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Diosgenin wastewater produced from Dioscorea zingiberensis C. H. Wright in diosgenin enterprise is the by-product of numerous operations chiefly including washing raw materials, acid hydrolysis, and cleaning the apparatus with water. It requires the removal of high concentrations of various organic and inorganic contaminants from this wastewater in order to avoid pollution to the environment and fresh water system. Currently, several different methods such as chemical, physicochemical, biological recovery resource, constructed wetland, and integrated methods of these processes are being applied for treating diosgenin wastewater. Aiming to get a comprehensive overview, available reports from experimental scale to industry scale about the treatment of this wastewater were collected and summarized. Therefore, this review paper will provide appropriate choice for the efficient treatment of diosgenin wastewater and supportive information for the other scientists who want to continue this valuable research in the future. [ABSTRACT FROM AUTHOR]

For the past decade, Thailand pursued a strategy of promoting biofuel crop production, including sugarcane, to meet the ever increasing energy demand and to increase the income of farmers. This study analyzed the influence of policy instruments implemented to promote the sugarcane cultivation, farm household socioeconomic levels, biophysical, and institutional factors driving the conversion of rice fields into sugarcane farms. Primary information was collected from 230 farm households through a structured questionnaire. Relevant policy documents published by the responsible government agencies were the main sources of secondary information collected for policy analysis. The analyses revealed that farmers in the study area converted 25-75% of their rice fields into sugarcane farms as a result of implementation of policy instruments that made sugarcane financially far more attractive than rice. The results of the regression analysis showed that eight variables were found significant and positively influenced the conversion of rice fields into sugarcane farms. These were access to extension services, information, sugarcane loading stations, and ground water for irrigation, and duration of experience in sugarcane farming as well as household head's age and education. Irrespective of landholding size, the majority of farmers were not concerned about food security. In view of the finding, if feasible, in the form of additional price supports and commercial cane sugar index-based pricing strategies to promote sugarcane production should benefit all concerned farmers. Likewise, attention should be paid to deliver essential extension and marketing services in an effective way, particularly to those farmers who are not receiving such services. [ABSTRACT FROM AUTHOR]

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In light of rising energy costs, lignocellulosic ethanol has been identified as a renewable alternative to petroleum-based transportation fuels. In an attempt to reach government mandated ethanol production levels, potential plant biofeedstock candidates have been investigated, and cold-tolerant, perennial accessions within the C4 grass genus Miscanthus have been identified as leading contenders in the Midwestern US. To facilitate the development of improved cultivars through marker-assisted breeding, a quantitative trait locus ( QTL) study was conducted on a full-sib, F1 mapping population segregating for flowering time, height, leaf width, and yield using a genetic map consisting of 846 segregating SNP and SSR markers. This was a 3 year study investigating the genetic architecture underlying traits important to biomass production in a population of 221 progeny from a cross between M. sinensis 'Grosse Fountaine' and M. sinensis 'Undine' established in the spring of 2010; 72 QTLs with LOD scores above the genome-wide, permuted threshold equivalent to a P-value of 0.05 were identified across 13 traits. Of the 36 QTLs identified in 2011, 22 were detected again the following year. Both the use of spring emergence and vigor rating as a covariate to account for variation related to differences in establishment increased the power to detect QTLs in the 2 year establishment period. Finally, a dry period in the middle of the 2012 growing season suggested that yield declines were due to a decrease in tiller diameter. [ABSTRACT FROM AUTHOR]

The expected use of solid biomass for large-scale heat and power production across North-West Europe ( NW EU) has led to discussions about its sustainability, especially due to the increasing import dependence of the sector. While individual Member States and companies have put forward sustainability criteria, it remains unclear how different requirements will influence the availability and cost of solid biomass and thus how specific regions will satisfy their demand in a competitive global market. We combined a geospatially explicit least-cost biomass supply model with a linear optimization solver to assess global solid biomass trade streams by 2020 with a particular focus on NW EU. We apply different demand and supply scenarios representing varying policy developments and sustainability requirements. We find that the projected EU solid biomass demand by 2020 can be met across all scenarios, almost exclusively via domestic biomass. The exploitation of domestic agricultural residue and energy crop potentials, however, will need to increase sharply. Given sustainability requirements for solid biomass as for liquid biofuels, extra- EU imports may reach 236 PJ by 2020, i.e., 400% of their 2010 levels. Intra- EU trade is expected to grow with stricter sustainability requirements up to 548 PJ, i.e., 280% of its 2010 levels by 2020. Increasing sustainability requirements can have different effects on trade portfolios across NW EU. Excluding pulpwood pellets may drive the supply costs of import dependent countries, foremost the Netherlands and the UK, whereas excluding additional forest biomass may entail higher costs for Germany and Denmark which rely on regional biomass. Excluding solid biomass fractions may create short-term price hikes. Our modeling results are strongly influenced by parameterization choices, foremost assumed EU biomass supply volumes and costs and assumed relations between criteria and supply. The model framework is suited for the inclusion of dynamic supply-demand interactions and other world regions. [ABSTRACT FROM AUTHOR]

