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Giant reed (Arundo Donax L.) is a perennial, non-food and low-input energy crop representing a promising solution to produce renewable energy at low cost, especially in marginal areas - i.e. low profitable areas which are prone to land abandonment. This research investigates the effect of two levels of irrigation (100% ETm and rainfed) on a 20-year old plantation of 40 genotypes of giant reed (Arundo donax L.) collected around Southern Italy. The experimental methanogenic potential of the biomass was defined trough the BMP test (Biochemical Methane Potential). The trial shows that several genotypes maintain high biomass yield and thus high biomethane potential yield even from old plantations. The variability of biomass yield and biomethane potential yield among genotypes is high. Giant reed genotypes show a positive response to the irrigation, which represent the main limiting factor in Mediterranean environments. Proceedings of the 28th European Biomass Conference and Exhibition, 6-9 July 2020, Virtual, pp. 234-237

Coconut coir dust is finding broad application in the ornamental sector as peat substitute. However, deeper investigations are needed since its performances are variable and not always optimal for different plant species and growing conditions. The use of non-thermal plasma (NTP) in re-circulating nutrient solution appears a promising and sustainable strategy to enhance crop protection, decrease the use of sanitizers and pesticides, and increase yield and quality of ornamental productions. Nevertheless, only a few examples of NTP application on containerized crops under operational growing conditions are available, particularly in combination with different substrates and fertigation regimes. In this work the application of NTP was tested on the nutrient solution used for the production of Ranunculus asiaticus potted plants. The effect was assessed in growing plants using two substrates (both 50:50 v v-1): 1) peat:perlite, and 2) coconut coir dust:perlite, and with two levels of fertilization. Plants grown on coconut coir dust had lower total biomass and flower number. On the other hand, in terms of biomass and tissue nutrient content, R. asiaticus plants developeded better at lower nutrient concentration than at the standard nutrient solution. NTP treatment increased the green biomass while did not improve the flower production. NTP-based sanitizing effects on the root zone, where the number of colony-forming units of fungi was significantly reduced, were observed only in presence of the standard nutrient solution.

Viticulture is a worldwide agricultural sector with a relevant economic importance, especially in regions where the climate and environmental conditions meet requirements for the production of high quality wines. The impact of climate change combined with the increased frequency of extreme events predicted for the next future has already shown its potential detrimental effects on viticulture suitability, but few studies currently explored the effect of long-term climate change and extreme events by considering the inter-varietal variability of grapevine. In this study, the combined effect of mean climate change and extreme events (frost events at bud break and suboptimal temperatures for fruit-set) under future scenarios (RCP 4.5 and 8.5 for two time slices 2036-2065 and 2066-2095, respectively) was evaluated considering four grapevine varieties with very early, early, middle-early and late phenological cycles. The UniChill model calibrated for these varieties was applied in Europe to assess phenological dynamics (budbreak and flowering) using the outputs of a statistical downscaling procedure. Frost impact around budbreak stage as well as the impact of suboptimal temperature around flowering was estimated under present and future scenarios. The results showed a general earlier occurrence of budbreak and flowering stages with a particular relevance on northeastern Europe. The effect of warmer temperatures had a greater effect on late compared to very early and early varieties in western regions. The frequency of frost events at budbreak (T-min < 0 degrees C) showed wide variability across Europe, with a strong decrease in western regions (e.g. Spain and UK) and an increase in central Europe (e.g. Germany) for future scenarios. The decrease in the frequency of frost events was especially evident for very early and early varieties. The impact of suboptimal temperatures at flowering evidenced a significant variability across a latitudinal gradient while this effect did not show significant results when comparing cultivars and scenarios. The results of these studies highlighted that in a warmer climate frost events rather than stress at flowering will reshape the distribution of grapevine varieties in Europe.

The three different future scenarios showed an increase in mean temperature for all months between 0.5-2.4°C and a reduction in precipitation (by 4-7%) for the period 2030-2059 (MPI, KNMI, SMHI). The results of the present work show that climate change will bring a reduction of water resource availability and some alterations in the hydrological regime. The SWAT model, which proved to be a valuable operational tool for evaluating the potential impact of climate change on water resources, estimates a reduction of total water yield and a shift of the flow regime towards drier conditions, although the river type classification will probably remain essentially unvaried. A sever reduction of snowfall in the mountainous part of the basin was also estimated that is expected to impact the flow regime. However, it is important to take into account that several sources of uncertainties, which depend both on the used hydrological models and on the climate change scenarios, affect the predictions of the hydrological response of a river basin under climate change. In addition, some of the assumptions made (i.e. that land use does not change in the future) could be incorrect as climate change could also result in a significant alteration of land cover. Hence, we have to consider projections not as a predictive method, but as a tool that may be used to assess changes in process dynamics.

The current advancement of the bioenergy sector along with the need for sustainable agricultural systems call for context-specific crop residue management options - implying variable degrees of removal - across climatic regions, soil types and farming systems around the world. A large database (n=660) on the effects of crop residue management on soil organic carbon (SOC) and crop yields was compiled from studies published in the last decade and analyzed using descriptive and multivariate statistics and data mining techniques. Removing crop residues from the field led to average SOC contents that were 12 and 18% lower than in soils in which crop residues were retained, in temperate and tropical climates respectively. The dataset showed a wide variability as a result of the wide range of biophysical and management factors affecting net changes in SOC. In tropical climates the effect of crop residue management on SOC was subject to local climate and soil texture. In these regions the addition of C via crop residues was crucial in sustaining SOC especially in coarse textured soils. Yields increased following residue retention in tropical soils, while low SOC corresponded with lower crop production in temperate areas. Our results suggest that crop residue removal is not recommended in tropical soils, particularly in coarse-textured ones, and in SOC-depleted soils in temperate locations. Partial residue removal can be considered in temperate climates when soils are well-endowed in SOC. Future policies must consider the role of residues within different agro-ecosystems in order to advance agriculture and the bio-energy sector sustainably.

