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A variety of forces aligned at the turn of the last century to make ethyl alcohol - what is today known as ethanol - inefficient and uneconomical as a fuel alternative. Rather than a case of inevitable technological unfolding, the transition from King Coal to Big Oil was a sociologically contingent event. As a controversy study, this paper seeks to avoid the reductionist tendencies of past historical analyses of fuel. The author also seeks to redress a fundamental gap within the STS literature on the subject of automobile/fuel socio-technical systems, where the story of ethyl alcohol remains conspicuously absent. Among studies that examine how/why the automobile became locked in, little is said about ethyl alcohol, even though, as this paper details, it remained part of the fuel landscape well into the 20th century. The paper begins with an overview of the landscape developments of fuel during the later decades of the 19th century. Attention then turns to examining the various factors that went into shaping the automobile/fuel socio-technical system within the US during the first half of the 20th century. [ABSTRACT FROM AUTHOR]

Forests of the Midwestern United States are an important source of fiber for the wood and paper products industries. Scientists, land managers, and policy makers are interested in using woody biomass and/or harvest residue for biofuel feedstocks. However, the effects of increased biomass removal for biofuel production on forest production and forest system carbon balance remain uncertain. We modeled the carbon (C) cycle of the forest system by dividing it into two distinct components: (1) biological (net ecosystem production, net primary production, autotrophic and heterotrophic respiration, vegetation, and soil C content) and (2) industrial (harvest operations and transportation, production, use, and disposal of major wood products including biofuel and associated C emissions). We modeled available woody biomass feedstock and whole-system carbon balance of 220 000 km2 of temperate forests in the Upper Midwest, USA by coupling an ecosystem process model to a collection of greenhouse gas life-cycle inventory models and simulating seven forest harvest scenarios in the biological ecosystem and three biofuel production scenarios in the industrial system for 50 years. The forest system was a carbon sink (118 g C m−2 yr−1) under current management practices and forest product production rates. However, the system became a C source when harvest area was doubled and biofuel production replaced traditional forest products. Total carbon stores in the vegetation and soil increased by 5-10% under low-intensity management scenarios and current management, but decreased up to 3% under high-intensity harvest regimes. Increasing harvest residue removal during harvest had more modest effects on forest system C balance and total biomass removal than increasing the rate of clear-cut harvests or area harvested. Net forest system C balance was significantly, and negatively correlated ( R2 = 0.67) with biomass harvested, illustrating the trade-offs between increased C uptake by forests and utilization of woody biomass for biofuel feedstock. [ABSTRACT FROM AUTHOR]

Rapid growth of biofuel production in the United States and Brazil over the past decade has increased interest in replicating this success in other nations of the Pan American region. However, the continued use of food-based feedstock such as maize is widely seen as unsustainable and is in some cases linked to deforestation and increased greenhouse gas emissions, raising further doubts about long-term sustainability. As a result, many nations are exploring the production and use of cellulosic feedstock, though progress has been extremely slow. In this paper, we will review the North-South axis of biofuel production in the Pan American region and its linkage with the agricultural sectors in five countries. Focus will be given to biofuel policy goals, their results to date, and consideration of sustainability criteria and certification of producers. Policy goals, results, and sustainability will be highlighted for the main biofuel policies that have been enacted at the national level. Geographic focus will be given to the two largest producers-the United States and Brazil; two smaller emerging producers-Argentina and Canada; and one stalled program-Mexico. However, several additional countries in the region are either producing or planning to produce biofuels. We will also review alternative international governance schemes for biofuel sustainability that have been recently developed, and whether the biofuel programs are being managed to achieve improved environmental quality and sustainable development. [ABSTRACT FROM AUTHOR]

