Analysis of spatio-temporal Bactrocera oleae (Diptera, Tephritidae) infestation distributions obtained from a large-scale monitoring network and its importance to IPM

Bactrocera oleae is the key-pest considered in the “Olive-oil quality improvement project” in Tuscany (Italy). In this region, a network of 286 representative farms has been created in 2002 for monitoring weekly olive fruit-fly infestations, and the obtained data have been used in advising farmers on B. oleae control. The field observations were made by the regional extension service, and data have been collected from an internet-based monitoring network implemented in the Landscape Entomology Laboratory (LELab) of Scuola Superiore Sant’Anna. In this paper, we rely on the Geographic Positioning System (GPS) to locate the monitoring farms and make use of farm-specific information to analyze the regional spatial pattern of B. oleae infestions. Data analysis has been performed with Arcview 8.2, and we used variograms to model autocorrelations between sample points and cross-validation to identify the most reliable index. We consider the utility of Geographic Information System for spatial analysis at the landscape (or large) scale and kriging technique to interpolate between sample points. The resultant map can be used to predict the beginning of B. oleae infestations

Soil conservation and ecosystem services from agroforestry systems: a GIS-based approach for soil erosion in Central Italy

Preserving natural resources, such as soil, is one of the major challenge for agriculture, in the view of developing sustainable adaptation strategies to climate change. Soil loss by water erosion is a critical issue in the Mediterra - nean region due to high rainfall erosivity caused by the increased frequency of extreme precipitation events. In Tuscany, the risk of soil erosion is exacerbated on arable soil of hilly areas, where the persistent application of conventional tillage is associated with: (i) long periods with bare soils within the crop rotation, (ii) poor herba- ceous vegetation cover due to low biomass productivity and (iii) scarce presence of trees on farmland. Agrofore - stry systems - “the practice of deliberately integrating woody vegetation (trees or shrubs) with crop and/or ani- mal systems to benefit from the resulting ecological and economic interactions” - can reduce soil erosion risk by enhancing cover-management factor. In this study the (R)USLE (Revised Universal Soil Loss Equation) was im- plemented on a GIS-based model in order to assess the potential of diferent agroforestry systems in decreasing soil erosion risk on arable land below the tolerance threshold (11 Mg ha-1 yr-1). The JRC-EU map proposed by Pa- nagos et al. (2015) was used for rainfall erosivity, whereas the agroforestry P-factor values were derived from Delgado & Canter (2012). The reference scenario, based in current soil uses (Corine Land Cover 2012) allowed to determine the baseline of potential soil losses on arable land in Tuscany and to identify areas characterized by the highest risk of erosion. About 50% of the cropland in the study area, 450,000 ha, has a severe soil erosion risk, more than 33 Mg ha-1 yr-1 of soil loss.The development of alternative scenarios, based on the possible implemen- tation of agroforestry systems, allowed to highlight that: (i) alley cropping systems (P-factor from 0.1 to 0.5) would reduce soil loss rate under the tolerance threshold on 60 % of the arable land of Tuscany; (ii) the 11% of the arable land would urgently need high conservative agroforestry practices (P-factor less than 0.1) in order to reduce soil loss below the tolerance threshold

Microwave-assisted FeCl3-catalysed production of glucose from giant reed and cardoon cellulose fraction and its fermentation to new generation oil by oleaginous yeasts