In recent years, some manufacturers have developed new downsized feller-bunchers that are particularly suited to small-tree harvesting. One of these machines was tested in some of the most promising small tree resources of Europe, namely: Finnish young conifer forests, French hornbeam coppice and Italian sycamore plantations. The tests were conducted within the scope of a 3-year long European project, whose goal was to assess the suitability of this new technology to the production of wood biomass from silvicultural operations. Depending on site characteristics, the machine reached an average productivity between 4 and 8 green tonnes per net working hour, comparing favourably with other European shear-type felling heads and qualifying for deployment on a European scale.

Several Italian and Chinese temperate lakes with soluble reactive phosphorus concentrations  20 μg C L-1 h-1) and could favor the release of inorganic phosphorus. High extracellular enzyme activities and phosphorus solubilizing bacteria abundance in sediments accelerated nutrient regeneration. In these conditions, the positive GLU-AP relationship suggested the coupling of carbon and phosphorus regeneration; an efficient phosphorus regeneration and high nitrogen levels (up to 0.067 and 0.059 mg L-1 NH4 and NO3 in Italy; 0.631 and 1.496 mg L-1 NH4 and NO3 in China) led to chlorophyll a peaks of 14.9 and 258.4 μg L-1 in Italy and China, respectively, and a typical algal composition. Conversely, in the oligo-mesotrophic lakes, very low nitrogen levels (in Italy, 0.001 and 0.005 mg L-1 NH4 and NO3, respectively, versus 0.053 and 0.371 mg L-1 in China) induced high LAP, while low phosphorus (33.6 and 46.3 μg L-1 total P in Italy and China, respectively) led to high AP. In these lakes, nitrogen and phosphorus regeneration were coupled, as shown by positive LAP-AP relationship; however, the nutrient demand could not be completely met without the supply from sediments, due to low enzymatic activity and phosphorus solubilizing bacteria found in this compartment.

In Europe the demand of biomass for the whole bioeconomy is increasing year by year. In some cases, this biomass come from non-European countries. The EU is already a net importer of biomass for bioenergy and imports could be even more relevant in the near future. Therefore, it is important to guarantee that this biomass supply from outside the EU is being done in a sustainable way and that negative environmental and socio-economic impacts are minimised. The project BioTrade2020plus has the aim of providing guidelines for the development of a European Bioenergy Trade Strategy for 2020 and beyond. It has analyzed in depth the role of lignocellulosic biomass (woody resources, agricultural residues and cellulosic crops) imports from six selected sourcing regions: North America (Southeast United States), South America (Brazil, Colombia), East Europe (Ukraine), Southeast Asia (Indonesia) and East Africa (Kenya). It has considered availability and sustainability constrains as well as existing strategies in these sourcing regions. All this info is being integrated in an interactive tool available on the BioTrade2020plus webpage. Proceedings of the 24th European Biomass Conference and Exhibition, 6-9 June 2016, Amsterdam, The Netherlands, pp. 1356-1363

Monitoring the surface composition of CO2 derived from subsurface reservoirs is an important part of the carbon capture and storage (CCS) chain. Most approaches use geochemical or geophysical instrumental approaches but these have the drawback that no long-term time series are available, which depend on a predefined monitoring location. We test a flexible approach using natural archives based on the measurement of radiogenic 14C concentrations in tree rings to detect geogenic CO2 fluxes derived from natural springs in the Latera Caldera, central Italy. The approach can be used as a preliminary check to evaluate natural CO2 leaks from sites designated for CO2 storage, as well as evaluating the extent of leakage in an unforeseen area. An extensive database of soil gas composition and fluxes is available for that site, permitting direct comparison of the tree ring isotopic composition and point sources of CO2 from the subsurface against the mean atmospheric standard. We sampled oak trees (Quercus cerris and Quercus pubescens) directly at the CO2 source (ON), and at short (50 m, NEAR), intermediate (500 m, FAR) and long distances (~3000 m, CONTROL) from CO2, sources, and measured the radioactive 14C concentration in tree rings at ~10 year intervals from 2012 back to 1976. To accurately date the tree rings we constructed a tree-ring chronology using standard dendrochronological methods. We tested whether variation in 14C concentration in tree rings and ring-width are related to distance of trees from CO2 source, as well as climate factors, i.e. precipitation and temperature. Results show that local point sources of CO2 at the location where the tree grows are effectively recorded by the 14C concentration in the cellulose of this tree. The fossil CO2 signal is sharply delineated since already at short distance from the source (~50 m, NEAR) the 14C incorporation is at the detection limit of the tested approach. Tree-ring width of the oaks at Caldera Latera is mainly limited by the amount of precipitation during the growing season, from March to October, while distance to the CO2 point source has no detectable effect on radial growth, likely due to the continuous presence of the enhanced CO2 flux to which the trees adapt their physiology from germination. While the approach is promising and permits data collection at any forested site, a more detailed sampling transect between 0 and 50 m from a point source of CO2 is needed to determine the exact detection limit of the signal in the 14C concentration of the tree ring cellulose.