Pioneer cellulosic biorefineries across the United States rely on a conventional feedstock supply system based on one-year contracts with local growers, who harvest, locally store, and deliver feedstock in low-density format to the conversion facility. While the conventional system is designed for high biomass yield areas, pilot scale operations have experienced feedstock supply shortages and price volatilities due to reduced harvests and competition from other industries. Regional supply dependency and the inability to actively manage feedstock stability and quality, provide operational risks to the biorefinery, which translate into higher investment risk. The advanced feedstock supply system based on a network of depots can mitigate many of these risks and enable wider supply system benefits. This paper compares the two concepts from a system-level perspective beyond mere logistic costs. It shows that while processing operations at the depot increase feedstock supply costs initially, they enable wider system benefits including supply risk reduction (leading to lower interest rates on loans), industry scale-up, conversion yield improvements, and reduced handling equipment and storage costs at the biorefinery. When translating these benefits into cost reductions per liter of gasoline equivalent (LGE), we find that total cost reductions between -$0.46 to -$0.21 per LGE for biochemical and -$0.32 to -$0.12 per LGE for thermochemical conversion pathways are possible. Naturally, these system level benefits will differ between individual actors along the feedstock supply chain. Further research is required with respect to depot sizing, location, and ownership structures. [ABSTRACT FROM AUTHOR]

Abstract: During the last decade, countries around the world - especially the U.S., Brazil, and many in Europe - have worked to accelerate the commercialization of a biofuel industry. As pilot plant studies for the second-generation biofuel (e.g., cellulosic biofuel) currently seek to determine the most viable feedstocks and processing technologies, it is an opportune time to formulate operations research (OR) models of the biofuel supply chain (SC) so they might be used to implement the technologies that prove to be most promising. This paper provides a literature review of research on the biofuel SC. It classifies prior research according to decision time frame (i.e., strategic, tactical, operational, and integrated) as well as level in the supply chain (i.e., upstream, midstream, and downstream). In addition, it reviews related research on agri-products, which have some commonalities relative to harvesting and perishability; petroleum-based fuels, which have some commonalities related to distribution (some biofuels can be mixed with gasoline but others cannot); and generic supply chains, which provide some applicable modeling structures. Finally, this paper emphasizes unique needs to support decisions that integrate the farm with commercial levels (e.g., storage, pre-processing, refining, and distribution) and identifies fertile avenues for future research on the biofuel supply chain. OR models are needed to help assure the economic viability of the biofuel industry. They can be used by growers, processors, and distributors to design and manage an integrated system and by government to inform policies needed to stimulate the growth of the industry and, perhaps, subsidize it. [Copyright &y& Elsevier]

Copyright of CES Medicina Veterinaria & Zootecnica is the property of Universidad CES and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Renewable energy is an option for many countries simultaneously seeking to reduce dependence on imported petroleum and to reduce greenhouse gas (GHG) emissions that contribute to climate change. Forestry can play a role in environmental policies, such as renewable portfolio standards for bioelectricity, renewable fuel standards for biofuels, and forest carbon sequestration. This paper models interactions and interdependencies between bioelectricity and biofuel production, particularly from forest biomass. A global computable general equilibrium (CGE) model is used to measure the economic effects of bioenergy production from forest products, forest residues, and dedicated energy crops. The land use and emissions impacts on the global economy of revenue-neutral GHG mitigation policies are evaluated. Results show that mandated bioenergy production can substantially reduce carbon dioxide (CO2) emissions, especially through fossil fuel substitution in the electricity sector. Although emissions reductions from bioenergy production in the transportation fuel sector are less dramatic than those in the electricity sector, biofuels also have lower emissions rates than petroleum-based transportation fuels. [Copyright &y& Elsevier]

