SoilManageR (version 1.0.1)

C_input_cover_crops: Estimate C inputs by cover crops

Description

This function estimates the Carbon (C) input into the soil system by cover crops based on the duration of the cover crop stand.

Usage

C_input_cover_crops(
  abvg_biomass = NA,
  days = 180,
  min_C_abvg = 1253,
  min_days = 180,
  max_C_abvg = 1916,
  max_days = 240,
  Cc_biomass = 450
)

Value

a tibble with the following parameters:

• C_input_product: Estimated soil carbon input from product (i.e., the cover corp aboveground biomass) (kgC/ha),

• C_input_straw: Estimated soil carbon input by straw or other residues (typically 0 for cover crops) (kgC/ha),

• C_input_root: Estimated soil carbon input by roots (kgC/ha),

• C_input_exudate: Estimated soil carbon input by roots (kgC/ha),

• C_input_total: Total estimated Soil carbon input, sum of C_input_straw, C_input_root, C_input_exudate (kgC/ha),

Arguments

abvg_biomass

(optional): Dry weight of aboveground biomass of the cover crop (tDM/ha)

days

(optional): Number of days that the cover crop was established. If no value is provided, mind_days is assumed (days)

min_C_abvg

(optional): Minimal above ground C that the cover crop produces, given it is established for the min_days number of days. Default value is 1.253 (kgC/ha)

min_days

(optional): Number of days where the interpolation of the biomass starts. The default value is 180 (days)

max_C_abvg

(optional): Maximum biomass that the cover crop can produce. Default value is 1.916 (kgC/ha)

max_days

(optional): Number of days when the maximum biomass of the cover crop is reached. The default value is 240 (days)

Cc_biomass

(optional): Assumed C content of the cover crop biomass. Default value is 450 (kgC/tDM)

Details

C_input_cover_crops() internally calls C_input_crops() to calculate the different C fractions. The C in the above ground biomass (\(C_{Product}\)) is a function of the time a cover crop is established. A minimum and a maximum cover crop biomass are assumed at 180 and 240 days respectively, and linearly interpolated for the period in between. $$C_{Product} = \begin{cases} 1253\ kgC/ha \ , \ duration < 180 \ days \\ 1253 \ kgC/ha \ + \ (duration - 180 \ days) \ * \frac{663 \ kgC/ha}{60 \ days} \ , \ 180 \ days \leq duration \leq 240 \ days \\ 1916 \ kgC/ha \ , \ duration > 240 \ days \end{cases}$$

Assumptions on the C inputs at day 180 and 240 are based on values extracted from seitz2022;textualSoilManageR.

The remaining parameters to calculate the C input by cover crops are HI = 1, SER = 3.67, and REF = 0.31, all derived from seitz2022;textualSoilManageR.

Note, that with these assumptions the C input of short term cover crops (e.g. few weeks) is overestimated.

The function C_input_cover_crops() estimates the C input by applying the assumptions mentioned above. Alternatively, the user can supply an above ground biomass and a CC of the biomass, or other parameters to estimate the C input by cover crops.

References

See Also

• C_input() to calculate C inputs for a management_df

• C_input_crops() to calculate C input for crops

• CN_input_amendments() to calculate C (and N) inputs for organic amendments

• C_input_crops_LUT() for the look-up-table for crop reference values

Examples

#example when only the duration is known
C_input_cover_crops(days = 205) 

#example if the cover crop biomass is known
C_input_cover_crops(abvg_biomass = 2.5, Cc_biomass = 450) 

#example with custom assumptions on the above ground biomass developnent over time
C_input_cover_crops(days = 60, min_C_abvg = 600 , min_days = 50, max_C_abvg = 1916, max_days = 240)