• Energy Research

A major constrain for sweet sorghum (Sorghum bicolor L. Moench) establishment as a reliable biofuel feedstock is the fast biomass degradation immediately after harvest due the high content of soluble sugars and their rapid fermentation that considerably decrease the actual ethanol yield. Such a drawback does not allow storing of sorghum for a reasonable period forcing the industry to process it immediately with consequent problems of handling, logistic, and plant size. Therefore, an appropriate harvesting and storage technique to prevent sweet sorghum juice degradation is urgently needed to ensure economic benefits to farmers. An efficient and cost-effective way to overcome this obstacle could be an on-farm storing system of undistilled ethanol from sweet sorghum juice, while the remaining bagasse could be ensiled and exploited for complementary energy generation. The objective of this study was to evaluate different harvest methods and storage techniques aiming to a low cost and efficient on-farm processing systems to store sweet sorghum biomass. Harvesting in the hard dough stage and defoliating the plants before juice extraction resulted in higher ethanol yield. The use of commercially available fructophilic yeasts allows maximizing undistilled ethanol yield and on-farm storing for about 1 year without spoilage. The residual bagasse was ensiled and inoculated with Lactobacillus bacteria commonly used in forage conservation which significantly improved its quality as feedstock for biogas fermenters. In conclusion, the integration of low-cost harvesting and storage techniques with the valorization of sweet sorghum by-products are worthwhile management strategies to be further developed.

The main objective of the BECOOL project “Brazil-EU Cooperation for Development of Advanced Lignocellulosic Biofuels” is to strengthen EU-Brazil cooperation on advanced lignocellulosic biofuels. The project covers the whole value chain, from biomass production, to logistics and conversion. In the BECOOL project, credible, cost-effective and sustainable value chains for several biomass types will be evaluated. The streamline along each value chain, from the raw material to the final energy product/carrier, will be identified, taking into account cultivation, harvesting, logistics and conversion technologies.This paper is focused on the implemented biomass production and diversification strategies. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 207-208

Relay cropping is an innovative cropping system where food/feed crops and dedicated lignocellulosic crops could be produced in the same land and growing season without competition issues. The objective of this study was to evaluate the effects of a dedicated lignocellulosic legume crop on relay planted wheat productivity. Wheat grain yield, bread making quality, and straw production were improved, while the cumulated biomass yield (sunn hemp biomass + wheat straw) arrived to comparable productivity levels of some high yielding perennial grasses (i.e. giant reed). These results suggest that relay cropping could be a sustainable cropping system to integrate food and dedicated biomass crops production. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 99-101

The main objective of the BECOOL project “Brazil-EU Cooperation for Development of Advanced Lignocellulosic Biofuels” is to strengthen EU-Brazil cooperation on advanced lignocellulosic biofuels. The project covers the whole value chain, from biomass production, to logistics and conversion. In the BECOOL project, credible, cost-effective and sustainable value chains for several biomass types will be evaluated. The streamline along each value chain, from the raw material to the final energy product/carrier, will be identified, taking into account cultivation, harvesting, logistics and conversion technologies. This paper is focused on the implemented biomass production and diversification strategies. Proceedings of the 27th European Biomass Conference and Exhibition, 27-30 May 2019, Lisbon, Portugal, pp. 276-280

Enhancing agricultural multifunctionality is viable in a multi-purpose crops intensification scenario. The cultivation of a sequence of food and energy crop has the potential to strengthen the crop rotation effect without reducing food land. Annual lignocellulosic crops for advanced biofuel could be introduced alongside conventional crops during the periods of the year on which the latter ones are not cultivated thus to increase the period of utilization of the land unit (increased LER). In this study a preliminary assessment of the effect of four dedicated lignocellulosic crops (sunn hemp, fiber sorghum, kenaf, and hemp) on a subsequent cereal is given in terms of biomass yields. The dedicated lignocellulosic crops have been tested within conventional sequential crop rotations (maize - wheat rotation). Preliminary results indicate that biomass sorghum and kenaf produced the highest and lowest yields, respectively. Whereas industrial hemp and sunn hemp were intermediate to such extremes. Kenaf negatively affected the yield of the subsequent wheat straw that decreased compared to the industrial hemp and sunn hemp by 15%. Whereas the production of wheat straw after biomass sorghum and conventional rotation was intermediate. This preliminary finding indicates that depending on the species characteristics it would be possible to introduce dedicated lignocellulosic crops within conventional crop rotations. Moreover, the biomass characterization highlighted whether the investigated feedstocks were suitable to thermo/biochemical conversion. Further investigations, however, are required to assess the overall systems feasibility and sustainability. Proceedings of the 28th European Biomass Conference and Exhibition, 6-9 July 2020, Virtual, pp. 1016-1018

