Seeking for Ratios and Correlations from Field Data for Improving Biomass Assessments for Agricultural Pruning in Europe. Methods and Results

Biomass assessments of agricultural prunings base usually on average ratios of tons per hectare (t/ha) of biomass, usually known as residue to surface ratio (RSR). In biomass assessments at European scale it is usual the utilization of a single ratio per species for whole Europe. However, when comparing country or regional pruning biomass assessments, ratios are quite varying. EuroPruning project (FP7 contract 312078) has developed a methodology to find out relations between the pruning RSR and several of the mentioned factors. A database has been implemented from 61 surveys and multiple literature references, adding a total of 230 records from 7 countries. More than 20 climatic, agro-climatic and agro-ecological parameters were added to each record. The statistical analysis indicated small correlations for most of the variables, except for few agro-climatic variables. Regression study was applied to vineyards and citrus. Ramp functions were prepared for all crop groups: vineyards and citrus based on the regression model, and olive, nuts and fruits based on a zoning of the scatter plot. The ramps were applied to the agro-climatic GIS coverages to obtain a specific RSR ratio by NUTs3 and NUTs2. The theoretical biomass potential has been obtained by NUTs2 by multiplying each NUTs2 ratio by the NUTs2 crop area. Results were aggregated to obtain the EU28 member states biomass potentials. The final result is a theoretical potential in EU28 of more than 13 Mt of dry matter per year from agricultural prunings.
Proceedings of the 24th European Biomass Conference and Exhibition, 6-9 June 2016, Amsterdam, The Netherlands, pp. 214-232