Fig. 2: Effect of forage crop use (milk, beef or biofuel production) on outputs at contrasting levels of functional richness (FR).

a–d, Model estimates 20 years after implementation for calorie (a), carbohydrate (b), protein (c) and fat (d) outputs. Symbols are model predictions when forage is used to produce milk (filled triangles), beef (open triangles) and biofuel (stars; Table 1 and Extended Data Tables 1 and 2). FR is the number of functional types included in the rotation, with FR 1M referring to a cereal monoculture and FR 1C a cereal-only rotation. The statistical models were obtained by fitting the 12,517 whole-rotation outputs relative to the 16 long-term experiments (Supplementary Table 1). Whiskers extend over the 5–95% confidence intervals. Horizontal dashed lines mark model-predicted outputs for the cereal monoculture (FR 1M) at year 0. Output changes across forage crop use of cereal monocultures and cereal-only rotations are not reported, as they do not include any forage crops (Supplementary Table 1). Significances refer to contrasts between each FR and forage crop use with FR 1M and time 0 as baseline (*P < 0.05; **P < 0.01; ***P < 0.001). Post hoc two-sided tests were adjusted for multiplicity using multivariate t-distribution.