Main patterns
- S1 (rainfed) exhibits the lowest yield, confirming the strong impact of water deficit.
- S6 improves yield with moderate water inputs but does not reach the production plateau.
- S3, S4, and S9 cluster around similar total water volumes (~540–550 mm) and yields (~12–13 t·ha⁻¹), illustrating that different strategies can converge toward similar outcomes.
- S8 consumes comparable water but delivers lower yield, highlighting the potential cost of restrictive operational rules when they prevent timely protection during peak demand.
- S5 achieves high yield with moderate total water, representing a strong yield–water compromise (high marginal productivity of additional water within this set of strategies).
- S10 reaches the highest yield, but also among the highest total water inputs.
- S7, despite very high water availability, shows limited advantage compared to S10, illustrating diminishing marginal returns at high water supply.
library(ggplot2)
df <- do.call(rbind, lapply(names(outputs), function(nm) {
d <- outputs[[nm]]
data.frame(
Scenario = nm,
Water_mm = sum(pmax(0, d$P), na.rm = TRUE) + sum(pmax(0, d$I1), na.rm = TRUE),
Y = tail(na.omit(d$Y), 1)
)
}))
ggplot(df, aes(x = Water_mm, y = Y)) +
geom_point(size = 3, color = optirrig_view_palette[1], alpha = 0.85) +
geom_text(aes(label = Scenario), hjust = -0.15, vjust = 0.4, size = 3.5) +
scale_x_continuous(
limits = range(df$Water_mm, na.rm = TRUE),
expand = expansion(mult = c(0.02, 0.05))
) +
labs(
x = "Total seasonal water (mm) = ΣP + ΣI",
y = "Yield (t/ha)",
title = "Yield response to total seasonal water"
) +
theme_optirrig_view(base_size = 13)
This plot is useful to distinguish water amount effects from timing / rule effects, since strategies with similar ΣP + ΣI can still achieve different yields.
