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Research is needed to look for plants or lines that can thrive on soils affected by water deficit or other constraints. The present work investigated the potentiality of Saccharum spontaneum L. spp. aegyptiacum (Willd.) Hack., a lignocellulosic, perennial, rhizomatous, no-food crop in semi-arid Mediterranean area. A 3-year field trial was carried out with the aim to evaluate its physiology, biomass yield, water use efficiency, and biomass quality under different soil water availability. During 2011/2012, 2012/2013, and 2013/2014 growing seasons (hereinafter referred as 2011, 2012, and 2013, respectively), three levels of maximum evapotranspiration restitution (ETm) were compared: I 100 (100% ETm restitution), I 50 (50% ETm restitution), and I 0 (rainfed condition). Net photosynthesis, stomatal conductance, and transpiration rate were strictly related to the available soil water content (ASWC), with maximum gas exchange at field capacity. However, gas exchange between plants and atmosphere was also measured when ASWC was close to wilting point. Biomass dry matter (DM) yield and main morpho-biometric traits (e.g., stem height and basal stem diameter) were significantly affected by ASWC. A non-linear model showed that maximum DM yield, 37.86 Mg ha −1 , can be achieved when 1150 mm of water were used by the crop. Water use efficiency (WUE) was always highest in rainfed condition ( I 0 ), however, only in 2013 I 0 was significantly higher than I 50 and I 100 (5.89 g L −1 vs 4.26 and 3.33 g L −1 ). Within the variables employed, a linear model showed that WUE was negatively related to crop water use (CWU). The fiber content was not affected by the irrigation treatments. In the average, hemicellulose, cellulose, and lignin accounted for 23.9 (% w/w), 35.0 (% w/w), and 19.9 (% w/w), respectively. On the other hand, moisture and ash content, bulk density, low heating value, and ash melting point resulted significantly affected by the treatment. Present results suggested that S. spontaneum spp. aegyptiacum possesses a range of agronomically desirable traits of biomass crop: C4 plant, high biomass yield, active assimilation rates during drought–stress periods, able to use water efficiently, and satisfactory biomass quality.

A general obstacle to the development of perennial grasses is the relatively high cost of propagation and planting. The objective of the present study was to investigate new propagation and planting methods of giant reed (Arundo donax L.), miscanthus (Miscanthus x giganteus Greef et Deuter) and switchgrass (Panicum virgatum L.). Field and open-air pot trials were carried out in four different locations across Europe: hydro-seeding of switchgrass was tested in field trials at the experimental farm of the University of Bologna, Italy; stem propagation and bud activation methods of miscanthus were evaluated in field experiments in Péteri, Hungary; giant reed rhizome and stem propagations were compared in a field trial in Aliartos, Greece; finally, an open-air pot trial was carried out in Catania, Italy, using single-node stem cuttings of giant reed. Hydro-seeding emerged as a feasible and promising technique for switchgrass to ensure prompt seed emergence and weed control during plant establishment. Direct stem plantings of miscanthus were successful, and activated stem-buds were able to sprout in field conditions; however, timely stem transplant was determinant for shoot density and biomass yield. In giant reed, rhizome propagation showed a higher stem density and biomass yield than stem propagation; however, the yield gap was not significant from the second year onwards. Single-node rooting was mainly driven by air temperature. Nodes from basal stems showed higher rooting rates than median and apical ones. Growth regulator pretreatments enhanced rooting rate only at transplanting times under suboptimal air temperatures. In general, these experiments provided insights into propagation strategies aimed at enhancing the establishment phase of perennial grasses.

Within a framework of renewed interest in crambe (Crambe abyssinica Hochst ex R.E. Fries) sourcing raw materials for the bio-based industry, the adaptability and productive performances of this oil crop have been evaluated under contrasting Mediterranean environments (i.e., a fertile site in the northern part of Po valley vs. a semi-arid site of southern Sicily) during two consecutive growing seasons, aiming at its possible stable introduction in this area. The trial set in northern Italy compared three commercial varieties of crambe (Galactica, Nebula and Mario) in spring sowing, while in southern Italy only the var. Mario was tested with autumn sowing. Regardless of location and variety, thermal time for maturity was quite stable (1200–1400°C), and the crop provided satisfactory seed yields (grand mean 2.29Mghulledseedsha−1), with average oil content of ∼400gkg−1 (on dehulled seeds) and ∼52% of erucic acid. Significantly higher seed and oil yields were reached in northern than in southern Italy. Furthermore, crambe thermal use efficiency (THUE) was also higher in the north than in the south, possibly due to better environmental adaptability of the crop. The limited intraspecific variability within crambe was confirmed, with better productive performances showed by the domestic selection Mario. Promising traits were revealed in Nebula, showing greater seed weight, root length density and area, and thinner roots, although the root growth of crambe was generally modest compared with modern high erucic acid rapeseed hybrids. Available crambe varieties could be efficiently included in crop rotations across a wide range of environments within the Mediterranean basin. The short growth cycle represents an outstanding added value for this species, allowing the avoidance of prolonged drought and heat stress typical of late spring/early summer months under the Mediterranean climate. However, increased yields are needed to meet the market requests; nonetheless, the little genetic variability suggests that there is large scope for future breeding improvements, maybe exploiting advanced techniques to improve the existing genetic resources.

Energy crops, and in particular oil crops, could be an important occasion for developing new non food production rows for a new multi-functional agriculture in Italy. In this view, the use of local biomass is a fundamental starting point for the development of a virtuous energy chain that should pursue not only agricultural profitability, but also chain sustainability and that is less dependent on the global market, characterized by instability in terms of biomass availability and price. From this perspective, particular attention must be paid to crop choice on the basis of its rusticity and of its adaptability to local growing conditions and to low input cropping systems. In this context, alike woody and herbaceous biomasses, oil crops such as sunflower and rapeseed should be able to support local agricultural bioenergy chain in Italy. In addition, in a local bioenergy chain, the role of the farmers should not be limited just to grain production; but also grain processing should be performed at farm or consortium level in oilseed extraction plants well proportioned to the cropped surface. In this way, by means of a simple power generator, farmer could thus produce its own thermal and electric energy from the oil, maximizing his profit. This objective could also be achieved through the exploitation of the total biomass, including crop residues and defatted seed meals, that may be considered as fundamental additional economic and/or environmental benefits of the chain. This paper reports some results of three-years on-farm experiments on oil crop chain carried out in the framework of "Bioenergie" project, that was focused to enhance farmers awareness of these criteria and to the feasibility at open field scale of low-input cultivation of rapeseed, sunflower and Brassica carinata in seven Italian regions. In several on-farm experiences, these crops produced more than 800 kg ha-1 of oil with good energy properties. Defatted seed meals could be interesting as organic fertilizers and, in the case of B. carinata, as a biofumigant amendment that could offer a total or partial alternative to some chemicals in agriculture. Furthermore, biomass soil incorporation could contribute to C sequestration, catching CO2 from atmosphere and sinking a part in soil as stable humus. Finally, four different open field experiences carried out again in the second year of the project, have been analysed in order to evaluate their energy and greenhouse gasses balance after cultivation phase.