The replacement of fossil fuels and materials with biofuels and bioproducts is a crucial current global goal. Biorefining of lignocellulosic biomass generates pentose and hexose sugars which can be converted into several added-value bio-based compounds. Among biofuels, biodiesel is one of the most promising renewable energy sources since it does not require new technology and engines for its use. Traditional biodiesel is produced on the industrial scale starting from vegetable oils obtained from oleaginous crops, such as palm oil, rapeseed oil and sunflower oil. However, most of the oleaginous plant species are food crops, determining the ethical debate on the right use of these renewable resources and the competition between the energy industry and food chain. An innovative and promising solution is represented by single cell oil (SCO) produced from oleaginous yeasts. This new generation oil, if obtained from low or negative value industrial waste, represents a promising platform chemical for the production of biodiesel, biosurfactants, animal feed and biobased plastics [1]. This study investigated the microwave-assisted FeCl3-catalysed hydrolysis of giant reed (Arundo donax L.) and defatted cardoon (Cynara cardunculus L.) cellulose fractions to give glucose. Giant reed is a promising energy crops able to grow on marginal lands, while cardoon stalks are the crop residue in the production of vegetable oil. A preliminary acid pretreatment was adopted for giant reed [2], while steam-explosion pretreatment was performed on cardoon [3], both allowing a significant removal of xylan fractions. Under different reactions conditions, the microwave-assisted FeCl3-catalysed hydrolysis converted the two pretreated feedstocks into glucose-rich hydrolysates which were employed as fermentation medium for the production of SCO by the oleaginous yeast Lipomyces starkeyi DSM 70296. For giant reed, the low production of furanic compounds enabled the direct fermentation of undetoxified hydrolysates, while for cardoon the furfural removal was necessary before the fermentation step. After hydrolysis, for both hydrolysates the fermentation provided promising lipid yields (~14 wt%) and oil content (~25 wt%). Figure 1 shows the process layout of the implemented third-generation biorefinery scheme. The SCO appears a valid candidate for the production of new generation biodiesel with good oxidative stability and cold flow properties. Moreover, it resulted very similar to palm and rapeseed oils, usually employed as a renewable source for the production of traditional biodiesel

Aboveground Yield and Biomass Quality of Giant Reed (Arundo donax L.) as Affected by Harvest Time and Frequency

Giant reed (Arundo donax L.) is a perennial rhizomatous grass producing high biomass yields in temperate and warm climates under rainfed and reduced input conditions. Harvest time and frequency typically affect the productivity and suitability for energy conversion of energy crops. In order to evaluate the effect of different cutting managements on biomass yield and quality of giant reed, three single harvest (SH) and six double harvest (DH) systems were compared. Biomass yield, leaf mass ratio, dry matter (DM), and ash content were assessed for each harvest. Over the 2 years of study, giant reed demonstrated good productivity levels both when harvested once a year and twice a year (about 30 Mg ha−1) without significant differences between the treatments. Regarding double-cut regimes, overall yields were significantly reduced by delaying the second cut from autumn to winter (32.9 vs 30.2 Mg ha−1), and the percentage of the first cut with respect to the overall yield varied from 55 to 80 %. Biomass quality was also significantly affected by harvest time and frequency. The biomass obtained in double harvest systems showed higher average moisture levels (about 40 % DM) and ash concentrations ranging from 4.7 to 8.7 %. In contrast, single harvest systems led to a drier biomass (47–57 % DM) and reduced mineral contents (3.4–4.8 % ash). The feasibility of double-cut management should therefore be considered in terms of the specific giant reed-based supply chain, with particular regards to the storage and conversion technology adopted

Light reduction affected agronomic performance and nutritive value of temporary grassland swards in a Mediterranean rainfed plot trial

In Italy, traditional olive orchards are characterised by low tree density (100-300 ha-1) allowing the cultivation of forage and crops under the tree canopy (Paris et al., 2019). Eichhorn et al. (2006), reported that in Central Italy there are 20000 ha of farmland identified as a silvoarable olive orchard. The intercropping of perennial legumes and trees is a key strategy to improve nutrient cycle of silvoarable systems, due to the higher amount of nitrogen (N) accumulated in stable forms in soil due by biological nitrogen-fixation (Hernandez-Esteban et al., 2019; Sanna et al., 2019), leading to a request for reduction of inorganic N fertilisation. Perennial legumes can also provide a continuous soil cover during the entire year reducing soil loss risk (Vallebona et al., 2016). In the Mediterranean basin, the most important perennial legume is alfalfa (Medicago sativa L.). Previous studies reported that alfalfa nutritive value was not negatively affected by tree presence (Mantino et al., 2021), whereas legume production was reduced due the competition for resources such as water (Nasielski et al., 2015), nutrients (Isaac et al., 2014) and light (Mantino et al., 2021). In Tuscany, sulla (Hedysarum coronarium L.) an autochthonous biennial legume is appreciated for its rusticity, productivity, and quality and it is intercropped with Italian ryegrass (Lolium multiflorum Lam.) for a better utilisation as pasture. In 2019, a rainfed field plot trial was established to evaluate agronomic performance and nutritive value of different perennial forage species grown under different levels of light reduction, aiming to start a selection of shade tolerant forage crops. In October, the plot trial was established in Pisa, on a clay-loam soil with pH of 8.1 and 2.5 % w/w of organic matter content in the topsoil (0-0.3 m). Before sowing, 100 kg ha-1 of P2O5 were applied. The experimental layout complies with a two-factor randomized complete block design with four replicates (18 m2 sizing each plot). The first factor included five different swards: i) sulla cv. Silvan, (ii) ryegrass cv. Teanna, (iii) mix of sulla cv. Silvan and ryegrass, 50:50 (iv) mix of sulla cv. Silvan, sulla cv. Chiara Stella and sulla cv. Bellante 33:33:33 and (v) alfalfa cv. Messe. The second factor included three increasing shading levels: S0) the control representing full light availability, S25) and S50), corresponding to a reduction of potential light availability of 25 and 50% respectively. As previously tested by Varella et al. (2011), shading was provided by woody slats, N-S oriented, 2.0 m long and 0.10 m wide, with a distance between each slat of 0.10 m for S50 and 0.20 m for S25, covering a total surface of 4 m2. After sowing, slats were placed at 0.8 m above ground level. Yield and nutritive value of herbage mass and N2 fixation were evaluated for two consecutive years. Herbage biomass was not affected by the reduction of the 50% of light in ryegrass and ryegrass-sulla mixture while it was negatively affected in alfalfa and sulla. Conversely, the 25% of shade level had no effect on legume yield

