Hazardous Waste Cleanup: West Valley Demonstration Project USDOE in West Valley, New York

EPA Pesticide Factsheets

The U.S. Department of Energy's West Valley Demonstration Project is located at 10282 Rock Spring Road in West Valley, New York. This is a 167 acre, Department of Energy (DOE)-operated portion of a 3,300-acre site owned by the New York State Energy

Antimicrobial and anti-inflammatory activity of switchgrass-derived extractives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Labbe, Nicole; Ownley, Bonnie H.; Gwinn, Kimberly D.

Switchgrass is an increasingly important biofuel crop, but knowledge of switchgrass fungal pathogens is not extensive. The purpose of this research was to identify the fungal pathogens that decrease crop yield of switchgrass grown in Tennessee and to investigate a potential sustainable disease management strategy from a value-added by-product of the switchgrass biofuel conversion process. The specific objectives were 1) to identify and characterize prevalent fungal pathogens of switchgrass in Tennessee, 2) assess switchgrass seed produced in the United States for seedborne fungal pathogens, and 3) evaluate switchgrass extractives for antimicrobial activity against plant pathogens.

Identifying Differences in Abiotic Stress Gene Networks between Lowland and Upland Ecotypes of Switchgrass (DE-SC0008338)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Childs, Kevin; Buell, Robin; Zhao, Bingyu

Switchgrass (Panicum virgatum) is a warm-season C4 grass that is a target lignocellulosic biofuel species for use in the United States due to its local adaption capabilities and high biomass accumulation. Two ecotypes of switchgrass have been described. Members of the lowland ecotype are taller, have narrower leaf blades and generate more biomass compared to individuals from the upland ecotype. Additionally, lowland plants are generally found in the southern United States while upland switchgrass is more typically present in the northern United States. These differences are important as it is envisioned that switchgrass for biofuel production will typically be grownmore » on marginal lands in the northern United States to supplement and diversify farmers' traditional crop incomes. While lowland switchgrass is more productive, it has poor winter survivability in northern latitudes where upland switchgrass is expected to be grown for biofuel use. Abiotic stresses likely to be encountered by switchgrass include drought and salinity. Despite initially being described as preferring wetter environments, members of the lowland ecotype have been characterized as being more drought tolerant than plants of the upland ecotype. Nonetheless, direct trials have indicated that variation for drought tolerance exists in both ecotypes, but prior to this project, only a relatively small number of switchgrass lines had been tested for drought responses. Similarly, switchgrass cultivars have not been widely tested for salt tolerance, but a few studies have shown that even mild salt stress can inhibit growth. The effects of drought and salt stress on plant growth are complex. Both drought and salinity affect the osmotic potential of plant cells and negatively affect plant growth due to reduced water potential and reduced photosynthesis that results from lower stomatal conductance of CO 2. Plants respond to drought and salt stress by activating genes that directly attempt to reduce the

Pumpernickel Valley Geothermal Project Thermal Gradient Wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Z. Adam Szybinski

2006-01-01

The Pumpernickel Valley geothermal project area is located near the eastern edge of the Sonoma Range and is positioned within the structurally complex Winnemucca fold and thrust belt of north-central Nevada. A series of approximately north-northeast-striking faults related to the Basin and Range tectonics are superimposed on the earlier structures within the project area, and are responsible for the final overall geometry and distribution of the pre-existing structural features on the property. Two of these faults, the Pumpernickel Valley fault and Edna Mountain fault, are range-bounding and display numerous characteristics typical of strike-slip fault systems. These characteristics, when combined withmore » geophysical data from Shore (2005), indicate the presence of a pull-apart basin, formed within the releasing bend of the Pumpernickel Valley – Edna Mountain fault system. A substantial body of evidence exists, in the form of available geothermal, geological and geophysical information, to suggest that the property and the pull-apart basin host a structurally controlled, extensive geothermal field. The most evident manifestations of the geothermal activity in the valley are two areas with hot springs, seepages, and wet ground/vegetation anomalies near the Pumpernickel Valley fault, which indicate that the fault focuses the fluid up-flow. There has not been any geothermal production from the Pumpernickel Valley area, but it was the focus of a limited exploration effort by Magma Power Company. In 1974, the company drilled one exploration/temperature gradient borehole east of the Pumpernickel Valley fault and recorded a thermal gradient of 160oC/km. The 1982 temperature data from five unrelated mineral exploration holes to the north of the Magma well indicated geothermal gradients in a range from 66 to 249oC/km for wells west of the fault, and ~283oC/km in a well next to the fault. In 2005, Nevada Geothermal Power Company drilled four geothermal gradient wells

Hybridization of downregulated-COMT transgenic switchgrass lines with field selected switchgrass for improved biomass traits

USDA-ARS?s Scientific Manuscript database

Transgenic switchgrass (Panicum virgatum L.) has been produced for improved cell walls for biofuels. Downregulated caffeic acid 3-O-methyltransferase (COMT) switchgrass produced significantly more biomass and biofuel than the non-transgenic progenitor line. In the present study we sought to further...

Hybridization of downregulated-COMT transgenic switchgrass lines with field-selected switchgrass for improved biomass traits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Holly L.; Alexander, Lisa W.; Mazarei, Mitra