Abstract: To meet rising energy demands in a sustainable manner, the United States Renewable Fuel Standard 2 (RFS2) mandates the production of 3.78billion L (1billion gallons) of biomass-based biodiesel per year by 2020. Urban marginal lands, herein defined as lots with poor agricultural potential and unfit for residential purposes, can be used to cultivate biodiesel feedstock, which can contribute toward the RFS2. GIS is particularly well suited to identify the amount and location of these urban marginal lands. Biofuel crop production is one way for urban neighborhoods to reclaim vacant, blighted properties and also generate green energy for consumption. Combining soil classification data with urban development data, a GIS framework was developed to determine the amount of urban marginal land available in Pittsburgh, Pennsylvania. This location was chosen because small-scale sunflower crops are already being grown on urban marginal lands for biodiesel production. This paper evaluates two methods for identifying marginal lands for biofuel cultivation. The first is based on NRCS soil classifications derived from previous literature approaches. When compared with the locations of a nonprofit that is actually cultivating marginal lands, the NRCS soil classification method captures less than 35% of the marginal lands being cultivated in Pittsburgh, and 2400ha (6000acres) of marginal land in total that could be used to grow sunflowers for biodiesel production. We modify the NRCS marginal soil classification method to include certain types of urban commercial lands and lands not currently classified as marginal, and create a framework that identifies almost 90% of the marginal lands currently under cultivation in Pittsburgh, with approximately 3500ha (8700 acres) of available marginal lands. Pittsburgh’s marginal lands could be used to produce up to 129,000L (34,100gallons) of sunflower-based biodiesel. This could contribute a maximum of 0.1% to Pennsylvania’s biofuel mandate and 0.003% to the RFS2. While a city’s individual contribution may be incremental on the national scale, multiple cities and regions may be able to contribute to the RFS2. In addition, there is an unquantified social benefit that results from community engagement and revitalization, which is part of the mission of the Pittsburgh nonprofit. [Copyright &y& Elsevier]

We estimate the contributions from biomass burning (summer wildfires, other fires, residential biofuel, and industrial biofuel) to seasonal and annual aerosol concentrations in the United States. Our approach is to use total carbonaceous (TC) and non-soil potassium (ns-K) aerosol mass concentrations for 2001–2004 from the nationwide IMPROVE network of surface sites, together with satellite fire data. We find that summer wildfires largely drive the observed interannual variability of TC aerosol concentrations in the United States. TC/ns-K mass enhancement ratios from fires range from 10 for grassland and shrub fires in the south to 130 for forest fires in the north. The resulting summer wildfire contributions to annual TC aerosol concentrations for 2001–2004 are 0.26μgCm−3 in the west and 0.14μgCm−3 in the east; Canadian fires are a major contributor in the east. Non-summer wildfires and prescribed burns contribute on an annual mean basis 0.27 and 0.31μgCm−3 in the west and the east, highest in the southeast because of prescribed burning. Residential biofuel is a large contributor in the northeast with annual mean concentration of up to 2.2μgCm−3 in Maine. Industrial biofuel (mainly paper and pulp mills) contributes up to 0.3μgCm−3 in the southeast. Total annual mean fine aerosol concentrations from biomass burning average 1.2 and 1.6μgm−3 in the west and east, respectively, contributing about 50% of observed annual mean TC concentrations in both regions and accounting for 30% (west) and 20% (east) of total observed fine aerosol concentrations. Our analysis supports bottom-up source estimates for the contiguous United States of 0.7–0.9TgCyr−1 from open fires (climatological) and 0.4TgCyr−1 from biofuel use. Biomass burning is thus an important contributor to US air quality degradation, which is likely to grow in the future. [Copyright &y& Elsevier]

Switchgrass (Panicum virgatum L.) has been identified as a potential feedstock for cellulosic ethanol production in United States for its high biomass yield and adaptation to marginal lands. Composition of the cell wall plays an important role in bioethanol conversion. A total of 209 pseudo‐F1 testcross progenies obtained from a biparental cross, AP13 × VS16, were grown at three locations from 2008 to 2011. Near‐infrared spectroscopy was used to estimate cell wall composition from biomass harvested at maturity. A linkage map of the pseudo‐F1 testcross was constructed with 8,757 SNPs developed by genotyping‐by‐sequencing. Quantitative trait loci (QTL) analysis was performed on eight lignocellulosic traits, namely, klason lignin, sugar, glucose, xylose, hexose, ethanol, hexosoic ethanol, and cell wall ethanol conversion percentage. A total of 327 QTL were recorded for the eight lignocellulosic traits. We have identified 111 major regions in the switchgrass genome that underlie these lignocellulosic traits. Scanning of the genome sequence for genes flanking the QTL peaks, we identified 45 important genes that are involved in lignin biosynthesis, carbohydrate and sugar metabolism, and other biological and cellular functions. Identification of valuable genes associated with QTL along with pleotropic effects of the significant number of QTL suggests that simultaneous selection and genetic improvement of these traits are possible using marker‐assisted selection. [ABSTRACT FROM AUTHOR]

