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 management_df that contains the management information

extended.output

an optional logical value.

  • If FALSE, soil cover days are aggregated by year.

  • If TRUE, a soil_cover_tibble with daily resolution is returned.

  • Default value is FALSE

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

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

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)



[Package SoilManageR version 1.1.0 Index]