Ukraine was once considered the breadbasket of the Soviet Union, its agriculture subject to both extensification and intensification measures. Following the dissolution of the Soviet Union, both these processes were reversed, giving modern-day Ukraine the image of untapped agricultural potential. Alongside the country's proximity to the European Union and its access to the Black Sea, this has made Ukraine a key candidate as a global supplier of feedstock for biofuel. Demand for the latter is rising noticeably, especially in the wake of current European and international blending targets for liquid biofuels. Ukraine has responded with a number of initiatives to further biofuel feedstock production. We have compiled a material flow account for Ukraine, focusing especially on the development of the agricultural sector since the early 1990s. By complementing this physical account with an in-depth analysis of political and economic developments, we are able to trace the impact of rising demand for biofuel feedstock on Ukraine. We find that the attempt to establish a biofuel sector based largely on rapeseed was not successful but has nonetheless left the country at a cross-road in the development of both its economy and its resource use. [Copyright &y& Elsevier]

Highlights: [•] Phosphorous loads are predicted to 2040 from Great Lakes tributaries. [•] Land use change will produce increases in phosphorous loads of up to 9.5%. [•] Watersheds most vulnerable to phosphorous source increases are identified. [Copyright &y& Elsevier]

Abstract: Although perennial grasses show considerable potential as candidates for lignocellulosic bioenergy production, these crops exhibit considerable variation in regional adaptability and yield. Giant miscanthus (Miscanthus × giganteus Greef & Deuter), Miscanthus sinensis Anderss. ‘Gracillimus’ and MH2006, plume grass (Saccharum arundinaceum Retz.), ravenna grass (Saccharum ravennae (L.) L.), switchgrass (Panicum virgatum L. ‘Alamo’), and giant reed (Arundo donax L.) field plots were established in 2008, treated with four nitrogen (N) fertilizer rates (0, 34, 67, 134kgha−1 y−1), and harvested annually in winter from 2008 to 2011. Giant reed, ‘Gracillimus’, switchgrass, MH2006, giant miscanthus and ravenna grass at the Mountain site produced mean dry matter yields of 22.8, 21.3, 20.9, 19.3, 18.4, and 10.0 Mgha−1 y−1, respectively (averaged over the last two years). Dry matter yields at the Coastal site for giant reed, giant miscanthus, switchgrass, ravenna grass, and ‘Gracillimus’ were 27.4, 20.8, 20.1, 14.3, and 9.4 Mgha−1 y−1, respectively (averaged over the last two years). Increasing N rates up to 134 kgNha−1 did not have a consistent significant effect on biomass production. High yields coupled with high mortality for plume grass at both sites indicates its potential as a bioenergy crop and need for continued improvement. Overall, the perennial grasses in this study had low nutrient removal, although giant reed and plume grass often removed significantly more N, P, K and S compared with Miscanthus spp. and switchgrass. Our results indicate that giant reed, giant miscanthus, and switchgrass are productive bioenergy crops across geographic regions of North Carolina. [Copyright &y& Elsevier]

This study presented life cycle water footprints (WFs) of biofuels from biomass in China based on the resource distribution, climate conditions, soil conditions and crop growing characteristics, life cycle WFs including blue, green and gray water were evaluated for the selected fuel pathways. Geographical differences of water requirements were revealed to be different by locations. The results indicated that water irrigation requirements were significantly different from crop to crop, ranging from 2- 293, 78-137, and 17-621 m3/ha, for sweet sorghum, cassava, and Jatropha curcas L., respectively. Four biofuel pathways were selected on this basis to analyze the life cycle WF: cassava based bioethanol in Guangxi, sweet sorghum based bioethanol in Northeast China, Jatropha curcal L. based biodiesel in Yunnan and microalgae based biodiesel in Hainan. The life cycle WFs of bioethanol from cassava and sweet sorghum were 3708, and 17 156 m3 per ton of bioethanol, respectively, whereas for biodiesel produced from Jatropha curcas L. and miaroaigae, they were 5787, and 31 361 m3 per ton of biodiesel, respectively. The crop growing stage was the main contributor to the whole life cycle of each pathway. Compared to blue and green water, gray water was significant due to the use of fertilizer during die growing of biomass. From the perspective of the WF, cassava based bioethanol in Guangxi and Jatropha based biodiesel in Yunnan were suitable for promotion, whereas die promotion for microalage based biodiesel in Hainan required improvement on technology. [ABSTRACT FROM AUTHOR]

Biomass produced from perennial energy crops is expected to contribute to UK renewable energy targets, reducing the carbon intensity of energy production. The UK government has had incentive policies in place targeting both farmers and power plant investors to develop this market, but growth has been slower than anticipated. Market expansion requires the interaction of farmers growing these crops, with the construction of biomass power plants or other facilities to consume them. This study uses an agent-based model to investigate behaviour of the UK energy crop market and examines the cost of emission abatement that the market might provide. The model is run for various policy scenarios attempting to answer the following questions: Do existing policies for perennial energy crops provide a cost-effective mechanism in stimulating the market to achieve emissions abatement? What are the relative benefits of providing incentives to farmers or energy producers? What are the trade-offs between increased or decreased subsidy levels and the rate and level of market uptake, and hence carbon abatement? The results suggest that maintaining the energy crop scheme, which provides farmers' establishment grants, can increase both the emissions abatement potential and cost-effectiveness. A minimum carbon equivalent abatement cost is seen at intermediate subsidy levels for energy generation. This suggests that there is an optimum level that cost-effectively stimulates the market to achieve emissions reduction. [ABSTRACT FROM AUTHOR]