Expansion of ethanol production in the United States has raised concerns regarding its land-use change effects. However, little is known about the extent to which observed land use change in the United States can be attributed to ethanol plant proximity or is caused by changes in crop prices that may be partly induced by expansion in ethanol production. This study aims to examine the determinants of changes in corn acreage and aggregate crop acreage by simultaneously identifying the effects of establishment of ethanol plants serving as terminal markets for corn and the effects of changes in crop prices in the United States between 2003 and 2014. Our results show that corn acreage and total acreage are fairly inelastic with respect to both changes in ethanol capacity in the vicinity, as well as changes in crop prices. Our estimates of acreage elasticity with respect to corn ethanol production are smaller than those obtained by previous studies that disregard the price effect on crop acreage. We find that, ceteris paribus, the increase in ethanol capacity alone led to a modest 3% increase in corn acreage and less than a 1% increase in total crop acreage by 2012 when compared to 2008. The effect of corn price and aggregate crop price on acreage change from 2008 to 2012 was more than twice larger than that of effective ethanol production capacity over this period; but this price effect was largely reversed by the downturn in crop prices after 2012. This study shows that land-use change is not a static phenomenon and that it is important to examine how it evolves in response to various factors that may change over time. [ABSTRACT FROM AUTHOR]

Copyright of Annals of the American Association of Geographers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Producing biofuel feedstocks on current agricultural land raises questions of a 'food-vs.-fuel' trade-off. The use of current or former Conservation Reserve Program ( CRP) land offers an alternative; yet the volumes of ethanol that could be produced and the potential environmental impacts of such a policy are unclear. Here, we applied the Environmental Policy Integrated Climate model to a US Department of Agriculture database of over 200 000 CRP polygons in Iowa, USA, as a case study. We simulated yields and environmental impacts of growing three cellulosic biofuel feedstocks on CRP land: (i) an Alamo-variety switchgrass ( Panicum virgatum L.); (ii) a generalized mixture of C4 and C3 grasses; (iii) and no-till corn ( Zea mays L.) with residue removal. We simulated yields, soil erosion, and soil carbon (C) and nitrogen (N) stocks and fluxes. We found that although no-till corn with residue removal produced approximately 2.6-4.4 times more ethanol per area compared to switchgrass and the grass mixture, it also led to 3.9-4.5 times more erosion, 4.4-5.2 times more cumulative N loss, and a 10% reduction in total soil carbon as opposed to a 6-11% increase. Switchgrass resulted in the best environmental outcomes even when expressed on a per liter ethanol basis. Our results suggest planting no-till corn with residue removal should only be done on low slope soils to minimize environmental concerns. Overall, this analysis provides additional information to policy makers on the potential outcome and effects of producing biofuel feedstocks on current or former conservation lands. [ABSTRACT FROM AUTHOR]

