Extended Data Fig. 7: The harvest index at the community level in response to plant diversity and country.
From: Diversity increases yield but reduces harvest index in crop mixtures
Harvest index calculated at the community-level as the ratio between plot-level seed yield and plot-level aboveground biomass (that is the sum of aboveground vegetative biomass and seed yield), irrespective of species. Data shown are mean and 95% CI. n = 762 plots. The contrast of diversity vs mixture is marginally significant as a main effect [F(1,44.9) = 3.05, P = 0.088], and significant in interaction with country [F(1,675.1) = 4.96, P = 0.026], while the contrast between 2- and 4-species mixtures is not significant. Statistical tests were done on a linear mixed effects model with type-I analysis of variance and Satterthwaite approximation.