Transgenic switchgrass (Panicum virgatum L.) has been produced for improved cell walls for biofuels. For instance, downregulated caffeic acid 3-O-methyltransferase (COMT) switchgrass produced significantly more biomass and biofuel than the non-transgenic progenitor line. In this present study we sought to further improve biomass characteristics by crossing the downregulated COMT T 1 lines with high-yielding switchgrass accessions in two genetic backgrounds ('Alamo' and 'Kanlow'). Crosses and T 2 progeny analyses were made under greenhouse conditions to assess maternal effects, plant morphology and yield, and cell wall traits. Female parent type influenced morphology, but had no effect on cell wall traits. Tmore » 2 hybrids produced with T 1 COMT-downregulated switchgrass as the female parent were taller, produced more tillers, and produced 63% more biomass compared with those produced using the field selected accession as the female parent. Transgene status (presence or absence of transgene) influenced both growth and cell wall traits. T 2 transgenic hybrids were 7% shorter 80 days after sowing and produced 43% less biomass than non-transgenic null-segregant hybrids. Cell wall-related differences included lower lignin content, reduced syringyl-to-guaiacyl (S/G) lignin monomer ratio, and a 12% increase in total sugar release in the T 2 transgenic hybrids compared to non-transgenic null segregants. This is the first study to evaluate the feasibility of transferring the low-recalcitrance traits associated with a transgenic switchgrass line into high-yielding field varieties in an attempt to improve growth-related traits. Lastly, our results provide insights into the possible improvement of switchgrass productivity via biotechnology paired with plant breeding.« less

Hybridization of downregulated-COMT transgenic switchgrass lines with field-selected switchgrass for improved biomass traits

DOE PAGES

Baxter, Holly L.; Alexander, Lisa W.; Mazarei, Mitra; ...

2016-01-21

Transgenic switchgrass (Panicum virgatum L.) has been produced for improved cell walls for biofuels. For instance, downregulated caffeic acid 3-O-methyltransferase (COMT) switchgrass produced significantly more biomass and biofuel than the non-transgenic progenitor line. In this present study we sought to further improve biomass characteristics by crossing the downregulated COMT T 1 lines with high-yielding switchgrass accessions in two genetic backgrounds ('Alamo' and 'Kanlow'). Crosses and T 2 progeny analyses were made under greenhouse conditions to assess maternal effects, plant morphology and yield, and cell wall traits. Female parent type influenced morphology, but had no effect on cell wall traits. Tmore » 2 hybrids produced with T 1 COMT-downregulated switchgrass as the female parent were taller, produced more tillers, and produced 63% more biomass compared with those produced using the field selected accession as the female parent. Transgene status (presence or absence of transgene) influenced both growth and cell wall traits. T 2 transgenic hybrids were 7% shorter 80 days after sowing and produced 43% less biomass than non-transgenic null-segregant hybrids. Cell wall-related differences included lower lignin content, reduced syringyl-to-guaiacyl (S/G) lignin monomer ratio, and a 12% increase in total sugar release in the T 2 transgenic hybrids compared to non-transgenic null segregants. This is the first study to evaluate the feasibility of transferring the low-recalcitrance traits associated with a transgenic switchgrass line into high-yielding field varieties in an attempt to improve growth-related traits. Lastly, our results provide insights into the possible improvement of switchgrass productivity via biotechnology paired with plant breeding.« less

75 FR 70020 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-16

... office on Central Valley Project water conservation best management practices that shall ``* * * develop... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior ACTION: Notice of Availability. SUMMARY: The...

77 FR 64544 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-22

... Central Valley Project water conservation best management practices that shall ``develop criteria for... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The...

76 FR 12756 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... office on Central Valley Project water conservation best management practices that shall ``* * * develop... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The...

76 FR 54251 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

... and administer an office on Central Valley Project water conservation best management practices that... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The...

78 FR 21414 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-10

... Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are available for review... establish and administer an office on Central Valley Project water conservation best management practices...

75 FR 38538 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... to establish and administer an office on Central Valley Project water conservation best management... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The...

Research and Technology Development for Genetic Improvement of Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kausch, Albert; Rhodes, Richard

This research adds to the understanding of switchgrass genetics and the increasing of biomass relevant to production of bioenergy. Switchgrass, Panicum virgatum L., and its related species are well known as potential bioenergy crops since the early 1990s. There are global economic, political, US national security and environmental pressures to increase renewable biofuel production and utilization to offset gasoline and diesel fuel use and climate change, especially in the liquid fuel transportation sector. To realize the potential of bioenergy crops, rapid genetic improvement of the most promising perennial grass feedstocks, such as switchgrass, are anticipated by current genomics, association genetics,more » marker assisted breeding, hybrid plant development, advanced tissue culture, conventional genetics and other approaches to increase yield, processability, and regional adaptation. The technical effectiveness and economic feasibility of the methods or techniques investigated are demonstrated by several publications, presentations and patents produced as an outcome and deliverable of this research. This project is of a broad benefit to the public not only through the dissemination of this information but also to the development of new methods which will be applied to future bioenergy crop improvement as well as other crops.« less

Production of polyhydroxybutyrate in switchgrass

DOEpatents

Somleva, Mariya N.; Snell, Kristi D.; Beaulieu, Julie; Peoples, Oliver P.; Garrison, Bradley; Patterson, Nii

2013-07-16

Transgenic plants, plant material, and plant cells for synthesis of polyhydroxyalkanoates, preferably poly(3-hydroxybutyrate) (also referred to a as PHB) are provided. Preferred plants that can be genetically engineered to produce PHB include plants that do not normally produce storage products such as oils and carbohydrates, and plants that have a C.sub.4 NAD-malic enzyme photosynthetic pathway. Such plants also advantageously produce lignocellulosic biomass that can be converted into biofuels. An exemplary plant that can be genetically engineered to produce PHB and produce lignocellulosic biomass is switchgrass, Panicum virgatum L. A preferred cultivar of switchgrass is Alamo. Other suitable cultivars of switchgrass include but are not limited to Blackwell, Kanlow, Nebraska 28, Pathfinder, Cave-in-Rock, Shelter and Trailblazer.

