soil_cover {SoilManageR} | R Documentation |
Estimate soil cover by plants and residues
Description
Derives the days where soil cover by living plants or resiudes is >=30%
.
Usage
soil_cover(var_MGMT_data, extended.output = FALSE)
Arguments
var_MGMT_data |
a |
extended.output |
an optional logical value.
|
Details
The function takes a management_df
as input and returns soil cover
days per year in the management_df.
Alternatively, it can return a soil_cover_tibble
with daily resolution
of the estimated soil cover.
The function calculates plant soil cover with the plant_cover()
function
and the soil coverage by residues.
The residue mass is dependent on the residue supply by crops, its decay and its incorporation by tillage operations (Büchi et al. 2016).
Residue supply is estimated with the yield dependent
residue C C_input_straw
provided by the function C_input_crops()
and
a C content of 450 \ [mgC/gDM]
.
If residues are removed, the removed residue mass is subtracted.
Residue decay is calculated with the formula of Steiner et al. (1999):
M_t = M_{t-1} * (1 - k_{decay})
Where M_{t-1}
is the residue mass of the prior day [g/m^2]
and
k_{decay}
is the daily decay rate that was assumed to be
0.028
g/g
, the average decomposition rate of winter wheat straw
(Steiner et al. 1999).
Residue incorporation by tillage was estimated with the operation-specific
burial coefficient extracted from the RUSLE2 database
(USDA-NRCS 2023) that are provided in the
look-up-table STIR_values_LUT
.
Residue mass is translated into percentage of soil cover by the formula of Steiner et al. (2000):
cover_{residues} = (1-e^{-k(M)})* 100 \%
Where M
is the residue mass [g/m^2]
and k
is a cover
coefficient [m^2/g]
. k
was assumed to be 0.0175
(Steiner et al. 2000).
Value
By default, a tibble with soil cover days by year is returned.
If extended.output = TRUE, an object of the class
soil_cover_tibble
with daily resolution is returned.
References
Büchi L, Valsangiacomo A, Burel E, Charles R (2016).
“Integrating simulation data from a crop model in the development of an agri-environmental indicator for soil cover in Switzerland.”
European Journal of Agronomy, 76, 149–159.
doi:10.1016/j.eja.2015.11.004.
Steiner JL, Schomberg HH, Unger PW, Cresap J (1999).
“Crop residue decomposition in no-tillage small-grain fields.”
Soil Science Society of America Journal, 63(6), 1817–1824.
doi:10.2136/sssaj1999.6361817x.
Steiner JL, Schomberg HH, Unger PW, Cresap J (2000).
“Biomass and residue cover relationships of fresh and decomposing small grain residue.”
Soil Science Society of America Journal, 64(6), 2109–2114.
doi:10.2136/sssaj2000.6462109x.
USDA-NRCS (2023).
“Revised Universal Soil Loss Equation, Version 2 (RUSLE2), Official NRCS RUSLE2 Program and Database (V 2023-02-24).”
USDA-NCRS.
https://fargo.nserl.purdue.edu/rusle2_dataweb/RUSLE2_Index.htm.
See Also
-
calculate_indicators()
to calculate all management indicators for amanagement_df
-
calculate_soil_cover_tibble()
a helper function that calculates the soil cover tibble -
plant_cover()
for more detail on the plant cover function -
plot.soil_cover_tibble()
for plotting thesoil_cover_tibble
-
STIR_values_LUT
for tillage operation specific burial coefficients
Examples
#example that returns annual soil cover days by plants and residues
soil_cover(EXAMPLE_data)
#example that returns a soil_cover_tibble
soil_cover(EXAMPLE_data, extended.output = TRUE)