / 1000

GSIF documentation built on May 2, 2019, 5:44 p.m.