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The transition from conventional arable towards silvoarable systems can increase the delivery of ecosystem services. Nevertheless, the assessment of crop yield under agroforestry condition is crucial to evaluate of the reliability of these systems and to increase the knowledge base needed to support their design. Although the feasibility of poplar short rotation coppice (SRC) silvoarable alley-cropping systems has been widely investigated, few studies have addressed the agronomic response of crops intercropped with poplar SRC in narrow alleys, especially in Mediterranean environments. Thus, this paper treats the effects of SRC poplar rows on soybean and sorghum productivity in a 2-year rotation implemented in an alley-cropping system. A field experiment was carried out in 2018 and 2019 with the objective of measuring and evaluating effects of light availability variation, as affected by the growing rate of 2-year coppice cycle poplar SRC rows, and the soil characteristics on soybean-sorghum and sorghum–soybean rotations. Above-ground biomass, grain yield and crops residue showed a significant reduction in the tree–crop interface up to 74% and sorghum proved to be less tolerant to light reduction compared to soybean. Our results demonstrated that light is the most important factor for sorghum cultivation, despite grain yield was also influenced by the soil characteristics such as pH, while soybean is affected also by soil moisture and water retention capacity. The design of crop rotation in an SRC-based agroforestry system needs to consider the different agronomic performance of different crops and the harvest cycle of tree rows. [ABSTRACT FROM AUTHOR]

This study examined the effect of harvest time (from May to September) and dry matter partitioning on biomethane potential and methane yield per unit area of Phragmites australis cultivation under paludiculture conditions. The experimental site is part of a larger experimental platform (San Niccolò, Pisa) located within the Massaciuccoli Lake Basin in Central Italy (Tuscany, IT). The study also took into account the double cut strategy by evaluating the regrowth from June to September. Biomethane potentials ranged from 384 to 315 and from 412 to 283 NL CH kg VS (normal liters of methane per kg of volatile solids) for leaves and stems, respectively. About digestion kinetics, maximum daily production rate ( R ) was significantly affected by harvest time and not by plant partitioning. Along the harvest season, biomethane yield per unit area was mostly driven by the biomass yield showing an increasing trend from May (1659 Nm ha) to September (3817 Nm ha). The highest value was obtained with the double harvest option (4383 Nm ha), although it was not statistically different from the single harvest carried out in September. Owing to its remarkably lower yields, P. australis cannot be considered along the same lines as crops conventionally used for biogas production, but it may represent an interesting option for paludiculture cropping systems by coupling peatland restoration with bioenergy production. September harvest management seemed the most feasible option, although further investigation on crop lifespan is needed. [ABSTRACT FROM AUTHOR]

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) 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), 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. [ABSTRACT FROM AUTHOR]

Highlights: [•] The Biochemical Methane Potential (BMP) of giant reed was assessed. [•] Biochemical Methane Potential was significantly influenced by harvest time and frequency. [•] The highest BMP and the best digestion kinetics was achieved at juvenile crop stages. [•] Double harvesting increased by 20–35% the methane yield per hectare. [ABSTRACT FROM AUTHOR]