R/NRE.R

In NUETON: Nitrogen Use Efficiency Toolkit on Numerics

#' Calculate Fertilizer-N Recovery Efficiency
#' @description
#' The percentage of fertilizer N that is taken up by the plant,
#' accounting for background soil N levels; also sometimes referred to as apparent recovery.
#' Calculate NRE using the formula: NRE = ((PlantNf - PlantN0) / FertN) * 100
#' @param PlantNf A numeric vector of values for plant N at the end of the experiment.
#' @param PlantN0 A numeric vector of values for plant N at the beginning of the experiment.
#' @param FertN A numeric value for fertilizer N input.
#' @returns The calculated NRE value as a percentage.
#' @examples
#' PlantNf <- c(2.92, 3.78, 4.68, 4.21)
#' PlantN0 <- c(1.22, 2.66, 3.99, 2.58)
#' FertN <- 15
#' NRE(PlantNf, PlantN0, FertN)
#' @references
#' Primary: Congreves, K. A., Otchere, O., Ferland, D., Farzadfar, S., Williams, S., & Arcand, M. M. (2021, June 4).
#' Nitrogen Use Efficiency Definitions of Today and Tomorrow. Frontiers in Plant Science, 12.
#' https://doi.org/10.3389/fpls.2021.637108
#'
#' Secondary: Dobermann, A. (2007). “Nutrient use efficiency–measurement and management,”
#' in Proceedings of the International Fertilizer Industry Association (IFA) Workshop on Fertilizer Best Management Practices, 7–9 March 2007, Brussels, 1–28.
#' @export


NRE <- function(PlantNf, PlantN0, FertN) {
  if (length(PlantNf) == 0 || length(PlantN0) == 0 || FertN == 0) {
    stop("Inputs should not be empty, and FertN should not be zero.")
  }
  if (any(PlantNf < PlantN0)) {
    stop("PlantNf should be greater than or equal to PlantN0.")
  }
  NRE <- ((mean(PlantNf) - mean(PlantN0)) / FertN) * 100
  return(NRE)
}