Effects of several establishment modes of Miscanthus × giganteus and Miscanthus sinensis on yields and yield trends

Abstract

Miscanthus is a C4 perennial grass originating from East Asia, the yields of which progressively increase in the first years of growth. Several species for bioenergy have been studied since the mid‐1980s in Europe, in particular (Miscanthus × giganteus [M. × giganteus]), due to its high yields. M. × giganteus is mainly cultivated in France and established from rhizomes. Our study aimed to assess, in field conditions, alternative establishment methods combined with an alternative species, Miscanthus sinensis (M. sinensis). We set up a multi‐environment experimental network. On each trial, we tested two treatments with M. × giganteus, established from rhizomes (G_r‐sd) and from plantlets obtained from rhizomes (G_p‐sd), and two treatments with M. sinensis seedlings transplanted in single (S_p‐sd) and double density (S_p‐dd). ANOVA was performed to compare establishment and regrowth rates across treatments, as well as yields across treatments and site‐years. A logistic model was used to describe yield trends and to compare the maximum yield reached and the rate of yield increase of both species. Results showed that miscanthus establishment from plantlets resulted in higher establishment (between 87% and 92%) and regrowth (between 91% and 94%) rates compared to establishment from rhizomes. Treatments with M. × giganteus obtained higher average yields across site‐years than those with M. sinensis, but more variable yields across site‐years. We showed a strong species effect on yields, yield components (shoot weight, shoot density and shoot number per plant) and light interception (through leaf area index). Lastly, to use M. sinensis established from transplanted plantlets as an alternative to M. × giganteus, research would be required on the breeding of M. sinensis sterile seeds to avoid risks of invasiveness.

Evolution of soil carbon stocks under Miscanthus × giganteus and Miscanthus sinensis across contrasting environmental conditions

“…(2015) showed that after 14 years of cultivation, the quantity of mulch (crop residues present on the soil surface, originating from fallen leaves and harvest losses) was similar under M. × giganteus (9.3 t/ha of DM) and M. sinensis (8.9 t/ha of DM). Furthermore, the leaf area index was also similar for both genotypes in our trial network, despite lower yields for M. sinensis than for M. × giganteus (Ouattara et al., 2020). We can therefore assume that the aboveground C inputs were similar between the two genotypes.…”

Identifying Factors Explaining Yield Variability of Miscanthus x giganteus and Miscanthus sinensis Across Contrasting Environments: Use of an Agronomic Diagnosis Approach

“…During the juvenile phase of miscanthus cultivation, yields increase before reaching a plateau [5,10,31,32]. The effect of crop age on yield is more pronounced for M. x giganteus than M. sinensis because of its longer juvenile period [5]. Moreover, the higher the previous year's yields, the higher the current year's yields, at least for the juvenile phase.…”

“…x giganteus and M. sinensis. During the juvenile phase of miscanthus cultivation, yields increase before reaching a plateau [5,10,31,32]. The effect of crop age on yield is more pronounced for M. x giganteus than M. sinensis because of its longer juvenile period [5].…”

“…2). before transplanting [5]. To summarize, 4 treatments of M. x giganteus and M. sinensis were carried out under 7 sites × 5 years of harvest.…”

“…where Y is the yield (t.ha −1 of DM), FM is the fresh matter of the sub-plot (kg), FW is the fresh weight of the sub-sample (kg), DW is the dry weight of the sub-sample (kg), and A is the sub-plot area (m 2 ). These measurements were fully described in [5].…”