Calculate application rates for active ingredients

An application rate in g active substance/ha is calculated from information on dosage (product concentration in the application solution) and application volume, or directly from the product application rate. This is complicated by the fact that a rate ("expenditure" in the XML file) with units l/ha can refer to the application solution or to the liquid product.

Usage

application_rate_g_per_ha(
  product_uses,
  aggregation = c("max", "mean", "min"),
  skip_l_per_ha_without_g_per_L = TRUE,
  fix_l_per_ha = TRUE
)

Arguments

product_uses

A tibble containing the columns 'pNbr', 'use_nr', 'application_area_de', 'min_dosage', 'max_dosage', 'min_rate', 'max_rate', from the 'uses' table in a srppp_dm object, as well as the columns 'percent' and 'g_per_L' from the 'ingredients' table in a srppp_dm object and 'culture_de' from the 'cultures' table in srppp_dm object.

aggregation

How to represent a range if present, e.g. "max" (default) or "mean".

skip_l_per_ha_without_g_per_L

Per default, uses where the use rate has units of l/ha are skipped, if there is not product concentration in g/L. This was also done in the 2023 indicator project.

fix_l_per_ha

During the review of the 2023 indicator project calculations, a number of cases were identified where the unit l/ha specifies a water volume, and not a product volume. If TRUE (default), these cases are corrected, if FALSE, these cases are discarded.

Value

A tibble containing one additional column 'rate_g_per_ha'

Details

In some cases (currently one), external information was found, indicating that the "expenditure" is an application volume l_per_ha_is_water_volume.

Note

A reference application volume is used if there is no 'expenditure'. It is selected only based on the product application area and culture.

Examples

# \donttest{
library(srppp)
library(dplyr, warn.conflicts = FALSE)
library(dm, warn.conflicts = FALSE)

sr <- try(srppp_dm())

# Fall back to internal test data if downloading or reading fails
if (inherits(sr, "try-error")) {
  sr <- system.file("testdata/Daten_Pflanzenschutzmittelverzeichnis_2024-12-16.zip",
      package = "srppp") |>
    srppp_xml_get_from_path(from = "2024-12-16") |>
    srppp_dm()
}

product_uses_with_ingredients <- sr$substances |>
  filter(substance_de %in% c("Halauxifen-methyl", "Kupfer (als Kalkpr\u00E4parat)")) |>
  left_join(sr$ingredients, by = "pk") |>
  left_join(sr$uses, by = "pNbr") |>
  left_join(sr$products, by = "pNbr") |>
  left_join(sr$cultures, by = c("pNbr", "use_nr"),
            relationship = "many-to-many") |>
  select(pNbr, name, use_nr,
    min_dosage, max_dosage, min_rate, max_rate, units_de,
    application_area_de, culture_de,
    substance_de, percent, g_per_L)

application_rate_g_per_ha(product_uses_with_ingredients) |>
  filter(name %in% c("Cerelex", "Pixxaro EC", "Bordeaux S")) |>
  select(ai = substance_de, app_area = application_area_de,
    min_d = min_dosage,  max_d = max_dosage,
    min_r = min_rate, max_r = max_rate,
    units_de, rate = rate_g_per_ha) |>
  print(n = Inf)
#> # A tibble: 16 × 8
#>    ai                app_area min_d max_d min_r max_r units_de  rate
#>    <chr>             <chr>    <dbl> <dbl> <dbl> <dbl> <chr>    <dbl>
#>  1 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#>  2 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#>  3 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#>  4 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#>  5 Halauxifen-methyl Feldbau     NA    NA  0.75    NA l/ha      4.69
#>  6 Halauxifen-methyl Feldbau     NA    NA  0.75    NA l/ha      4.69
#>  7 Halauxifen-methyl Feldbau     NA    NA  0.75    NA l/ha      4.69
#>  8 Halauxifen-methyl Feldbau     NA    NA  0.75    NA l/ha      4.69
#>  9 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#> 10 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#> 11 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#> 12 Halauxifen-methyl Feldbau     NA    NA  1       NA l/ha      6.25
#> 13 Halauxifen-methyl Feldbau     NA    NA  0.5     NA l/ha      6.25
#> 14 Halauxifen-methyl Feldbau     NA    NA  0.5     NA l/ha      6.25
#> 15 Halauxifen-methyl Feldbau     NA    NA  0.5     NA l/ha      6.25
#> 16 Halauxifen-methyl Feldbau     NA    NA  0.5     NA l/ha      6.25
# }