Transcriptional Analysis of Flowering Time in Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tornqvist, Carl-Erik; Vaillancourt, Brieanne; Kim, Jeongwoon

Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in switchgrass that would assist in development of cultivars with longer vegetative phases through delayed flowering. RNA sequencing was used to assess genome-wide expression profiles across a developmental series between switchgrass genotypes belonging to the two main ecotypes: upland, typically earlymore » flowering, and lowland, typically late flowering. Leaf blades and tissues enriched for the shoot apical meristem (SAM) were collected in a developmental series from emergence through anthesis for RNA extraction. RNA from samples that flanked the SAM transition stage was sequenced for expression analyses. The analyses revealed differential expression patterns between early- and late-flowering genotypes for known flowering time orthologs. Namely, genes shown to play roles in photoperiod response and the circadian clock in other species were identified as potential candidates for regulating flowering time in the switchgrass genotypes analyzed. Based on their expression patterns, many of the differentially expressed genes could also be classified as putative promoters or repressors of flowering. The candidate genes presented here may be used to guide switchgrass improvement through marker-assisted breeding and/or transgenic or gene editing approaches.Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in

Transcriptional Analysis of Flowering Time in Switchgrass

DOE PAGES

Tornqvist, Carl-Erik; Vaillancourt, Brieanne; Kim, Jeongwoon; ...

2017-04-27

Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in switchgrass that would assist in development of cultivars with longer vegetative phases through delayed flowering. RNA sequencing was used to assess genome-wide expression profiles across a developmental series between switchgrass genotypes belonging to the two main ecotypes: upland, typically earlymore » flowering, and lowland, typically late flowering. Leaf blades and tissues enriched for the shoot apical meristem (SAM) were collected in a developmental series from emergence through anthesis for RNA extraction. RNA from samples that flanked the SAM transition stage was sequenced for expression analyses. The analyses revealed differential expression patterns between early- and late-flowering genotypes for known flowering time orthologs. Namely, genes shown to play roles in photoperiod response and the circadian clock in other species were identified as potential candidates for regulating flowering time in the switchgrass genotypes analyzed. Based on their expression patterns, many of the differentially expressed genes could also be classified as putative promoters or repressors of flowering. The candidate genes presented here may be used to guide switchgrass improvement through marker-assisted breeding and/or transgenic or gene editing approaches.Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in

ESTABLISHMENT AND EVALUATION OF SWITCHGRASS ON RECLAIMED MINE SOIL [English

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lang, David; Shankle, Brandon; Oswalt, Ernest

Switchgrass (Panicum virgatum L.) is a native warm season perennial grass that has productive potential of up to 20 Mg ha-1 of biomass and it persists for decades when harvested once per year. Switchgrass provides excellent ground cover and soil stabilization once established and contributes to soil sequestration of new carbon. Slow establishment on newly reclaimed soil, however, provides for significant erosive opportunities thereby requiring initial soil stabilization with a cover crop. Several planting options were evaluated on two topsoil substitute soils. The planting options included: 1) an existing stand of bermudagrass (Cynodon dactylon L.) that was killed with glyphosatemore » followed by disking in red oxidized topsoil substitute and prime farmland topsoil respread in 2007, 2) red oxidized topsoil substitute was seeded directly with switchgrass, 3) browntop millet (Panicum ramosum) was established with switchgrass, 4) or switchgrass was established in senescing browntop millet or wheat without tillage. Switchgrass was successfully established into a bermudagrass sod that had been killed with herbicides and disked as well as into a senescing stand of browntop millet or wheat. Significant soil erosion occurred on the disked area in 2008 leading to considerable repair work followed by planting wheat. Disked areas that did not erode had an excellent stand of switchgrass with 23.3 plants m-2 in November, 2008. Eroded areas replanted in April, 2009 into senescing wheat had 46 plants m-2 by July, 2009. The area planted directly into newly respread soil in May, 2009 was eroded severely by a 75 mm thunderstorm and was repaired, disked and replanted to switchgrass and browntop millet. Switchgrass seeded with browntop millet had a sparse switchgrass stand and was replanted to switchgrass in August, 2009. Rainfall volumes from August, 2009 to October, 2009 totaled 750 mm, but new erosion damage in areas successfully planted to switchgrass has been minimal.« less

Associations with flowering time, latitude, and climate in switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass is a North American perennial grass and emerging bioenergy feedstock, and increasing biomass yields will improve the economic viability of switchgrass as a bioenergy crop. Flowering time is an important determinant of biomass yields in switchgrass because the majority of biomass accumula...

Lower Merrimack Valley Workplace Education Project. Final Report.

ERIC Educational Resources Information Center

Norris, Cynthia Zylkuski; Breen, Patricia K.

A description is provided of the Lower Merrimack Valley Workplace Education Project (WEP), an educational project that offers English-as-a-Second-Language (ESL) and job-specific education classes to hourly employees in the Semiconductor Division of Alpha Industries. The challenge of the project was to create a WEP that could accommodate the…

Sulfite (SPORL) pretreatment of switchgrass for enzymatic saccharification

Treesearch

D.S. Zhang; Q. Yang; J.Y. Zhu; X.J. Pan

2013-01-01

SPORL (Sulfite Pretreatment to Overcome Recalcitrance of Lignocellulose) pretreatment was applied to switchgrass and optimized through an experimental design using Response Surface Methodology within the range of temperature (163–197 °C), time (3–37 min), sulfuric acid dosage (0.8–4.2% on switchgrass), and sodium sulfite dosage (0.6–7.4% on switchgrass)....

76 FR 58840 - Central Valley Project Improvement Act; Refuge Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-22

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act; Refuge Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: To meet the requirements of the Central Valley Project Improvement Act of 1992 (CVPIA) and subsequent...

Efficient Methods of Estimating Switchgrass Biomass Supplies

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is being developed as a biofuel feedstock for the United States. Efficient and accurate methods to estimate switchgrass biomass feedstock supply within a production area will be required by biorefineries. Our main objective was to determine the effectiveness of in...

