Site impacts nutrient translocation efficiency in intraspecies and interspecies miscanthus hybrids on marginal lands

Abstract

Miscanthus, a C4 perennial rhizomatous grass, is capable of growing in varied climates and soil types in Europe, including on marginal lands. It can produce high yields with low nutrient inputs when harvested after complete senescence. Senescence induction and rate depend on complex genetic, environmental, and management interactions. To explore these interactions, we analysed four miscanthus hybrids (two novel seed‐based hybrids, GRC 3 [Miscanthus sinensis × sinensis] and GRC 14 [M. sacchariflorus × sinensis]; GRC 15, a novel M. sacchariflorus × sinensis clone; and GRC 9, a standard Miscanthus × giganteus clone) in Italy, Croatia, Germany and the UK. Over all trial locations and hybrids, the average aboveground biomass of the 3‐year‐old stands in August 2020 was 15 t DM ha−1 with nutrient contents of 7.6 mg N g−1 and 14.6 mg K g−1. As expected, delaying the harvest until spring reduced overall yield and nutrient contents (12 t DM ha−1, 3.3 mg N g−1, and 5.5 mg K g−1). At lower latitudes, the late‐ripening M. sacchariflorus × sinensis GRC 14 and GRC 15 combined high yields with low nutrient contents. At the most elevated latitude location (UK), the early‐ripening M. sinensis × sinensis combined high biomass yields with low nutrient offtakes. The clonal Miscanthus × giganteus with intermediate flowering and senescence attained similar low nutrient contents by spring harvest at all four locations. Seasonal changes in yield and nutrient levels analysed in this study provide: (1) a first step towards recommending hybrids for specific locations and end uses in Europe; (2) crucial data for determination of harvest time and practical steps in the valorization of biomass; and (3) key sustainability data for life cycle assessments. Identification of trade‐offs resulting from genetic × environment × management interactions is critical for increasing sustainable biomass supply from miscanthus grown on marginal lands.

Yield performance of 14 novel inter‐ and intra‐species Miscanthus hybrids across Europe

“…For climates with mild wet winters where the more productive sac × sin hybrids are grown harvest methods are being developed to reduce the moisture before the crop is transported from the field, such as the common technique in wetter climates of cutting to a swath (Hastings et al, 2017; Lewandowski et al, 2000). This moisture content is very affected by leaf to stem ratio at harvest, with leaf contributing more moisture (Magenau, Clifton‐Brown, Awty‐Carroll, et al, 2022).…”

Spring emergence and canopy development strategies in miscanthus hybrids in Mediterranean, continental and maritime European climates

“…We found that M sin × sin (GRC 3) has a more effective strategy for avoiding damage from late spring frosts: firstly, later emergence and secondly, higher frost tolerance. This could help explain why M sin × sin achieves higher yields than M × g and M sac×sin at colder locations (Awty‐Carroll et al, 2022; Magenau et al, 2022).…”

Valorisation of marginal agricultural land in the bioeconomy

“…The end-of-season ripening behaviour of miscanthus is a main driver for maintaining a high harvestable yield quantity, while achieving biomass quality requirements and minimizing nutrient offtakes by the harvested biomass. Magenau et al (2022) studied the dynamics of the senescence processes of different miscanthus hybrids. Generally, it was found that delaying the harvest until spring reduced overall yield, moisture and nutrient contents for all novel hybrids tested.…”

“…Magenau et al. (2022) studied the dynamics of the senescence processes of different miscanthus hybrids. Generally, it was found that delaying the harvest until spring reduced overall yield, moisture and nutrient contents for all novel hybrids tested.…”