The modelled productivity of Miscanthus x giganteus (GREEF et DEU) in Ireland

The contribution of Miscanthus biomass to an energy or fibre industry in Ir eland can only be estimated if the potential productivity is predicted on a regional basis. In order to parameterise a model to predict dry matter pro duction, growth and climatic measurements were carried out in 1994 and 1995 on a Miscanthus held trial, planted in 1990 in southern central Ireland. T hese were used to derive relationships between: (i) leaf canopy light inter ception and thermal time calculated from air temperatures; and (ii) radiati on intercepted and above ground biomass. These relationships were used to p arameterise an empirical productivity model in which water and nutrient sup plies are assumed non-limiting. The output from this model was incorporated into a geographical information system (GIS) to map the predicted potentia l production of M. x giganteus throughout Ireland, using 10 year daily air temperatures and incident radiation from 23 climatic stations. Across the i sland, potential biomass yields at the end of the growing season, ranged be tween 16 and 26 t DM ha(-1). The model approach and its predictions are dis cussed. (C) 2000 Elsevier Science B.V. All rights reserved.