Advances in biotechnology and genomics of switchgrass

PubMed Central

2013-01-01

Switchgrass (Panicum virgatum L.) is a C4 perennial warm season grass indigenous to the North American tallgrass prairie. A number of its natural and agronomic traits, including adaptation to a wide geographical distribution, low nutrient requirements and production costs, high water use efficiency, high biomass potential, ease of harvesting, and potential for carbon storage, make it an attractive dedicated biomass crop for biofuel production. We believe that genetic improvements using biotechnology will be important to realize the potential of the biomass and biofuel-related uses of switchgrass. Tissue culture techniques aimed at rapid propagation of switchgrass and genetic transformation protocols have been developed. Rapid progress in genome sequencing and bioinformatics has provided efficient strategies to identify, tag, clone and manipulate many economically-important genes, including those related to higher biomass, saccharification efficiency, and lignin biosynthesis. Application of the best genetic tools should render improved switchgrass that will be more economically and environmentally sustainable as a lignocellulosic bioenergy feedstock. PMID:23663491

Production and supply logistics of switchgrass as an energy feedstock

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a warm-season (C4), perennial grass that is native to the tallgrass ecoregion of North America (Figure 1). Historically, switchgrass has been used for summer forage, hay, ensiling, or in conservation plantings. At the end of the 20th century, switchgrass was de...

Transcriptional analysis of flowering time in switchgrass

USDA-ARS?s Scientific Manuscript database

Over the past two decades, switchgrass (Panicum virgatum) has emerged as a viable biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; a longer vegetative stage leads to an increase in overall biomass yield. The goal of this study was to gain insight into the...

Switchgrass (Panicum virgatum L.) promoters for green tissue-specific expression of the MYB4 transcription factor for reduced-recalcitrance transgenic switchgrass

DOE PAGES

Liu, Wusheng; Mazarei, Mitra; Ye, Rongjian; ...

2018-04-24

Genetic engineering of switchgrass (Panicum virgatum L.) for reduced cell wall recalcitrance and improved biofuel production has been a long pursued goal. Up to now, constitutive promoters have been used to direct the expression of cell wall biosynthesis genes toward attaining that goal. While generally sufficient to gauge a transgene's effects in the heterologous host, constitutive overexpression often leads to undesirable plant phenotypic effects. Green tissue-specific promoters from switchgrass are potentially valuable to directly alter cell wall traits exclusively in harvestable aboveground biomass while not changing root phenotypes. We identified and functionally characterized three switchgrass green tissue-specific promoters and assessedmore » marker gene expression patterns and intensity in stably transformed rice (Oryza sativa L.), and then used them to direct the expression of the switchgrass MYB4 (PvMYB4) transcription factor gene in transgenic switchgrass to endow reduced recalcitrance in aboveground biomass. These promoters correspond to photosynthesis-related light-harvesting complex II chlorophyll-a/b binding gene (PvLhcb), phosphoenolpyruvate carboxylase (PvPEPC), and the photosystem II 10 kDa R subunit (PvPsbR). Real-time RT-PCR analysis detected their strong expression in the aboveground tissues including leaf blades, leaf sheaths, internodes, inflorescences, and nodes of switchgrass, which was tightly up-regulated by light. Stable transgenic rice expressing the GUS reporter under the control of each promoter (756-2005 bp in length) further confirmed their strong expression patterns in leaves and stems. With the exception of the serial promoter deletions of PvLhcb, all GUS marker patterns under the control of each 5'-end serial promoter deletion were not different from that conveyed by their respective promoters. All of the shortest promoter fragments (199-275 bp in length) conveyed strong green tissue-specific GUS expression in transgenic rice

Switchgrass (Panicum virgatum L.) promoters for green tissue-specific expression of the MYB4 transcription factor for reduced-recalcitrance transgenic switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wusheng; Mazarei, Mitra; Ye, Rongjian

Genetic engineering of switchgrass (Panicum virgatum L.) for reduced cell wall recalcitrance and improved biofuel production has been a long pursued goal. Up to now, constitutive promoters have been used to direct the expression of cell wall biosynthesis genes toward attaining that goal. While generally sufficient to gauge a transgene's effects in the heterologous host, constitutive overexpression often leads to undesirable plant phenotypic effects. Green tissue-specific promoters from switchgrass are potentially valuable to directly alter cell wall traits exclusively in harvestable aboveground biomass while not changing root phenotypes. We identified and functionally characterized three switchgrass green tissue-specific promoters and assessedmore » marker gene expression patterns and intensity in stably transformed rice (Oryza sativa L.), and then used them to direct the expression of the switchgrass MYB4 (PvMYB4) transcription factor gene in transgenic switchgrass to endow reduced recalcitrance in aboveground biomass. These promoters correspond to photosynthesis-related light-harvesting complex II chlorophyll-a/b binding gene (PvLhcb), phosphoenolpyruvate carboxylase (PvPEPC), and the photosystem II 10 kDa R subunit (PvPsbR). Real-time RT-PCR analysis detected their strong expression in the aboveground tissues including leaf blades, leaf sheaths, internodes, inflorescences, and nodes of switchgrass, which was tightly up-regulated by light. Stable transgenic rice expressing the GUS reporter under the control of each promoter (756-2005 bp in length) further confirmed their strong expression patterns in leaves and stems. With the exception of the serial promoter deletions of PvLhcb, all GUS marker patterns under the control of each 5'-end serial promoter deletion were not different from that conveyed by their respective promoters. All of the shortest promoter fragments (199-275 bp in length) conveyed strong green tissue-specific GUS expression in transgenic rice

The T-REX valley wind intercomparison project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidli, J; Billings, B J; Burton, R

2008-08-07

An accurate simulation of the evolution of the atmospheric boundary layer is very important, as the evolution of the boundary layer sets the stage for many weather phenomena, such as deep convection. Over mountain areas the evolution of the boundary layer is particularly complex, due to the nonlinear interaction between boundary layer turbulence and thermally-induced mesoscale wind systems, such as the slope and valley winds. As the horizontal resolution of operational forecasts progresses to finer and finer resolution, more and more of the thermally-induced mesoscale wind systems can be explicitly resolved, and it is very timely to document the currentmore » state-of-the-art of mesoscale models at simulating the coupled evolution of the mountain boundary layer and the valley wind system. In this paper we present an intercomparison of valley wind simulations for an idealized valley-plain configuration using eight state-of-the-art mesoscale models with a grid spacing of 1 km. Different sets of three-dimensional simulations are used to explore the effects of varying model dynamical cores and physical parameterizations. This intercomparison project was conducted as part of the Terrain-induced Rotor Experiment (T-REX; Grubisic et al., 2008).« less

Genetic control of flowering and biomass in switchgrass

USDA-ARS?s Scientific Manuscript database

Early flowering can negatively affect biomass yield of switchgrass. In temperate regions of the USA, flowering occurs in switchgrass around the time of peak biomass yield (about 5 to 8 weeks prior to killing frost), effectively reducing the length of the growing season. The use of late-flowering swi...

