Nitrogen dynamics in a mature Miscanthus x giganteus crop fertilized with nitrogen over a five year period
Year: 2014
Type: other
Abstract: The objective of this study was to investigate N dynamics and response to N fertilization\nin a mature crop of Miscanthus x giganteus. A crop of Miscanthus x giganteus sown\nin 1994 was fertilized with five N rates (0, 38, 63, 90 and 125 kg N/ha/year) over a five\nyear period (2008–2012) in Carlow, Ireland. Foliar chlorophyll concentrations were\ndirectly related to N fertilization level throughout the study and rose after N applications\nuntil July before falling with the onset of N remobilisation. Shoot numbers were\nunaffected by N fertilization until the final years of the study when they increased with\nN level. Crop height was unaffected by fertilization in the early years of the study but\nin the final years of the study, it increased with N level until July after which the effect\ndiminished. There was a small but significant stimulation of harvested biomass yields\nin autumn (average 15 t/ha) with increasing N fertilization, but there was no effect\non harvested yields in spring (average 10.5 t/ha). The N concentration in the rhizome\nnetwork gradually built up during the course of the study and was proportional to\nN application. Aboveground biomass N content was also proportional to N application.\nNitrogen remobilisation between the October and February harvests was small;\nabscissed leaves accounted for most of the N loss over this period. The deleterious environmental\nconsequences of N fertilizer may outweigh any potential economic benefits if\nincreases in biomass production are small or non-existent.
Authors: John Finnan, Brendan Burke
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2128806953