nutribal: Compute the Nutrient Balance of a Management Scenario
In BenjaminDelory/heathland: Analysis of Heathland Management Trade-offs

Description Usage Arguments Details Value Author(s) See Also Examples

This function computes the balance of one essential nutrient for one management scenario.

nutribal(x, data=import_nutrients(), sqa=list(grazing=1, mowing=5, burning=5, choppering=7),
        bioleft=list(mowing=5133.63, burning=1888.96), nutrient="N", Datm=NULL,
        gompertz=list(a=20148.38, b=8.48362, c=6.647557), sheep.pressure=0.5, 
        plot.biomass=FALSE, cumulative=TRUE, ...)

`x`	A management scenario (see details).
`data`	A `nutrients` object created by `import_nutrients`.
`sqa`	A list giving the time period until leaching rates reach status quo ante (years) for each management.
`bioleft`	A list giving the standing plant biomass (in kg/ha) left after mowing and burning.
`nutrient`	The nutrient to focus on. Could be either `“N”`, `“P”`, `“K”`, `“Mg”`, or `“Ca”`.
`Datm`	The atmospheric deposition for the target nutrient (in kg/ha/year).
`gompertz`	The parameters of the Gompertz model simulating plant biomass production over time.
`sheep.pressure`	Numeric value comprised between 0 and 1. A sheep pressure of 0 means that no sheep is present. A sheep pressure of 1 means that the sheep density equals 1.1 sheep/ha when a grazing management occurs.
`plot.biomass`	Logical value. Should the evolution of the standing plant biomass be plotted? TRUE is yes, FALSE is no.
`cumulative`	A logical value. Should the cumulative nutrient balance be calculated? TRUE is yes, FALSE is no.

A management scenario should be given as a numeric vector. The following convention is used: 0 for no management, 1 for grazing, 2 for mowing, 3 for burning, and 4 for choppering. The vector should have a length equal to the number of simulated years (1 management per year) and must start with choppering.

Returns a numeric vector reporting the (cumulative) nutrient balance (kg/ha).

Benjamin M. Delory

import_nutrients.

#Compute the N balance
balance<-nutribal(c(4,0,0,0,0,0,0,0,3,0,0))
plot(c(0:10), balance, type="l", lwd=2, ylab="Cumulative N balance (kg/ha)",
xlab="Time (years)", bty="l", las=1, col="red")
abline(h=0, lty=2)