Transmission of Switchgrass mosaic virus by Graminella aureovitatta

USDA-ARS?s Scientific Manuscript database

Switchgrass mosaic virus (SwMV) was identified in switchgrass (Panicum virgatum) and was proposed as a new marafivirus based on its genome sequence and comparison with its closest relative, Maize rayado fino virus (MRFV), a type member of the genus, Marafivirus. MRFV only infects maize (Zea mays) an...

The WRKY transcription factor family and senescence in switchgrass.

PubMed

Rinerson, Charles I; Scully, Erin D; Palmer, Nathan A; Donze-Reiner, Teresa; Rabara, Roel C; Tripathi, Prateek; Shen, Qingxi J; Sattler, Scott E; Rohila, Jai S; Sarath, Gautam; Rushton, Paul J

2015-11-09

Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. All potential WRKY genes present in the version 1.0 of the switchgrass genome were identified and curated using manual and bioinformatic methods. Expression profiles of WRKY genes in switchgrass flag leaf RNA-Seq datasets were analyzed using clustering and network analyses tools to identify both WRKY and WRKY-associated gene co-expression networks during leaf development and senescence onset. We identified 240 switchgrass WRKY genes including members of the RW5 and RW6 families of resistance proteins. Weighted gene co-expression network analysis of the flag leaf transcriptomes across development readily separated clusters of co-expressed genes into thirteen modules. A visualization highlighted separation of modules associated with the early and senescence-onset phases of flag leaf growth. The senescence-associated module contained 3000 genes including 23 WRKYs. Putative promoter regions of senescence-associated WRKY genes contained several cis-element-like sequences suggestive of responsiveness to both senescence and stress signaling pathways. A phylogenetic comparison of senescence-associated WRKY genes from switchgrass flag leaf with senescence-associated WRKY genes from other plants revealed notable hotspots in Group I, IIb, and IIe of the phylogenetic tree. We have identified and named 240 WRKY genes in the switchgrass genome. Twenty three of these genes show elevated mRNA levels during the onset of flag leaf senescence. Eleven of the WRKY genes were found in hotspots of related senescence-associated genes from multiple species and thus represent promising targets for future switchgrass genetic improvement. Overall, individual WRKY gene expression profiles could be readily linked to developmental stages of flag leaves.

A Genomics Approach to Deciphering Lignin Biosynthesis in Switchgrass[W

PubMed Central

Shen, Hui; Mazarei, Mitra; Hisano, Hiroshi; Escamilla-Trevino, Luis; Fu, Chunxiang; Pu, Yunqiao; Rudis, Mary R.; Tang, Yuhong; Xiao, Xirong; Jackson, Lisa; Li, Guifen; Hernandez, Tim; Chen, Fang; Ragauskas, Arthur J.; Stewart, C. Neal; Wang, Zeng-Yu; Dixon, Richard A.

2013-01-01

It is necessary to overcome recalcitrance of the biomass to saccharification (sugar release) to make switchgrass (Panicum virgatum) economically viable as a feedstock for liquid biofuels. Lignin content correlates negatively with sugar release efficiency in switchgrass, but selecting the right gene candidates for engineering lignin biosynthesis in this tetraploid outcrossing species is not straightforward. To assist this endeavor, we have used an inducible switchgrass cell suspension system for studying lignin biosynthesis in response to exogenous brassinolide. By applying a combination of protein sequence phylogeny with whole-genome microarray analyses of induced cell cultures and developing stem internode sections, we have generated a list of candidate monolignol biosynthetic genes for switchgrass. Several genes that were strongly supported through our bioinformatics analysis as involved in lignin biosynthesis were confirmed by gene silencing studies, in which lignin levels were reduced as a result of targeting a single gene. However, candidate genes encoding enzymes involved in the early steps of the currently accepted monolignol biosynthesis pathway in dicots may have functionally redundant paralogues in switchgrass and therefore require further evaluation. This work provides a blueprint and resources for the systematic genome-wide study of the monolignol pathway in switchgrass, as well as other C4 monocot species. PMID:24285795

Estimating switchgrass productivity in the Great Plains using satellite vegetation index and site environmental variables

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.; Howard, Daniel M.

2015-01-01

Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to assess the environmental conditions of switchgrass over large areas and across different geographic locations. The main goal of this study is to develop a data-driven multiple regression switchgrass productivity model and identify the optimal climate and environment conditions for the highly productive switchgrass in the Great Plains (GP). Environmental and climate variables used in the study include elevation, soil organic carbon, available water capacity, climate, and seasonal weather. Satellite-derived growing season averaged Normalized Difference Vegetation Index (GSN) was used as a proxy for switchgrass productivity. Multiple regression analyses indicate that there are strong correlations between site environmental variables and switchgrass productivity (r = 0.95). Sufficient precipitation and suitable temperature during the growing season (i.e., not too hot or too cold) are favorable for switchgrass growth. Elevation and soil characteristics (e.g., soil available water capacity) are also an important factor impacting switchgrass productivity. An anticipated switchgrass biomass productivity map for the entire GP based on site environmental and climate conditions and switchgrass productivity model was generated. Highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study can help land managers and biofuel plant investors better understand the general environmental and climate conditions influencing switchgrass growth and make optimal land use decisions regarding switchgrass development in the GP.

Extensive genetic diversity present within North American switchgrass germplasm

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a perennial, native North American grass currently grown for ecological restoration and forage purposes that has potential as a biofuel feedstock crop. Understanding the genetic diversity of switchgrass can provide insight into allelic variants important in devel...

