Biomass availability and quality produced by vineyard management during a period of 15 years

Agricultural residue could become a potential biomass source for energy production because it is available every year in areas accessible to tractors and vehicles. The aim of this work was to quantify the biomass available and its fuel characteristics, considering pruning residue from management of five main vine varieties planted in northwest Italy (barbera, dolcetto, cortese, cabernet sauvignon, and moscato) for a period of 15 years (from 2000 to 2014). Throughout the test period, pruning residue production ranged between 0.45 and 1.34 kg (1850-5360 kg ha−1) per plant. The average higher heating value of the five vine varieties tested ranged from 17.92 to 18.02 MJ kg−1, whereas the lower calorific value ranged between 7.34 and 7.96 MJ kg−1. The average ash content was approximately 3.85%. No statistical difference in biofuel characteristics was found between the vine varieties considered. This study highlights the high potential of vineyard pruning residue as a biofuel for energy production. In contrast, it is of considerable importance to know that biomass production can vary considerably between vine varieties and between years. This latter aspect is very important because, according to reference years, it is possible to under- or overestimate biomass production.