Seasonal Dynamics of Dry Matter Accumulation and Nutrients in a Mature <i>Miscanthus × giganteus</i> Stand in the Lower Silesia Region of Poland

Abstract

Biomass from M. × giganteus has great promise for use within the bioeconomy sectors, but to maximise environmental benefits, crops must produce high yields while minimising energetically costly inputs. Complex interactions between soil conditions, climatic variations, plant maturity and genotype influence yields and nutrient dynamics, which in turn impacts crop sustainability. To investigate the flux of growth and nutrients in response to a changing environment, M. × giganteus was grown in southwest Poland and sampled monthly (June–November) from 2010 to 2012. Measurements examined the interaction between plant growth and leaf development, and nutrient (N, P, K, Ca and Mg) concentrations of rhizomes, stems and leaves. The three growth years studied were markedly different for growth and meteorological conditions. Between 2010 and 2011, above ground biomass yield increased significantly from 16.5 ± 0.4 t ha−1 to 20.1 ± 0.5 t ha−1. The 2012 rhizome weights at the beginning of the growth season were halved due to extreme frost; however, resulting yield was similar (19.9 ± 0.6 5 t ha−1). Final yield from all three years were successfully predicted using MISCANFOR, and modelling indicated crop yield was water-limited. The seasonal flux of N and K from rhizome to stems and leaves then back to the rhizome at the onset of senescence was as expected in 2010 and 2011. In 2012, no such trend was evident especially for N suggesting different macronutrient sources from rhizome and soil improves the resilience of perennial crop yield across a range of diverse growth conditions.

Keywords

• miscanthus
• bioenergy
• nutrients
• senescence
• nutrient remobilisation
• yield resilience