Switchgrass cultivars alter microbial contribution to deep soil C

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a perennial, cellulosic biofuel feedstock capable of growing under a wide variety of climatic conditions on land marginally suited to cultivated crops. Due to its perennial nature and deep rooting characteristics, switchgrass contributes to soil C sequestration ...

Switchgrass Genetics: Status, Future Directions, and Implications for Simulations

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a C4 polymorphic species with two ploidy levels, two major and numerous minor ecotypes adapted to different plant hardiness zones and ecoregions in its range. Switchgrasses are determinate, photoperiod sensitive, and require short days to induce flowering. Photo...

Genetic variation of flowering time and biomass in switchgrass

USDA-ARS?s Scientific Manuscript database

The timing of phase change from juvenile (vegetative) to adult with reproductive competence is a key factor influencing biomass yield of switchgrass. A decline in biomass yield is typically observed in switchgrass immediately following completion of flowering. In temperate regions of the USA, if flo...

Microwave pretreatment of switchgrass for bioethanol production

NASA Astrophysics Data System (ADS)

Keshwani, Deepak Radhakrishin

Lignocellulosic materials are promising alternative feedstocks for bioethanol production. These materials include agricultural residues, cellulosic waste such as newsprint and office paper, logging residues, and herbaceous and woody crops. However, the recalcitrant nature of lignocellulosic biomass necessitates a pretreatment step to improve the yield of fermentable sugars. The overall goal of this dissertation is to expand the current state of knowledge on microwave-based pretreatment of lignocellulosic biomass. Existing research on bioenergy and value-added applications of switchgrass is reviewed in Chapter 2. Switchgrass is an herbaceous energy crop native to North America and has high biomass productivity, potentially low requirements for agricultural inputs and positive environmental impacts. Based on results from test plots, yields in excess of 20 Mg/ha have been reported. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from run-off, soil remediation and provision of habitats for grassland birds. Published research on pretreatment of switchgrass reported glucose yields ranging from 70-90% and xylose yields ranging from 70-100% after hydrolysis and ethanol yields ranging from 72-92% after fermentation. Other potential value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Research on microwave-based pretreatment of switchgrass and coastal bermudagrass is presented in Chapter 3. Pretreatments were carried out by immersing the biomass in dilute chemical reagents and exposing the slurry to microwave radiation at 250 watts for residence times ranging from 5 to 20 minutes. Preliminary experiments identified alkalis as suitable chemical reagents for microwave-based pretreatment. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent. Under optimum pretreatment

Switchgrass ecotypes alter microbial contribution to deep-soil C

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland), little is known about the impact of plant belowground productivity on mic...

Switchgrass and Giant Miscanthus Biomass and Theoretical Ethanol Production from Reclaimed Mine Lands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfrum, Edward J; Scagline-Mellor, Steffany; Griggs, Thomas

Switchgrass (Panicum virgatum L.) and giant miscanthus (Miscanthus x giganteus Greef & Deuter ex Hodkinson & Renvoize) are productive on marginal lands in the eastern USA, but their productivity and composition have not been compared on mine lands. Our objectives were to compare biomass production, composition, and theoretical ethanol yield (TEY) and production (TEP) of these grasses on a reclaimed mined site. Following 25 years of herbaceous cover, vegetation was killed and plots of switchgrass cultivars Kanlow and BoMaster and miscanthus lines Illinois and MBX-002 were planted in five replications. Annual switchgrass and miscanthus yields averaged 5.8 and 8.9 Mgmore » dry matter ha-1, respectively, during 2011 to 2015. Cell wall carbohydrate composition was analyzed via near-infrared reflectance spectroscopy with models based on switchgrass or mixed herbaceous samples including switchgrass and miscanthus. Concentrations were higher for glucan and lower for xylan in miscanthus than in switchgrass but TEY did not differ (453 and 450 L Mg-1, respectively). In response to biomass production, total ethanol production was greater for miscanthus than for switchgrass (5594 vs 3699 L ha-1), did not differ between Kanlow and BoMaster switchgrass (3880 and 3517 L ha-1, respectively), and was higher for MBX-002 than for Illinois miscanthus (6496 vs 4692 L ha-1). Relative to the mixed feedstocks model, the switchgrass model slightly underpredicted glucan and slightly overpredicted xylan concentrations. Estimated TEY was slightly lower from the switchgrass model but both models distinguished genotype, year, and interaction effects similarly. Biomass productivity and TEP were similar to those from agricultural sites with marginal soils.« less

Natural cellulose fibers from switchgrass with tensile properties similar to cotton and linen.

PubMed

Reddy, Narendra; Yang, Yiqi

2007-08-01

We report the production and characteristics of natural cellulose fibers obtained from the leaves and stems of switchgrass. In this paper, the composition, structure and properties of fibers obtained from the leaves and stem of switchgrass have been studied in comparison to the common natural cellulose fibers, such as cotton, linen and kenaf. The leaves and stems of switchgrass have tensile properties intriguingly similar to that of linen and cotton, respectively. Fibers were obtained from the leaves and stems of switchgrass using a simple alkaline extraction and the structure and properties of the fibers were studied. Fibers obtained from switchgrass leaves have crystallinity of 51%, breaking tenacity of 5.5 g per denier (715 MPa) and breaking elongation of 2.2% whereas the corresponding values for fibers obtained from switchgrass stems are 46%, 2.7 g per denier and 6.8%, respectively. Switchgrass is a relatively easy to grow and high yield biomass crop that can be source to partially substitute the natural and synthetic fibers currently in use. We hope that this research will stimulate interests in using switchgrass as a novel fiber crop in addition to being promoted as a potential source for biofuels. (c) 2007 Wiley Periodicals, Inc.

Effects of torrefaction and densification on switchgrass pyrolysis products

DOE PAGES

Yang, Zixu; Sarkar, Madhura; Kumar, Ajay; ...