In the last half-decade, sharp jumps in the prices of wheat, rice, and corn, which furnish about two-thirds of the calorie requirements of mankind, have attracted worldwide attention. These price jumps in grains have also revealed the chaotic state of economic analysis of agricultural commodity markets. Economists and scientists have engaged in a blame game, apportioning percentages of responsibility for the price spikes to bewildering lists of factors, which include a surge in meat consumption, idiosyncratic regional droughts and fires, speculative bubbles, a new 'financialization' of grain markets, the slowdown of global agricultural research spending, jumps in costs of energy, and more. Several observers have claimed to identify a 'perfect storm' in the grain markets in 2007/2008, a confluence of some of the factors listed above. In fact, the price jumps since 2005 are best explained by the new policies causing a sustained surge in demand for biofuels. The rises in food prices since 2004 have generated huge wealth transfers to global landholders, agricultural input suppliers, and biofuels producers. The losers have been net consumers of food, including large numbers of the world's poorest peoples. The cause of this large global redistribution was no perfect storm. Far from being a natural catastrophe, it was the result of new policies to allow and require increased use of grain and oilseed for production of biofuels. Leading this trend were the wealthy countries, initially misinformed about the true global environmental and distributional implications. [ABSTRACT FROM AUTHOR]

The mandating of increased use of biofuels in transportation fuel in the US initially appeared to offer considerable benefits for developing countries via production and export of sugar cane-based ethanol. This was particularly the case after the contribution of corn-based ethanol was capped at approximately current production levels in the wake of the food price crisis starting in 2007. Closer examination of the complex US biofuels mandate, however, suggests that market access opportunities for developing countries will be much smaller than originally hoped. Current inconsistencies in US biofuels policy increase the riskiness of any developing country investments in the production of biofuels crops and co-requisite infrastructure. As a result, there appears to be little interest in investment in trade-related ethanol activities in developing countries. [ABSTRACT FROM AUTHOR]

A concise and up-to-date review has been undertaken to summarize consistent or diverging agronomic points of view on dedicated energy crops for advanced biofuels in the USA and the EU-27. The main purpose of this review is to discuss those crops where many agronomic constraints have been resolved, bringing them closer to large-scale production and commercialization. Where possible, examples of crop management practices that would enhance sustainability and energy yields are provided. The most promising crops and agronomic strategies for their production in the EU-27 and the USA are discussed. We also provide discussion of what the theoretically ideal characteristics of advanced biofuel crops might be. On both continents, understanding of management practices for switchgrass ( Panicum virgatum L.) and miscanthus ( Miscanthus x giganteus) as energy crops appears to be at an advanced stage. Two other widely considered energy crop candidates - sorghum ( Sorghum bicolor (L.) Moench) and reed canary grass ( Phalaris arundinacea L.) - have production and management guidelines that were developed for forage uses, but can be easily applied to biomass feedstock production. Giant reed ( Arundo donax L.) has been developed as a bioenergy crop mainly in Europe. In the USA, giant reed is considered a noxious weed in many states, and its planting is prohibited. Establishing crop management practices that will be successful at a large scale and for the long term will help attract growers and investors to produce advanced biofuels, i.e. second-generation biofuels, which can help reduce our dependence on fossil energy sources. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The emergence of concerns about 'peak oil,' the fallout from the Iraq War in terms of renewed calls for 'energy security,' and the development of new technology to gain access to fossil fuels and gas long off-limits because of economic and environmental concerns has led to a boom of multiple kinds of energy development in and around rural communities in the United States. This article uses the lens of treadmill-of-production and growth-machine literature to understand these developments in south central Illinois, an area with rich farmland and a history of underground coal extraction. While this analysis finds the expected support from community elites for renewed coal extraction, despite health and environmental risks, we find that the farm community, concerned about damage to land critical for producing corn and beans, profitable at historical levels in part because of the biofuel boom, formed a strong opposition movement. In short, we find evidence of colliding treadmills of energy production. The findings have implications for the analysis of rural energy production in the United States and beyond. [ABSTRACT FROM AUTHOR]

The article discusses research on the use of napiergrass, also known as elephantgrass, as a high-yielding perennial biomass crop in the U.S. as of 2013. Topics include the study of napiergrass as a feedstock for the U.S. bioenergy industry, the fertilization of napiergrass with poultry litter and inorganic fertilizer, and nitrogen supplementation for biomass crop production.

We present a life cycle assessment of synthetic paraffinic kerosene produced from Jatropha curcas. The feedstock is grown in an intercropping arrangement with pasture grasses so that Jatropha is coproduced with cattle. Additional innovations are introduced including hybrid seeds, detoxification of jatropha seedcake, and cogeneration. Two fuel pathways are examined including a newly developed catalytic decarboxylation process. Sensitivities are examined including higher planting density at the expense of cattle production as well as 50% lower yields. Intercropping with pasture and detoxifying seedcake yield coproducts that are expected to relieve pressure on Brazil's forests and indirectly reduce environmental impacts of biofuel production. Other innovations also reduce impacts. Results of the baseline assessment indicate that innovations would reduce impacts relative to the fossil fuel reference scenario in most categories including 62-75% reduction in greenhouse gas emissions, 64-82% reduction in release of ozone depleting chemicals, 33-52% reduction in smog-forming pollutants, 6-25% reduction in acidification, and 60-72% reduction in use of nonrenewable energy. System expansion, which explicitly accounts for avoided deforestation, results in larger improvements. Results are robust across allocation methodologies, improve with higher planting density, and persist if yield is reduced by half. [ABSTRACT FROM AUTHOR]

