Responses in chemical traits and biomass allocation of Arundo donax L. to deficit resources in the establishment year

摘要

A large expansion in renewable energy production is underway with an increasing focus on sustainable second-generation\udbiofuels. Fast growing rhizomatous perennial grasses are leading candidates for lignocellulosic feedstock thanks to their\udpositive energy balance, and low ecological/agro-management demands. Biomass accumulation is favored by the efficient\uduse of available resources. The aim of this study was to identify which accumulation processes were most affected in the\udestablishment year of a giant reed (Arundo donax L.) field crop grown under water and N deficiencies. The relative plasticity\udof growth of A. donax in response to various levels of resource availability was evaluated. A field scale experiment was\udcarried out, and treatments were arranged as a randomized complete block, strip-plot design with irrigation treatments as\udthe main plot factor and pre-planting N rate as the sub-plot factor. Biometric relationships between variables were assessed\udto understand how agro-management factors influence the above ground biomass of giant reed, as well as yield over\udtime. Evidence is presented indicating that growth is strongly enhanced by water availability (+97% dry weight biomass).\udChanges in composition were not significant within or among fixed treatments, rather changes were observed over time.\udA high content of glucans and xylans were detected from early stage, and as the mobilization of minerals increased, lignin\udcontent significantly increased as well (from 12% to 36% w/w). These results suggest that an increase in the growth of A.\uddonax in the establishment year is accomplished by a limited use of the water input.