Estimate crop above-ground residue biomass.

Estimates crop residue dry matter from production and area using an ensemble of an IPCC 2019 linear model and a bio_coefs residue:product ratio. The irrigation and modern-variety adjustments activate only when their driver columns are present in x.

Usage

calculate_crop_residues(
  x,
  method = c("ensemble", "ipcc", "ratio"),
  weights = list(w_ipcc = 0.5)
)

Arguments

x

A tibble with item_prod_code, production_t (fresh matter) and area_ha. Optional water_regime enables the irrigation adjustment; optional year plus region_hanpp enable the modern-variety adjustment.

method

Residue method: "ensemble" (default, weighted IPCC + ratio), "ipcc" (IPCC linear only) or "ratio" (bio_coefs ratio only).

weights

Named list; w_ipcc is the IPCC weight in the ensemble (0-1, default 0.5), used only when method = "ensemble".

Value

The input tibble with product_dm_t, yield_dm_t_ha, residue_dm_t, method_residue and method_residue_group. The latter is "ipcc_group" for an item with an IPCC crop group, and "unmapped_uncorrected" for one without: that item gets no irrigation or modern-variety residue correction (both are keyed on the crop group), which is not the same as a correction that was computed and found to be 1.

Examples

calculate_crop_residues(
  tibble::tibble(item_prod_code = "15", production_t = 100, area_ha = 40)
)
#> # A tibble: 1 × 8
#>   item_prod_code production_t area_ha product_dm_t yield_dm_t_ha
#>   <chr>                 <dbl>   <dbl>        <dbl>         <dbl>
#> 1 15                      100      40         87.9          2.20
#> # ℹ 3 more variables: method_residue_group <chr>, residue_dm_t <dbl>,
#> #   method_residue <chr>