Impact of climate change on the water resources of the United States exposes the vulnerability of feedstock-specific mandated fuel targets to extreme weather conditions that could become more frequent and intensify in the future. Consequently, a sustainable biofuel policy should consider: (a) how climate change would alter both water supply and demand; and (b) in turn, how related changes in water availability will impact the production of biofuel crops; and (c) the environmental implications of large scale biofuel productions. Understanding the role of biofuels in the water cycle is the key to understanding many of the environmental impacts of biofuels. Therefore, the focus of this study is to model the rarely explored interactions between land use, climate change, water resources and the environment in future biofuel production systems. Results from this study will help explore the impacts of the US biofuel policy and climate change on water and agricultural resources. We used the Soil and Water Assessment Tool (SWAT) to analyze the water quantity and quality consequences of land use and land management related changes in cropping conditions (e.g., more use of marginal lands, greater residue harvest, increased yields), plus management practices due to biofuel crops to meet the Renewable Fuel Standard target on water quality and quantity. [ABSTRACT FROM AUTHOR]

The use of biofuels as a replacement for fossil fuels is growing in the United States and other countries in part because of economic and environmental concerns. One of the technologies for biofuels production is fast pyrolysis; however, to increase manufacturing of fast pyrolysis units, a better understanding of stakeholders' requirements and perspectives is needed. This is a complex decision problem. Due to the diversity of perspectives, each group of stakeholders has their own unique requirements, which in total will determine the right manufacturing approach. Previous studies either investigated optimal sizing from a single viewpoint or have combined a subset of perspectives. This study applies multiple tools to develop a more comprehensive view of stakeholders' perspectives. Individual subject matter experts were asked to review and prioritize a set of requirements that reflected different stakeholders' perspectives, including economic, environmental, technical, social, and legal. The perspectives were then used to analyze multiple fast pyrolysis units to determine which size was the most effective in meeting the perspectives in total. The analysis indicated that the smallest unit, able to process an average of 50 tons per day, is the best alternative when viewed from the economic, technical, social, and legal perspectives. However, when viewed from the environmental perspective, a medium-sized unit, able to process in the range of 200-500 tons per day, is the best alternative. This work provides the basis for further discussions about the individual perspectives, including the economic and environmental perspectives of biofuel production. Potential avenues for further work in assessment of stakeholders' requirements are also noted. [ABSTRACT FROM AUTHOR]

This review discusses research on linkages between biofuels, agriculture, and food security. The literature indicates that biofuel expansion affects land use, puts pressure on food and feed markets, and modestly reduces greenhouse gas emissions. Researchers readily identify these outcomes, as well as the multitude of factors besides biofuels that have driven up food prices in recent years. However, precision in quantifying the extent of the impacts and in attributing effects to various drivers is elusive, resulting in a wide range of estimates. Nevertheless, the central tendency is that a food-versus-fuel trade-off is created through biofuel production from food crops, and the continued expansion of biofuel production increases food commodity prices, reduces the availability of calories, and increases malnourishment in developing countries. Higher food prices particularly reduce the poor's access to food, which has possible long-term, irreversible consequences for health, productivity, and well-being. [ABSTRACT FROM AUTHOR]