Increased production of bioenergy crops in North America is projected to exacerbate already heavy demands upon existing agricultural landscapes with potential to impact biodiversity negatively. Grassland specialist birds are an imperilled avifauna for which perennial-based, next-generation agroenergy feedstocks may provide suitable habitat. We take a multi-scaled spatial approach to evaluate the ability of two candidate second-generation agroenergy feedstocks (switchgrass, Panicum virgatum, and mixed grass-forb plantings) to act as spring migratory stopover habitat for birds. In total, we detected 35 bird species in mixed grass-forb plantings and switchgrass plantings, including grassland specialists and species of state and national conservation concern (e.g., Henslow's Sparrow, Ammodramus henslowii). Some evidence indicated that patches with higher arthropod food availability attracted a greater diversity of migrant bird species, but species richness, total bird abundance, and the abundance of grassland specialist species were similar in fields planted with either feedstock. Species richness per unit area (species density) was relatively higher in switchgrass fields. The percent land cover of forest in landscapes surrounding study fields was negatively associated with bird species richness and species density. Habitat patch size and within-patch vegetation structure were unimportant in predicting the diversity or abundance of spring en route bird assemblages. Our results demonstrate that both switchgrass and mixed grass-forb plantings can attract diverse assemblages of migrant birds. As such, industrialized production of these feedstocks as agroenergy crops has the potential to provide a source of en route habitat for birds, particularly where fields are located in relatively unforested landscapes. Because industrialization of cellulosic biomass production will favor as yet unknown harvest and management regimes, predicting the ultimate value of perennial-based biomass plantings for spring migrants remains difficult. [ABSTRACT FROM AUTHOR]

In the United States, only species listed on state or federal noxious weed lists are regulated. According to our analysis, these regulatory lists poorly represent invasive plants in unmanaged (i.e., nonagricultural) systems. To improve the representation of invasive plants on state regulatory lists, we recommend allocating listing authority to invasive species councils and provide guidance for the science-based reform of noxious weed lists. We also recommend commercial best practices to test for invasiveness prior to intentional introduction of new plant products. Finally, we introduce a negligence liability scheme to discourage the introduction of potential invaders. If adopted, our recommendations could benefit nonagricultural ecosystems and could have positive consequences for bioenergy producers and others in plant industry, who are under scrutiny for promoting potentially invasive species as energy crops. As the bioenergy industry gains momentum, a revised regulatory regime may alleviate the concerns regarding one potential negative consequence of novel plant introduction. [ABSTRACT FROM AUTHOR]

The expanding production of bioenergy crops may impact regional air quality through the production of volatile organic compounds such as isoprene. To investigate the effects of isoprene-emitting crops on air quality, specifically ozone (O3) and secondary organic aerosol (SOA) formation, we performed a series of model runs using the Weather Research and Forecasting model with Chemistry (WRF/Chem) coupled with the Model of Emissions of Gases and Aerosols from Nature (MEGAN) simulating a proposed cropland conversion to the giant cane Arundo donax for biomass production. Cultivation of A. donax in the relatively clean air of northeastern Oregon resulted in an average increase in 8 h O3 levels of 0.52 ppb, while SOA was largely unaffected (<+0.01 μg m-3). Conversions in U.S. regions with reduced air quality (eastern Texas and northern Illinois) resulted in average 8 h O3 increases of 2.46 and 3.97 ppb, respectively, with daily increases up to 15 ppb in the Illinois case, and daytime SOA increases up to 0.57 μg m-3. While cultivation of isoprene-emitting bioenergy crops may be appropriate at some scales and in some regions, other areas may experience increased O3 and SOA, highlighting the need to consider isoprene emissions when evaluating potential regional impacts of bioenergy crop production. [ABSTRACT FROM AUTHOR]

Abstract: Power based on biomass, in particular biogas, is increasing, with a concomitant increase in the need for energy crop production. The objective of this study was to determine the profitability of biogas substrate production on a marginal site in southwestern Germany. The effects of crop rotation and nitrogen fertilization level were evaluated in a three-year filed experiment. Production costs for supply of biogas substrates and sales of produced electricity were assessed using five crop rotations (CR1: annual monoculture maize; CR2: perennial monoculture perennial ryegrass; CR3: perennial monoculture Jerusalem artichoke; CR4: three-course crop rotation of sorghum – winter triticale – clover grass; CR5: four-course crop rotation of catch crop – maize – winter wheat – winter triticale) and three nitrogen fertilization levels (zero, middle and high levels of nitrogen). The variables were production costs, dry matter yield, substrate costs, energy output, biomass energy supply price, biomass energy sales price and sale/supply ratio. Production costs increased in the order CR4 (1252 € ha−1 a−1) < CR2 (1256 € ha−1 a−1) < CR5 (1404 € ha−1 a−1) < CR3 (1462 € ha−1 a−1) < CR1 (1649 € ha−1 a−1) due to differing mechanical cultivation needs. Dry matter yields ranged from 10.8 t ha−1 a−1 (CR3) to 4.0 t ha−1 a−1 (CR2) and showed significantly higher yields with increasing fertilization levels. Accounting for all variables, the lowest biomass energy supply price was achieved with CR3 (6.6 ct kWh−1), and increased in the order CR1 < CR5 < CR4 < CR2 (12.4 ct kWh−1). It was determined that only CR3 and CR1 were effective for the production of biogas substrates on marginal sites. The biogas substrate costs of the remaining crop rotations were not compensated for by the sale of electricity. [Copyright &y& Elsevier]

