Figure 3
From: Forbs enhance productivity of unfertilised grass-clover leys and support low-carbon bioenergy
Annual biomass yield as observed (Obs) and expected (Exp) in the four seed mixtures in 2014 (a,b) and 2015 (c,d) without (a,c) and with (b,d) fertilisation. The expected values are calculated as the weighted mean biomass yield in pure stands in the respective year. Data are means ± SE (n = 3) for each component species. Asterisks refer to significant differences (P < 0.05) between expected and observed yield for each component species.
