Multi-year and Multi-site Establishment of the Perennial Biomass Crop Miscanthus × giganteus Using a Staggered Start Design to Elucidate N Response

摘要: Much field research on perennial bioenergy crops confounds effects of plant age with those the growing season, which increases uncertainty and potential for erroneous conclusions, particularly in maturing stands. Most studies rely stands planted a single year measured across multiple subsequent seasons. These “single-start” designs lack statistical power to separate temporal from environment effects. We used staggered start experimental design learn if increased clarified understanding Miscanthus × giganteus nitrogen (N) needs. conducted experiment three planting years five N rates during M. yield-building phase at sites IA, USA. Third-year yields were 21.0, 25.0, 27.1 Mg dry matter (DM) ha−1 northwest (NW), central, southeast (SE) sites, respectively. Nitrogen fertilization changed establishment conditions, but not age. At most responsive site, fertilizer all stand ages, every year. Yield 150%, 36%, 40% observed 1-, 2-, 3-year-old stands, respectively, addition. 1-year-old positive SE IA (2.7 kg DM kg−1 added), negative (− 2.3 kg DM kg−1 N) NW variable central (− 2.2–9.6 kg DM kg−1 N), suggesting site–year-specific response. between first second varied by > 100% depending highlighting need repeated before determining economic agronomic crop viability.