Abstract: Lignin has been recognized for its negative impact on forage digestibility, tree pulping properties, and cellulosic biofuel production, although it is the major structural component of the secondarily thickened cell walls of vascular plants. Earlier studies have demonstrated that lignin modification improves forage digestibility and poplar pulping properties. To determine whether lignin modification has beneficial effect on saccharification of lignocellulosic biomass, we pretreated and then enzymatically hydrolyzed the mature wood from transgenic poplar plants that expressed the antisense transgenes of monolignol biosynthesis genes 4-coumarate: CoA ligase (4CL) or caffeoyl CoA 3-O-methyltransferase (CCoAOMT). Firstly, a long-term field trial was set up for the transgenic plants. Over five years, the reduced trend of lignin content remained stable in all transgenic lines. And a total lignin reduction of up to 10% did not alter the growth rate or biomass yield of the transgenic poplars. In the mature wood, suppression of CCoAOMT increased saccharification potential, but 4CL down-regulation had no significantly positive effect on saccharification. Sugar yield were negatively correlated with soluble lignin content of dried, extractive-free stem biomass. These results imply that lignin modification can facilitate the process of saccharification for biofuel production in tree crops. [Copyright &y& Elsevier]

Abstract: Pennycress is currently being developed as an oilseed crop for biofuel production. Pennycress seeds harvested from a field near Peoria, Illinois, provided our first opportunity to conduct an oil extraction study on a pilot scale. The goals of this study were to determine the effects of seed moisture and cooking on the pressing characteristics of pennycress seeds and to evaluate the quality of the oils extracted. Pennycress seeds (60kg) with 9.5 and 16% moisture contents (MC) were cooked and dried (82–104°C) using a steam-heated 3-deck laboratory seed cooker. The residence times were varied to produce cooked seeds with MCs ranging from 1.0 to 13.0%. The cooked seeds were pressed immediately using a heavy duty laboratory screw press. Pressing rate, press load, and residual oil in the press cakes were determined. The oils extracted were analyzed for solids content (foots), free fatty acid (FFA) content, color, and phosphorus (P), calcium (Ca), magnesium (Mg), and sulfur (S) contents. Pressing uncooked pennycress seeds with 9.5% MC produced press cake with 10.7% oil (db), extracting 75.1% of the oil in the seed. Cooking and drying the seeds between 3 and 4% MC provided the highest oil recovery at 86.3 and 88.0% for seeds with 9.5 and 16% starting seed MC, respectively. The pressing rates and press loads at these MCs were similar. Compared to the oil from uncooked seeds, the oils from cooked seeds had higher foots (1.55–1.73% vs. 0.52%), slightly higher FFA contents (0.40–0.46% vs. 0.30%), and slightly higher red values in AOCS RY color scale (4.1R–6.2R vs. 2.4R). Cooking increased the phosphatide content but the amount was still comparable to degummed oils. The sulfur levels in the expelled oil were higher than the amounts found in rapeseed oil and varied considerably depending on the seed moisture and the extent of cooking employed. [Copyright &y& Elsevier]

United States (U.S.) energy policy includes an expectation that bioenergy will be a substantial future energy source. In particular, the Energy Independence and Security Act of 2007 (EISA) aims to increase annual U.S. biofuel (secondary bioenergy) production by more than 3-fold, from 40 to 136 billion liters ethanol, which implies an even larger increase in biomass demand (primary energy), from roughly 2.9 to 7.4 EJ yr-1. However, our understanding of many of the factors used to establish such energy targets is far from complete, introducing significgant uncertainty into the feasibility of current estimates of bioenergy potential. Here, we utilized satellite-derived net primary productivity (NPP) data-measured for every 1 km² of the 7.2 million km² of vegetated land in the conterminous U.S.-to estimate primary bioenergy potential (PBP). Our results indicate that PBP of the conterminous U.S. ranges from roughly 5.9 to 22.2 EJ yr-1, depending on land use. The low end of this range represents the potential when harvesting residues only, while the high end would require an annual biomass harvest over an area more than three times current U.S. agricultural extent. While EISA energy targets are theoretically achievable, we show that meeting these targets utilizing current technology would require either an 80% displacement of current crop harvest or the conversion of 60% of rangeland productivity. Accordingly, realistically constrained estimates of bioenergy potential are critical for effective incorporation of bioenergy into the national energy portfolio. [ABSTRACT FROM AUTHOR]

In the past, deforestation, mainly driven by the conversion of natural forests to agricultural land, contributed up to one-fifth of global human induced carbon dioxide (CO2) emissions. Substitution of bioenergy for fossil energy is an intensely discussed option for mitigating CO2 emissions. This paper, by applying a global land-use model and a global energy–economy–climate model, explores how demand for cellulosic bioenergy crops will add an additional pressure on the land system in the future. In accordance with other studies, we find that CO2 emissions from land use change due to energy crop production will be an important factor in the GHG balance of bioenergy if natural forests will not be protected. But restricting land availability for biomass plantations by conserving natural forests requires additional efforts in the agricultural sector: First, our simulation results indicate that significant additional crop yield increases will be needed due to the combination of forest conservation and the cultivation of dedicated bioenergy crops. Secondly, our simulation results show that forest conservation in combination with increasing demand for dedicated bioenergy crops will lead to higher agricultural production costs of approximately 20%. [Copyright &y& Elsevier]