Background: Woody biomass is one of the most abundant biomass feedstocks, besides agriculture residuals in the United States. The sustainable harvest residuals and thinnings alone are estimated at about 75 million tons/year. These forest residuals and thinnings could produce the equivalent of 5 billion gallons of lignocellulosic ethanol annually. Softwood biomass is the most recalcitrant biomass in pretreatment before an enzymatic hydrolysis. To utilize the most recalcitrant lignocellulosic materials, an efficient, industrially scalable and cost effective pretreatment method is needed. Results: Obtaining a high yield of sugar from recalcitrant biomass generally requires a high severity of pretreatment with aggressive chemistry, followed by extensive conditioning, and large doses of enzymes. Catchlight Energy's Sugar process, CLE Sugar, uses a low intensity, high throughput variation of bisulfite pulping to pretreat recalcitrant biomass, such as softwood forest residuals. By leveraging well-proven bisulfite technology and the rapid progress of enzyme suppliers, CLE Sugar can achieve a high yield of total biomass carbohydrate conversion to monomeric lignocellulosic sugars. For example, 85.8% of biomass carbohydrates are saccharified for un-debarked Loblolly pine chips (softwood), and 94.0% for debarked maple chips (hardwood). Furan compound formation was 1.29% of biomass feedstock for Loblolly pine and 1.10% for maple. At 17% solids hydrolysis of pretreated softwood, an enzyme dose of 0.075 g Sigma enzyme mixture/g dry pretreated (unwashed) biomass was needed to achieve 8.1% total sugar titer in the hydrolysate and an overall prehydrolysate liquor plus enzymatic hydrolysis conversion yield of 76.6%. At a much lower enzyme dosage of 0.044 g CTec2 enzyme product/g dry (unwashed) pretreated softwood, hydrolysis at 17% solids achieved 9.2% total sugar titer in the hydrolysate with an overall sugar yield of 85.0% in the combined prehydrolysate liquor and enzymatic hydrolysate. CLE Sugar has been demonstrated to be effective on hardwood and herbaceous biomass, making it truly feedstock flexible. Conclusions: Different options exist for integrating lignocellulosic sugar into sugar-using operations. A sugar conversion plant may be adjacent to a CLE Sugar plant, and the CLE Sugar can be concentrated from the initial 10% sugar as needed. Concentrated sugars, however, can be shipped to remote sites such as ethanol plants or other sugar users. In such cases, options for shipping a dense form of sugars include (1) pretreated biomass with enzyme addition, (2) lignocellulosic sugar syrup, and (3) lignocellulosic sugar solid. These could provide the advantage of maximizing the use of existing assets. [ABSTRACT FROM AUTHOR]

The Energy Independence and Security Act of 2007 mandates large increases in ethanol for transport, from about 6 billion gallons current annual production to 36 billion gallons by 2022. The act mandates that large portions of ethanol be cellulosic ethanol. Although there are a number of potential feedstocks for cellulosic ethanol, it is highly likely that much of the feedstock will come from the timber base as raw wood, especially in the early years before grass production, and alternative feedstock, has become well-developed and infrastructure networks created. This article uses a well-known timber projections model to estimate the impact of the potential near doubling of demand for industrial type resulting from the mandates and finds that real prices could raise 15–20%. It also projects a large increase in the importation of processed wood products as domestic wood products production is crowded out by high raw wood prices. [ABSTRACT FROM PUBLISHER]

As demand for energy increases in the United States, alternative energy sources are being sought both domestically and abroad. Biofuels have been promoted as a major source of alternative energy, but sustainable supply of biomass still remains a major challenge. Agroforestry offers a potential way to integrate perennial woody bioenergy crops with traditional agricultural crops to satisfy energy demands without sacrificing food production in the North Central Region of the United States. We suggest shelterbelts, alley cropping and working riparian buffer strips as ideal candidates for biomass production in agroforestry settings in this region. In addition to satisfying domestic energy demands, these systems could also potentially increase water quality, sequester carbon, improve aesthetics, and provide critical wildlife habitat. However, obstacles to implementing agroforestry systems for biomass production, such as a competitive price structure and stable markets, must be overcome before large-scale adoption by landowners. [ABSTRACT FROM AUTHOR]

Eastern forests of the US are valued both as a carbon sink and a wood resource. The amount of biomass that can be harvested sustainably from this biome for bioenergy without compromising the carbon sink is uncertain. Using past literature and previously validated models, we assessed four scenarios of biomass harvest in the eastern US: partial harvests of mixed hardwood forests, pine plantation management, short-rotation woody cropping systems, and forest residue removal. We also estimated the amount and location of abandoned agricultural lands in the eastern US that could be used for biomass production. Greater carbon storage was estimated to result from partial harvests and residue removals than from plantation management and short-rotation cropping. If woody feedstocks were cultivated with a combination of intensive management on abandoned lands and partial harvests of standing forest, we estimate that roughly 176 Tg biomass y-1 (~330,000 GWh or ~16 billion gallons of ethanol) could be produced sustainably from the temperate forest biome of the eastern US. This biomass could offset up to ~63 Tg C y-1 that are emitted from fossil fuels used for heat and power generation while maintaining a terrestrial C sink of ~8 Tg C y-1. [ABSTRACT FROM AUTHOR]