2014-12-01

Abstract The pyrolysis behaviors of four types of pretreated switchgrass (torrefied at 230 and 270 °C, densification, and torrefaction at 270 ºC followed by densification) were studied at three temperatures (500, 600, 700 ºC) using a pyroprobe attached to a gas chromatogram mass spectroscopy (Py-GC/MS). The torrefaction of switchgrass improved its oxygen to carbon ratio and energy content. Contents of anhydrous sugars and phenols in pyrolysis products of torrefied switchgrass were higher than those in pyrolysis products of raw switchgrass. As the torrefaction temperature increased from 230 to 270 °C, the contents of anhydrous sugars and phenols in pyrolysis productsmore » increased whereas content of guaiacols decreased. High pyrolysis temperature (600 and 700 °C as compared to 500 °C) enhanced decomposition of lignin and anhydrous sugars, leading to increase in phenols, aromatics and furans. Densification enhanced depolymerization of cellulose and hemicellulose during pyrolysis.« less

Consolidated bioprocessing of transgenic switchgrass by an engineered and evolved Clostridium thermocellum strain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, Kelsey L; Rodriguez Jr, Miguel; Thompson, Olivia A

Background: Switchgrass is an abundant and dedicated bioenergy feedstock however its inherent recalcitrance is one of the economic hurdles for producing biofuels. The down-regulation of the caffeic acid O-methyl transferase (COMT) gene in the lignin pathway of switchgrass reduced lignin content and S/G ratio, and the transgenic lines showed improved fermentation yield with S. cerevisiae and C. thermocellum (ATCC 27405) in comparison to the wild-type switchgrass. Results: Here we examine the fermentation potential of the COMT transgenic switchgrass and its wild-type line, with an engineered and evolved Clostridium thermocellum (M1570) strain. The fermentation of the transgenic switchgrass had superior conversionmore » relative to the control line with an increase of 20% and ethanol was the primary metabolite accounting for 90% of the total metabolites measured by HPLC. Conclusions: The down-regulation of the COMT gene in switchgrass reduced recalcitrance and improved microbial bioconversion yield. Moreover, these results showed ethanol as the main fermentation metabolite produced by an engineered and evolved C. thermocellum strain grown on a transgenic switchgrass.« less

76 FR 18581 - Correction; Central Valley Project Improvement Act, Standard Criteria for Agricultural and Urban...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Correction; Central Valley Project Improvement Act, Standard Criteria for Agricultural and Urban Water Management Plans AGENCY: Bureau of Reclamation... notice in the Federal Register at 76 FR 16818 on the Central Valley Project Improvement Act Standard...

AmeriFlux US-AR2 ARM USDA UNL OSU Woodward Switchgrass 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Billesbach, Dave; Bradford, James

This is the AmeriFlux version of the carbon flux data for the site US-AR2 ARM USDA UNL OSU Woodward Switchgrass 2. Site Description - The ARM USDA UNL OSU Woodward Switchgrass 2 tower is located on public land owned by the USDA-ARS Southern Plains Range Research Station in Woodward, Oklahoma. The site is on a former wheat field that is in the process of changing to switchgrass. A companion site (ARM USDA UNL OSU Woodward Switchgrass 1) is on a former native prairie. Previous wheat was planted in Fall 2008. In Spring 2009, herbicide was applied to kill the wheatmore » prior to switchgrass planting. Later in the year, the site was sprayed with post-emergence herbicide. In 2010, fertilization occurred before herbicide was sprayed for broadleaf control.« less

Comparative study of switchgrass cultivars using RNA sequencing technology

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a C4 perennial grass, identified as a promising bioenergy crop. Switchgrass exists in two ecotypes, upland and lowland, which are heterotic, or genetically complementary to each other. The objectives of this study are to assess the potential of SNP markers as a b...

75 FR 62853 - Notice of Availability of the Record of Decision for the Imperial Valley Solar Project and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-13

..., LVRAB109AA01] Notice of Availability of the Record of Decision for the Imperial Valley Solar Project and...) application CACA-47740 for the proposed SES Solar Two Project. After merging with Tessera Solar, the applicant changed its name to Imperial Valley Solar, LLC, and changed the name of the project to the Imperial Valley...

Alteration of S-adenosylhomocysteine levels affects lignin biosynthesis in switchgrass.

PubMed

Bai, Zetao; Qi, Tianxiong; Liu, Yuchen; Wu, Zhenying; Ma, Lichao; Liu, Wenwen; Cao, Yingping; Bao, Yan; Fu, Chunxiang

2018-04-28

Methionine (Met) synthesized from aspartate is a fundamental amino acid needed to produce S-adenosylmethionine (SAM) that is an important cofactor for the methylation of monolignols. As a competitive inhibitor of SAM-dependent methylation, the effect of S-adenosylhomocysteine (SAH) on lignin biosynthesis, however, is still largely unknown in plants. Expression levels of Cystathionine γ-synthase (PvCGS) and S-adenosylhomocysteine hydrolase1 (PvSAHH1) were downregulated by RNAi technology, respectively, in switchgrass, a dual-purpose forage and biofuel crop. The transgenic switchgrass lines were subjected to studying the impact of SAH on lignin biosynthesis. Our results showed that downregulation of PvCGS in switchgrass altered the accumulation of aspartate-derived and aromatic amino acids, reduced the content of SAH, enhanced lignin biosynthesis, and stunted plant growth. In contrast, downregulation of PvSAHH1 raised SAH levels in switchgrass, impaired the biosynthesis of both guaiacyl and syringyl lignins, and therefore significantly increased saccharification efficiency of cell walls. This work indicates that SAH plays a crucial role in monolignol methylation in switchgrass. Genetic regulation of either PvCGS or PvSAHH1 expression in switchgrass can change intracellular SAH contents and SAM to SAH ratios and therefore affect lignin biosynthesis. Thus, our study suggests that genes involved in Met metabolism are of interest as new valuable targets for cell wall bioengineering in future. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

77 FR 33240 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... Project water conservation best management practices that shall ``develop criteria for evaluating the... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The...

