R/calcEmisNitrogenNonaglandPast.R

In pik-piam/mrcommons: MadRat commons Input Data Library

#' @title calcEmisNitrogenNonaglandPast
#' @description
#' Calculates nitrogenous emissions from non-agricultural land for the historical period
#' @param method Method for calculating Atmospheric deposition: Nsurplus2 and Nsurplus
#' are based on deposition rates based on own emission calculations after 2 or after 1 iteration, respectively.
#' @return List of magpie object with results on country level, weight on country level, unit and description.
#' @author Benjamin Leon Bodirsky
#' @seealso
#' [calcEmisNitrogenPast()],
#' [calcExcretion()]
#' @examples
#' \dontrun{
#' calcOutput("EmisNitrogenPasturePast")
#' }
#'
calcEmisNitrogenNonaglandPast <- function(method = "Nsurplus") {

  # first iteration: calculate atmospheric deposition based on CEDS and estimate leaching
  # second iteration: calculate deposition based on Nsurplus and Oceans based on leaching
  if (method == "Nsurplus2") {
    budget <- calcOutput("NitrogenBudgetNonagland", aggregate = FALSE, deposition = "Nsurplus")
    method <- "Nsurplus"
  } else {
    budget <- calcOutput("NitrogenBudgetNonagland", aggregate = FALSE, deposition = "CEDS")
  }


  # apply preagshare on nonagland

  preag <- calcOutput("EmisNitrogenPreagriculture", aggregate = FALSE, cellular = FALSE)
  preag <- preag[, , c("crop", "past"), invert = TRUE]
  preagshr <- preag / dimSums(preag, dim = 3.1)

  out <- budget[, , "surplus"] * preagshr
  out <- dimSums(out, dim = c(3.1, 3.2))
  out <- add_dimension(out, dim = 3.1, nm = "nonag_soils")

  return(list(
    x = out,
    weight = NULL,
    unit = "Mt Nr in various forms",
    description = "Nitrogen emissions from non-agricultural land for the historical period"))
}