This paper looks at the prospects of the agricultural production of biomass to be used for energy purposes. The author presents the benefits of crop cultivation for energy purposes, and assesses the risks associated with environmental degradation as well as the risks of the energy crops competing with crops for food. Moreover, this paper discusses the necessity to respect the principles of sustainable development and includes information about the prospects for higher generation biofuels (which enable more efficient use of biomass). [ABSTRACT FROM AUTHOR]

Using marginal agricultural lands to grow energy crops for biofuel feedstocks is a promising option to meet the biofuel needs in populous China without causing further food shortages or environmental problems. Here we quantify the effects of growing switchgrass and Miscanthus on Chinese marginal agricultural lands on biomass production and carbon emissions with a global-scale biogeochemical model. We find that the national net primary production (NPP) of these two biofuel crops are 622 and 1546 g C m-2 yr-1, respectively, whereas the NPP of food crops is about 600 g C m-2 yr-1 in China. The net carbon sink over the 47 Mha of marginal agricultural lands across China is 2.1 Tg C yr-1 for switchgrass and 5.0 Tg C yr-1 for Miscanthus. Soil organic carbon is estimated to be 10 kg C m-2 in both biofuel ecosystems, which is equal to the soil carbon levels of grasslands in China. In order to reach the goal of 12.5 billion liters of bioethanol in 2020 using crop biomass as biofuel feedstocks, 7.9-8.0 Mha corn grain, 4.3-6.1 Mha switchgrass, or 1.4-2.0 Mha Miscanthus will be needed. Miscanthus has tremendous potential to meet future biofuel needs, and to benefit CO2 mitigation in China. [ABSTRACT FROM AUTHOR]

Abstract: Biomass from cellulosic bioenergy crops is seen as a substantial part of future energy systems, especially if climate policy aims at stabilizing CO2 concentration at low levels. However, among other concerns of sustainability, the large-scale use of bioenergy is controversial because it is hypothesized to increase the competition for land and therefore raise N2O emissions from agricultural soils due to intensification. We apply a global land-use model that is suited to assess agricultural non-CO2 GHG emissions. First, we describe how fertilization of cellulosic bioenergy crops and associated N2O emissions are implemented in the land-use model and how future bioenergy demand is derived by an energy-economy-climate model. We then assess regional N2O emissions from the soil due to large-scale bioenergy application, the expansion of cropland and the importance of technological change for dedicated bioenergy crops. Finally, we compare simulated N2O emissions from the agricultural sector with CO2 emissions from the energy sector to investigate the real contribution of bioenergy for low stabilization scenarios. As a result, we find that N2O emissions due to energy crop production are a minor factor. Nevertheless, these co-emissions can be significant for the option of removing CO2 from the atmosphere (by combining bioenergy use with carbon capture and storage (CCS) options) possibly needed at the end of the century for climate mitigation. Furthermore, our assessment shows that bioenergy crops will occupy large shares of available cropland and will require high rates of technological change at additional costs. [Copyright &y& Elsevier]

The removal of corn stover or production of herbaceous crops such as switchgrass (Panicum virgatum) or big bluestem (Andropogon gerardii) as feedstocks for bioenergy purposes has been shown to have significant benefits from an energy and climate change perspective. There is potential, however, to adversely impact water and soil quality, especially in the United States Corn Belt where stover removal predominantly occurs and possibly in other areas with herbaceous energy crops depending upon a number of geo-climatic and economic factors. The overall goal of this research was to provide a thorough and mechanistic understanding of the relationship between stover and herbaceous crop production management practices and resulting range of impacts on soil and water quality, with a focus on eastern Iowa, USA. Comparisons of the production of herbaceous bioenergy crops to continuous corn (Zea mays L.) and corn-soybean (Glycine max L.) rotations on five different soils representative of the region were performed. Indices for total nutrient (nitrogen and phosphorus) loss to surface water and groundwater, total soil loss due to water and wind erosion, and cumulative soil carbon loss were derived to assess long-term sustainability. The Agricultural Policy/Environmental eXtender (APEX) agroecosystem model was used to quantify the sustainability indices and to generate sufficient data to provide a greater understanding of variables that affect water and soil quality than previously possible. The results clearly show the superiority of herbaceous crop production from a soil and water quality perspective. They also show, however, that compared to traditional cropping systems (e.g., corn-soybean rotations with conventional tillage), soil and water quality degradation can be reduced under certain conditions at the same time stover is removed. [Copyright &y& Elsevier]

Abstract: Bioenergy and energy crops are an important part of the UK’s renewable energy strategy to reach its greenhouse gas reduction target of 80% by 2050. Ensuring the sustainability of biomass feedstocks requires a greater understanding of all aspects of energy crop production, their ecological impacts and yields. This work compares the life-cycle environmental impact of natural gas and biomass from two energy crop systems grown under typical UK agronomic practice. As reported in previous studies the energy crops provide significant reductions in global warming potential (GWP) compared to natural gas. Compared to no fertiliser application, applying inorganic fertiliser increases the GWP by 2% and applying sewage sludge increases the GWP by a lesser extent. In terms of an equivalent GWP savings per unit area of land, the emissions associated with fertiliser production and application can be offset by a yield increase of <0.2 t/ha. However, very large increases in eutrophication and acidification levels are incurred compared to the natural gas reference case when applying either fertiliser. For sewage sludge the impact of varying the allocation factor between the function of wastewater treatment and that of crop growth is also illustrated. [Copyright &y& Elsevier]