Agave is a succulent genus within the monocot family Agavaceae. The plants have a large rosette of thick fleshy leaves, each ending generally in a sharp point, and are native to arid and semi-arid regions from the southern USA to northern South America. The most important commercial species is Agave tequilana grown for production of tequila. Several cultivated species of Agave such as Agave sislana and Agave salmiana can perform well in areas where rainfall is insufficient for the cultivation of many C and C crops. The key feature of the crassulacean acid metabolism photosynthetic pathway used by agaves is the stomata opening and CO uptake during the night, thus allowing less water to be lost by transpiration. Alcoholic beverages, sweeteners, fibers, and some specialty chemicals are currently the main products coming from agave plants. The recovered information related to productivity, biofuel processability, by-products, etc. suggests that some Agave species have a real potential to compete economically with other bioenergy crops. But more than compete, it could complement the list of bioenergy crops due to its capacity to grow with very little rainfall and/or inputs and still reach good amount of biomass, so unused semi-arid land could be productive. Although Agave has great potential to be developed as a bioenergy crop, more laboratory and field research are needed. [ABSTRACT FROM AUTHOR]

Nonpoint source (NPS) pollutants such as phosphorus, nitrogen, sediment, and pesticides are the foremost sources of water contamination in many of the water bodies in the Midwestern agricultural watersheds. This problem is expected to increase in the future with the increasing demand to provide corn as grain or stover for biofuel production. Best management practices (BMPs) have been proven to effectively reduce the NPS pollutant loads from agricultural areas. However, in a watershed with multiple farms and multiple BMPs feasible for implementation, it becomes a daunting task to choose a right combination of BMPs that provide maximum pollution reduction for least implementation costs. Multi-objective algorithms capable of searching from a large number of solutions are required to meet the given watershed management objectives. Genetic algorithms have been the most popular optimization algorithms for the BMP selection and placement. However, previous BMP optimization models did not study pesticide which is very commonly used in corn areas. Also, with corn stover being projected as a viable alternative for biofuel production there might be unintended consequences of the reduced residue in the corn fields on water quality. Therefore, there is a need to study the impact of different levels of residue management in combination with other BMPs at a watershed scale. In this research the following BMPs were selected for placement in the watershed: (a) residue management, (b) filter strips, (c) parallel terraces, (d) contour farming, and (e) tillage. We present a novel method of combing different NPS pollutants into a single objective function, which, along with the net costs, were used as the two objective functions during optimization. In this study we used BMP tool, a database that contains the pollution reduction and cost information of different BMPs under consideration which provides pollutant loads during optimization. The BMP optimization was performed using a NSGA-II based search method. The model was tested for the selection and placement of BMPs in Wildcat Creek Watershed, a corn dominated watershed located in northcentral Indiana, to reduce nitrogen, phosphorus, sediment, and pesticide losses from the watershed. The Pareto optimal fronts (plotted as spider plots) generated between the optimized objective functions can be used to make management decisions to achieve desired water quality goals with minimum BMP implementation and maintenance cost for the watershed. Also these solutions were geographically mapped to show the locations where various BMPs should be implemented. The solutions with larger pollution reduction consisted of buffer filter strips that lead to larger pollution reduction with greater costs compared to other alternatives. [ABSTRACT FROM AUTHOR]

Biofuel greenhouse gas (GHG)-reduction standards calculated via life-cycle assessment are shown to be biased, even when indirect land-use change is included, because they are based on physical GHG emissions and uptakes and on simple aggregates of balances. We offer a GHG-reduction standard for biofuel production free of these biases, expressed for a range of discount rates and an upper bound on the GHG payback period. A numerical example, based on previously used data, reveals that converting two land types into ethanol in Brazil satisfies our biofuel emissions test, whereas in the United States no land type satisfies our criterion. [ABSTRACT FROM PUBLISHER]

