Data from: Biomass yield, yield components and growing season phenotypic measurements of Miscanthus

For sustainable biomass production of Miscanthus × giganteus (hereafter
miscanthus), understanding the impact of stand age and nitrogen (N)
fertilization on biomass yield is crucial. This study investigated the
effects of varying N fertilization rates (0, 56, 112, and 168 kg N ha-1)
on yield components (tiller height, density, and weight) and their
correlations with end-of-season biomass yield in miscanthus. We also
explored end-of-season biomass yield prediction using in-season traits
(canopy height, leaf area index (LAI), and leaf chlorophyll content
(LCC)). The study was conducted at two sites in Illinois: a previously
unfertilized 10-year-old miscanthus research stand at Urbana and a
16-year-old commercial stand at Pesotum with a history of annual 56N
application. Results from 2018-2021 in Urbana and 2020-2021 in Pesotum
showed increased biomass yields with N fertilization, varying by rate,
year, and location. Biomass yield in Pesotum peaked at 56N, while in
Urbana, it increased significantly at 112 kg N ha-1. Biomass yield was
strongly correlated with tiller height and weight measured at Urbana
across N rates. Morphological traits measured every 2-3 weeks during the
2020 and 2021 growing seasons showed that canopy height was the strongest
single predictor of miscanthus biomass yield, followed by LCC. Mid-August
to September measurements of these traits were the best predictors of
biomass yield. Multiple regressions involving the canopy height and LCC
further improved yield predictions. We conclude that while N enhances
biomass yields of aging miscanthus, the optimum rate depends on the site,
environmental conditions, and management.