Abstract: Today’s bioenergy systems are very different in cultivation, conservation, conversion of the biomass as well as in the form of the final energy. The assessment of bioenergy systems concerning environmental impacts is increasingly up for discussion. Future challenges will be the development of procedures which reconcile high-yielding and efficient approaches with environment friendly production. Against this background the system of Integrated Generation of Solid Fuel and Biogas from Biomass (IFBB) was suggested to increase net energy yields over a wide range of energy crops in order to obtain a higher biodiversity in energy crop cultivation. In the IFBB procedure the ensiled biomass is separated into a liquid phase for biogas production and into a solid fraction for combustion. This work is aimed at the assessment of the IFBB system in comparison to whole crop digestion (WCD). The assessment is based on crop production in a double-cropping system where winter rye and maize are grown subsequently within one growing season. The main parameters investigated are the efficiency of the whole process, primary energy and greenhouse gas savings as well as potentials of acidification and eutrophication according to principles of Life Cycle Assessment. The calculation of energy efficiency shows a superiority of the IFBB system due to a mainly thermal use of the biomass. Savings of fossil primary energy average at a similar level, whereas greenhouse gas savings are slightly higher for WCD. Investigations on acidification and eutrophication show that both bioenergy systems caused higher emissions compared to the fossil-based reference technique. [ABSTRACT FROM AUTHOR]

Regulatory restrictions have increased in recent years on organisms produced using recombinant DNA and asexual gene transfer, a process commonly called genetic engineering or genetic modification. Regulatory agencies have raised special concerns and required additional scrutiny for perennial grasses and woody plants of interest for biofuels; these plants have incomplete domestication, invasive capabilities, and the ability to mate with wild or feral relatives. Regulations on these plants require extremely stringent containment through all phases of research and development, regardless of the source of the gene, the novelty of the trait, or the plants' anticipated economic or environmental benefits. We discuss the extent to which these requirements conflict with the realities of practical crop breeding, and prevent meaningful agronomic and environmental studies, thus hampering--and in most cases, precluding--the use of recombinant DNA breeding methods for perennial crop improvement. We propose regulatory reforms to better balance benefit and risk and remove unnecessary barriers to agronomic evaluations and environmental studies. [ABSTRACT FROM AUTHOR]

This article considers the global expansion of agrofuels feedstock production from a political economy perspective. It considers and dismisses the environmental and pro-poor developmental justifications attached to agrofuels. To local populations and direct producers, the specific destination of the crop as fuel, food, cosmetics or other final uses in faraway places is probably of less interest than the forms of (direct or indirect) appropriation of their land and the forms of their insertion or exclusion as producers in global commodity chains. Global demand for both agrofuels and food is stimulating new forms (or the resurgence of old forms) of corporate land grabbing and expropriation, and of incorporation of smallholders in contracted production. Drawing both on recent studies on agrofuels expansion and on the political economy literature on agrarian transition and capitalism in agriculture, this article raises the question whether 'agrofuels capitalism' is in any way essentially different from other forms of capitalist agrarian monocrop production, and in turn whether the agrarian transitions involved require new tools of analysis. [ABSTRACT FROM AUTHOR]

New alliances between Brazil and the US for ethanol production, transport, and trade are revitalising and expanding the centuries-old sugarcane plantation system in the Americas. In this paper I adopt the concept of global assemblages, building on the work of Aihwa Ong, Stephen Collier, and Saskia Sassen, to draw the contours of an 'ethanol assemblage', which includes states, corporations, growers, technologies, urban consumers, and rural communities and landscapes. Though important to conceptualise agrofuels as a global phenomenon, it is also necessary to recognise the distinct regional patterns that cohere around various aspects of this polymorphous industry. Therefore, I focus on alliances around sugarcane ethanol, paying particular attention to the role of Miami as a global city serving as a gateway to information, investment, and commodities for the public/private and national/transnational entities that are engaged in the hemispheric project of ethanol promotion, production and distribution. [ABSTRACT FROM AUTHOR]

Many studies have compared corn-based ethanol to cellulosic ethanol on a per unit basis and have generally concluded that cellulosic ethanol will result in fewer environmental consequences, including nitrate (NO3-) output. This study takes a system-wide approach in considering the NO3- output and the relative areal extent of hypoxia in the Northern Gulf of Mexico (NGOM) due to the introduction of additional crops for biofuel production. We stochastically estimate NO3- loading to the NGOM and use these results to approximate the areal extent of hypoxia for scenarios that meet the Energy Independence and Security Act of 2007's biofuel goals for 2015 and 2022. Crops for ethanol include corn, corn stover, and switchgrass; all biodiesel is assumed to be from soybeans. Our results indicate that moving from corn to cellulosics for ethanol production may result in a 20-percent decrease (based on mean values) in NO3- output from the Mississippi and Atchafalaya River Basin (MARB). This decrease will not meet the EPA target for hypoxic zone reduction. An aggressive nutrient management strategy will be needed to reach the 5000 km² areal extent of hypoxia in the NGOM goal set forth by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force even in the absence of biofuels, given current production to meet food, feed, and other industrial needs. [ABSTRACT FROM AUTHOR]