Enhancing the multitasking of traditional agriculture is a key strategy to fulfil the Horizon 2020 targets. Sunn hemp, cultivated as an energy crop within the traditional rotations gap, represents an ambitious challenge for the coexistence of food and non-food crops without competition. The short time available for soil tillage between consecutive crops in rotation could be extended through quicker and more economical seedbed preparation. Three soil management practices were compared in this study: no- (NT), minimum (MT) and conventional (CT) tillage. Even though the non-statistical differences in the average dry biomass, the NT treatment resulted 27% higher than the CT. Furthermore crop yield and architectural components of the plants such as emergence rate, number of plants, canopy cover, and plant height increased by 25%, 33%, 32%, and 20%, respectively under NT conditions in comparison to CT. Moreover branching rate was reduced by two to six times. Besides generating a better plant performance since the emergence stage, the better biometric canopy characteristic of the NT treatment offer improved agronomic harvest characteristic without a yield reduction. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 366-368

Proper soil fertility maintenance is an issue of significant importance because of its impacts on crop productivity, production costs, and on the environment. The objective of the present study was to determine the long­term effects (13 years) of several nitrogen fertilization doses on the aboveground biomass production of giant reed. A local ecotype of giant reed was planted in 1997 in Bologna (Italy) at a density of one plant per square meter. Every year, starting from the second one, four nitrogen fertilization rates were applied: 0 (N0, unfertilized control), 80 (N80), 160 (N160), and 80+80 (N80+80) kg N ha-1. Nitrogen was applied one week after 50% of re-sprouting in the N80 and N160 treatments, while in the N80+80 treatment, nitrogen application was split in two: 80 kg N ha-1 were applied at the same time as in the previous treatments, while the remaining dose was applied two weeks later. Winter harvests were done manually and aboveground dry matter was determined. Also plant height and basal stalk diameter were measured. The unfertilized plants reached their maximum productivity (23.4 Mg ha-1) on the 4th year after planting (one year earlier than in the fertilized plots), afterwards a quasi-continuous yield reduction up to 10.8 Mg ha-1 was observed. On the other hand, in the N160 and N80+80 treatments productivity was characterized by two yielding phases: in the first one maximum yields (between 26.1 and 27.7 Mg ha-1) were obtained on the 5th year, then yields reduced in the next two years. During the second phase biomass production increased again from the 8th to 10th year of growth, but with somewhat lower values than in the first phase, then productivity declined towards the last harvest, reaching values similar or even lower than in the establishment year. These results suggest that high fertilization rates sustained yields over 20 Mg ha-1 for a productive cycle of about 8 years. If no fertilization is applied the high yielding production cycle is circumscribed to about 3 years only. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 152-156

Although the mechanisms of sorghum and maize adaptation to drought are generally well understood, little is known about the response of newly developed sweet sorghum genotypes to water deficits, especially at the root level. Thus, the objective of this study was to determine the rooting and canopy characteristics of a sweet sorghum hybrid, Sucro 506, compared to ethanol maize at two levels of water restoration. Root growth was correlated to the above ground biomass and to some physiological traits related to drought resistance. The trial was set up in a total of 20 cubic rhizotrons, where calibrated soil moisture probes were installed for monitoring and adjusting the soil moisture content in the well­watered and dry treatments to 25% and 12% (v/v), respectively. The preliminary results show that under drought conditions sweet sorghum was more able than maize to sustain its physiological activity closer to that of the well­watered plants. Droughted sweet sorghum had higher leaf area, above and belowground biomass, and WUE than maize. The accumulated aboveground dry biomass of droughted sorghum was 62% of that produced under well­watered conditions, while that of maize was only half. Moreover, in contrast to maize the root length density of droughted sorghum was enhanced, especially in deep soil layers. These results suggest that the deep and well developed root system of sweet sorghum under drought stress allows it to sustain growth, development, and physiological activity somewhat similar to its potential. Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 195-199