Abstract: Kenaf (Hibiscus cannabinus L.) is a nonwoody fiber source with many uses. To evaluate the dry matter yield potential of kenaf at two locations in the southern High Plains of the USA and the effects of late planting/late emergence as a possible replacement for hail damaged cotton, four varieties were grown in 2004 and 2005 at New Mexico State University''s Agricultural Science Centers at Clovis, under limited irrigation, and Tucumcari, under rainfed conditions. Each study was a randomized complete block design having four replicates. A year×location interaction existed (P <0.0469) for kenaf yield largely due to precipitation amount and distribution. Either late planting or late emergence due to low soil moisture at planting significantly reduced yields (3.62 vs. 0.63Mgha−1 for mid-May planting and emergence and early July emergence or planting, respectively, P <0.0001). Consequently, kenaf would not be suitable for recovering input costs when planted after failure of cotton. The very late maturing variety Gregg had consistently lower numeric yields than Dowling, Everglades 41, and Tainung 2 in all comparisons, with the strongest trend within the emergence date comparison (P <0.0912). Kenaf varieties should be selected for any location that finish blooming approximately three to four weeks prior to the average first autumn freeze to allow for maximum growth. [Copyright &y& Elsevier]

Ethanol has been embraced enthusiastically as a solution to many problems, including national energy security, global warming, air pollution, farm incomes, and local economic development. The industry has boomed in the United States: There were 54 ethanol plants in 2000, 134 by the end of 2007, 171 in mid-September 2008. Estimates of the industry's effects on local economies vary wildly, chiefly because of assumptions regarding the corn industry. This article presents an overview of the industry, its location, and the public policy umbrella that supports its growth. It analyzes what happens to the local economy when a county adds an ethanol plant, demonstrates what must be done to modify input-output models to capture those effects, and applies the approach to proposed plants in four counties. An ethanol plant provides the enticing benefits of a manufacturing plant with 35 to 40 jobs, but several characteristics and uncertainties of the industry merit a careful look when making local economic development decisions. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Greenhouse gas (GHG) emissions constitute a global problem. The need for agricultural involvement in GHG mitigation has been widely recognized since the 1990s. The concept of C sinks. C credits, and emission trading has attracted special interests in herbaceous and woody species as energy crops and source of biofuel feedstock. Bioenergy crops are defined as any plant material used to produce Bioenergy. These crops have the capacity to produce large volume of biomass, high energy potential, and can be grown in marginal soils. Planting bioenergy crops in degraded soils is one of the promising agricultural options with C sequestration rates ranging from 0.6 to 3.0 Mg C ha-1 yr-1. About 60 million hectares (Mha) of land is available in the United States and 757 Mha in the world to grow bioenergy crops. With an energy offset of 1 kg of C in biomass per 0.6 kg of C in fossil fuel, there exists a vast potential of offsetting fossil fuel emission. Bioenergy crops have the potential to sequester approximately 318 Tg C yr-1 in the United States and 1631 Tg C yr-1 worldwide. Bioenergy crops consist of herbaceous bunch-type grasses and short-rotation woody perennials. Important grasses include switchgrass (Panicum virgatum L.), elephant grass (Pennissetum purpureum Schum.), tall fescue (Fetusca arundinacea L.), etc. Important among short-rotation woody perennials are poplar (Populus spp.), willow (Salix spp.), mesquite (Prosopis spp.), etc. The emissions of CO2 from using switchgrass as energy crop is 1.9 kg C Gj-1 compared with 13.8, 22.3, and 24.6 kg C Gj-1 from using gas, petroleum, and coal, respectively. Mitigation of GHG emissions cannot be achieved by C sinks alone, a substantial reduction in fossil fuel combustion will be necessary. Carbon sequestration and fossil fuel offset by bioenergy crops is an important component of a possible total societal response to a GHG emission reduction initiative. [ABSTRACT FROM AUTHOR]