Recent increases in the price of oil have generated much interest in biofuel development but the social and environmental impacts of large scale adoption of biofuels at both regional and national scales remain understudied, especially in developing economies. Although the recent swings in prices for oil may slow down these surges in supply and demand, production of biofuels from food remain profitable above $50/barrel making the biofuel market viable. Here we use municipality-level data for the state of São Paulo in Brazil to explore the effects of fires associated with sugarcane cultivation on respiratory health of elderly and children. We examined the effects of fires occurring in the same year in which respiratory cases were reported as well as chronic effects associated with long-term cultivation of sugarcane. Across the state, respiratory morbidity attributable to fires accounted for 113 elderly and 317 child cases, approximately 1.8% of total cases in each group. Although no chronic effects of fire were detected for the elderly group, an additional 650 child cases can be ascribed to the long-term cultivation of sugar cane increasing to 5.4% the percent of children cases that can be attributed to fire. For municipalities with greater than 50% of the land in sugarcane the percentage increased to 15% and 12%, respectively, for elderly and children. An additional 209 child cases could also be attributed to past exposure to fires associated with sugarcane, suggesting that in total 38% of children respiratory cases could be attributed to current or chronic exposure to fires in these municipalities. The harmful effects of cane-associated fires on health are not only a burden for the public health system but also for household economies. This type of information should be incorporated into land use decisions and discussions of biofuel sustainability. [Copyright &y& Elsevier]

The basic aspects of liquid biofuels (biodiesel and fuel ethanol) production are discussed, including advantages and disadvantages, raw materials, technologies, prospects of development and challenges for their successful implementation in the national and international context. The article also provides a brief analysis of the biofuels impact on the environment as the main contribution to sustainable mobility. This work additionally describes a strategy designed together with FAO to assess the impact of biofuels on food security. [ABSTRACT FROM AUTHOR]

The article discusses the environmental impact that water consumption and agrochemical use could have, during the production of biofuels such as ethanol, on the availability and quality of the resource. Meeting the global challenge of providing inexpensive and clean water could be intensified by the increasing demand for biofuels or transportation biofuel needs including the need for large quantities of water to grow the fuel crops and water pollution due to agricultural drainage which contain fertilizers, pesticides, and sediment. Topics include how these potential drawbacks are balanced by the potential of biofuels to ease dependence on foreign oil, improve trade balance(s), and mitigate air pollution through the reduction of fossil carbon emissions.

It is becoming increasingly vital to improve the yield of seed crops to feed an expanding population and, more recently, for biofuel production. One strategy to increase the yield is to increase the seed size, provided that there is not a concomitant decrease in seed number. In a previous study, we described a mutant in the AUXIN RESPONSE FACTOR 2 ( ARF2) gene which produced extra cells in the seed coat and, subsequently, enlarged seeds. However, arf2 mutant plants also show severely reduced self-fertility caused, in part, by over-elongated sepals that prevent flower opening. As a low seed set increases individual seed size, a meaningful comparison of the yield in arf2 and wild-type plants could not be conducted. In this study, we show that targeted expression of wild-type ARF2 in the sepals and petals of arf2-9 mutant flowers restores flower opening and dramatically increases seed set. The restored plants retain both enlarged integuments and increased seed size, reinforcing previous evidence that arf2 mutations increase seed weight through their effect on integuments and not only via reduced fertility. We also show that the measurement of the harvest index in Arabidopsis is useful in assessing the impact of introduced traits on the yield. [ABSTRACT FROM AUTHOR]

Greenhouse gas abatement policies will increase the demand for renewable sources of energy, including bioenergy. In combination with a global growing demand for food, this could lead to a food-fuel competition for bio-productive land. Proponents of bioenergy have suggested that energy crop plantations may be established on less productive land as a way of avoiding this potential food-fuel competition. However, many of these suggestions have been made without any underlying economic analysis. In this paper, we develop a long-term economic optimization model (LUCEA) of the U.S. agricultural and energy system to analyze this possible competition for land and to examine the link between carbon prices, the energy system dynamics and the effect of the land competition on food prices. Our results indicate that bioenergy plantations will be competitive on cropland already at carbon taxes about US $20/ton C. As the carbon tax increases, food prices more than double compared to the reference scenario in which there is no climate policy. Further, bioenergy plantations appropriate significant areas of both cropland and grazing land. In model runs where we have limited the amount of grazing land that can be used for bioenergy to what many analysts consider the upper limit, most of the bioenergy plantations are established on cropland. Under the assumption that more grazing land can be used, large areas of bioenergy plantations are established on grazing land, despite the fact that yields are assumed to be much lower (less than half) than on crop land. It should be noted that this allocation on grazing land takes place as a result of a competition between food and bioenergy production and not because of lack of it. The estimated increase in food prices is largely unaffected by how much grazing land can be used for bioenergy production. [ABSTRACT FROM AUTHOR]

Reports on the issues on the extension of biomass co-firing for technical changes of renewable obligations in Great Britain. Recommendation from ILEX Consulting on the development of energy crops; Benefits of co-firing; Impact of of biomass co-firing on the energy crop industry.