Double row spacing and drip irrigation as technical options in energy sorghum management

The effect of two row spacing configurations and four water supply levels was investigated on sweet and fibre sorghum in Central Italy for two consecutive years. Results highlighted the influence of both irrigation and row spatial configuration on crop productivity. Indeed, several studies have pointed out the positive response of sorghum to irrigation in Mediterranean climate, as in this environment water stress represents one of the main limiting factors on crop productivity. On the other hand, few attempts have been made to explore the role of row spacing on energy sorghum productivity. Results outlined an average increase in sorghum dry biomass yield ranging from +23% to +79% at variable rates of water supply as compared to rainfed control. The positive effect of irrigation was also observed on leaf area index and radiation use efficiency. Moreover, we observed a crop yield increase, from 9% to 20%, under double row spacing compared to the standard planting pattern ( i.e. single row spacing). Finally, it was confirmed the efficient use of water by sorghum and the great ability of sorghum to increase its biomass yield in response to increasing volumes of water supplied. Therefore, this work suggests how row spacing configuration and drip irrigation could be feasible technical options to increase sorghum biomass yields in Mediterranean environments. These techniques should be experienced by farmers towards a sustainable intensification of current cropping systems

Alfalfa (Medicago sativa l.) overseeding on mature switchgrass (panicum virgatum l.) stand: Biomass yield and nutritive value after the establishment year

Perennial crops can positively act on the environment providing a better inter-annual protection of soil cover from water erosion, limiting soil fertility degradation, the risk of nutrient leaching and the exploitation of water for irrigation. Switchgrass (Panicum virgatum L.), a warm-season grass native from North America, has been cultivated for decades as forage crop and only recently as bioenergy crop. Even if several studies reported a positive effect of nitrogen (N) supply on switchgrass yield and quality, potential indirect and direct environmental risks (e.g., eutrophication and greenhouse gas emission) are related to this practice. For this reason grass-legume intercropping can represent a sustainable practice able to increase biomass yield and quality, and at the same time to improve N use efficiency, soil structure and fertility. Based on this, the aim of this study was to evaluate the suitability of switchgrass to Mediterranean environment as forage crop and to improve biomass yield and its nutritional value by intercropping with alfalfa (Medicago sativa L). During spring 2013, in two switchgrass pure stands (varieties Alamo and Blackwell, respectively), alfalfa was established through direct seeding implementing a split-plot experimental design. Our first year results report a positive effect of the intercropping in increasing the total annual yield of the stand, of about 20% with respect to the pure switchgrass stand. However, the presence of alfalfa negatively affected switchgrass yield in the mixture. In both varieties, the crude protein content was higher in the mixture than in the pure switchgrass stands. Conversely, the neutral detergent fibre content in the mixture was lower than in pure switchgrass. Then, our results show that switchgrass-alfalfa intercropping leads to increase the profitability of grassland-based livestock production