SOME ASPECTS OF THE DEVELOPMENT OF SHORT-ROTATION COPPICE WILLOW FOR BIOMASS IN NORTHERN-IRELAND

Work on short-rotation coppice willow as an alterative and renewable energy source began in Northern Ireland in the mid-1970s, prompted by the massive rise in oil prices during that period. Although in the short run oil prices have dropped in real terms, interest in short-rotation coppice willow has ben sustained because of the potential role it has in the development of agriculture, particularly in marginal areas. This is particularly relevant in the current situation of over production of a wide range of agricultural commodities within the European Community and the moves to reduce Government support in the form of farm and export subsidies. Although Salix cultivars have yielded in excess of 30 tonnes dry matter (DM) ha-1 annually under experimental conditions, it is considered that 10-12 tonnes DM ha-1 is a sustainable commercial yield. Melampsora spp. rust has emerged as one of the most important factors limiting the development of short-rotation coppice as a commercial crop. For economic and environmental reasons, the application of fungicide for rust control is not a possibility. Consequently, other disease control strategies have to be established. The main focus of this work is in the selection, for suitability for coppice application, of the widening range of genetic material becoming available from breeding programmes in Canada, Sweden and Finland with a view to their incorporation into mixed stands. End product utilisation is considered a priority area for investigation if short-rotation coppice is to make a contribution to land use and the development of agriculture in marginal areas. Currently two potential end uses are being investigated: firstly fractionation - to produce cellulose for paper manufacture, hemi-cellulose for the production of molasses and lignin for further processing into other industrial chemicals, and secondly the simultaneous generation of heat and power using gasification - 'combined heat and power'.