Quantification of the residual biomass obtained from pruning of trees in Mediterranean almond groves

This research quantified the available residual biomass obtained from pruning almond trees. The additional biomass quantified could be used as a source of energy or as raw material for the wood industry and would provide additional income for fruit producers and also a more sustainable system. Several factors were analyzed: Variety, aim of the pruning, age of the plants, size of the plantation, crop yield and irrigation. Regression models were also calculated to predict the weight of dry biomass obtained per tree and tonnes of dry biomass obtained per hectare according to the significant factors. These equations could implement logistic planning as the Borvemar model, which defines a logistics network for supplying bioenergy systems. Almond tree varieties were classified into three groups: a first group with high residual biomass productivity (average yield 12.6 kg dry biomass/tree), a second group with low productivity (average yield 4.5 kg dry biomass/tree) and a transition group with a intermediate biomass yield of 7 kg dry biomass/tree. This means that in Mediterranean areas the residual biomass from almond pruning reaches an average 1.34 t/ha annual.