Crop growth analysis and yield of a lignocellulosic biomass crop (Arundo donax L.) in three marginal areas of Campania region

The depletion of energy resources from fossil fuels and global warming have pushed to consider the agro-energy as one of the renewable energy sources for mitigation of climate change. In this context, agro-energy based on cultivation of energy crops in marginal lands allows to reduce competition with food crops and marginal lands abandonment, producing incomes for farmers. The aim of this work is to improve the knowledge on a promising crop (Arundo donax L.) for the production of bio-energy in marginal lands. Therefore, the behavior of this crop was evaluated in three study areas of Campania region, under different energy inputs: two levels of nitrogen fertilization, N100 and N50 in Sant’Angelo dei Lombardi (SA) and Bellizzi (BL). In Acerra (AC) site compost fertilization was made with the aim to verify its effect on pollutant phytoextraction. In the last year, also crop growth analysis was done in the three sites. The results showed that giant reed confirms its adaptability to low fertility soils, allowing interesting biomass yield also in marginal lands. In more fertile environments, effect of fertilization is not significant at least in the short terms. Nevertheless, N uptake (65–130 kg ha– 1), also if lower than other high-yielding crops, needs to be compensated with fertilization for avoiding depletion of soil nutrient reserves, with the aim to guarantee sustainability of this cropping system. Giant reed had a positive environmental impact, due to the improvement in soil fertility (soil organic matter and N increase) and to the mitigation of climate change (C storage in the soil). This crop confirms in marginal soils of Southern Italy, an increasing trend of yield during the first 3-4 years. High productivity levels of this crop are related to the extremely high duration of vegetative period and thus of photosynthetic activity (from March to November in Mediterranean area), well expressed by LAD index that is more than double as compared with other high-yielding crops such as maize (280 vs. 140 days).