76 FR 16818 - Central Valley Project Improvement Act, Standard Criteria for Ag and Urban Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-25

... Valley Project water conservation best management practices (BMPs) that shall develop Criteria for... project contractors using best available cost- effective technology and best management practices.'' The... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Standard...

Transcriptome Profiling of Rust Resistance in Switchgrass Using RNA-Seq Analysis

DOE PAGES

Serba, Desalegn D.; Uppalapati, Srinivasa Rao; Mukherjee, Shreyartha; ...

2015-03-16

Switchgrass rust caused by Puccinia emaculata is a major limiting factor for switchgrass (Panicum virgatum L.) production, especially in monoculture. Natural populations of switchgrass displayed diverse reactions to P. emaculata when evaluated in an Ardmore, OK, field. In order to identify the differentially expressed genes during the rust infection process and the mechanisms of switchgrass rust resistance, transcriptome analysis using RNA-Seq was conducted in two pseudo-F 1 parents ('PV281' and 'NFGA472'), and three moderately resistant and three susceptible progenies selected from a three-generation, four-founder switchgrass population (K5 x A4) x (AP13 x VS16). On average, 23.5 million reads per samplemore » (leaf tissue was collected at 0, 24, and 60 h post-inoculation (hpi)) were obtained from paired-end (2 x 100 bp) sequencing on the Illumina HiSeq2000 platform. Furthermore, mapping of the RNA-Seq reads to the switchgrass reference genome (AP13 ver. 1.1 assembly) constructed a total of 84,209 transcripts from 98,007 gene loci among all of the samples. Further analysis revealed that host defense- related genes, including the nucleotide binding site-leucinerich repeat domain containing disease resistance gene analogs, play an important role in resistance to rust infection. Rust-induced gene (RIG) transcripts inherited across generations were identified. The rust-resistant gene transcripts can be a valuable resource for developing molecular markers for rust resistance. Finally we identified the rust-resistant genotypes and gene transcripts which can expedite rust-resistant cultivar development in switchgrass.« less

Transcriptome Profiling of Rust Resistance in Switchgrass Using RNA-Seq Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serba, Desalegn D.; Uppalapati, Srinivasa Rao; Mukherjee, Shreyartha

Switchgrass rust caused by Puccinia emaculata is a major limiting factor for switchgrass (Panicum virgatum L.) production, especially in monoculture. Natural populations of switchgrass displayed diverse reactions to P. emaculata when evaluated in an Ardmore, OK, field. In order to identify the differentially expressed genes during the rust infection process and the mechanisms of switchgrass rust resistance, transcriptome analysis using RNA-Seq was conducted in two pseudo-F 1 parents ('PV281' and 'NFGA472'), and three moderately resistant and three susceptible progenies selected from a three-generation, four-founder switchgrass population (K5 x A4) x (AP13 x VS16). On average, 23.5 million reads per samplemore » (leaf tissue was collected at 0, 24, and 60 h post-inoculation (hpi)) were obtained from paired-end (2 x 100 bp) sequencing on the Illumina HiSeq2000 platform. Furthermore, mapping of the RNA-Seq reads to the switchgrass reference genome (AP13 ver. 1.1 assembly) constructed a total of 84,209 transcripts from 98,007 gene loci among all of the samples. Further analysis revealed that host defense- related genes, including the nucleotide binding site-leucinerich repeat domain containing disease resistance gene analogs, play an important role in resistance to rust infection. Rust-induced gene (RIG) transcripts inherited across generations were identified. The rust-resistant gene transcripts can be a valuable resource for developing molecular markers for rust resistance. Finally we identified the rust-resistant genotypes and gene transcripts which can expedite rust-resistant cultivar development in switchgrass.« less

78 FR 63491 - Central Valley Project Improvement Act, Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-24

... Valley Project Improvement Act, Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The following Water Management Plans are available for review: Westside... project contractors using best available cost-effective technology and best management practices.'' These...

The application of ultrasound in the enzymatic hydrolysis of switchgrass

USDA-ARS?s Scientific Manuscript database

In a series of experiments, untreated and ammonium hydroxide pretreated Klenow lowland variety switchgrasses are converted to reducing sugars using low frequency (20 kHz) ultrasound and commercially-available cellulase enzyme. Results from experiments using untreated and pretreated switchgrasses wit...

Genetic manipulation of lignin reduces recalcitrance and improves ethanol production from switchgrass

PubMed Central

Fu, Chunxiang; Mielenz, Jonathan R.; Xiao, Xirong; Ge, Yaxin; Hamilton, Choo Y.; Rodriguez, Miguel; Chen, Fang; Foston, Marcus; Ragauskas, Arthur; Bouton, Joseph; Dixon, Richard A.; Wang, Zeng-Yu

2011-01-01

Switchgrass is a leading dedicated bioenergy feedstock in the United States because it is a native, high-yielding, perennial prairie grass with a broad cultivation range and low agronomic input requirements. Biomass conversion research has developed processes for production of ethanol and other biofuels, but they remain costly primarily because of the intrinsic recalcitrance of biomass. We show here that genetic modification of switchgrass can produce phenotypically normal plants that have reduced thermal-chemical (≤180 °C), enzymatic, and microbial recalcitrance. Down-regulation of the switchgrass caffeic acid O-methyltransferase gene decreases lignin content modestly, reduces the syringyl:guaiacyl lignin monomer ratio, improves forage quality, and, most importantly, increases the ethanol yield by up to 38% using conventional biomass fermentation processes. The down-regulated lines require less severe pretreatment and 300–400% lower cellulase dosages for equivalent product yields using simultaneous saccharification and fermentation with yeast. Furthermore, fermentation of diluted acid-pretreated transgenic switchgrass using Clostridium thermocellum with no added enzymes showed better product yields than obtained with unmodified switchgrass. Therefore, this apparent reduction in the recalcitrance of transgenic switchgrass has the potential to lower processing costs for biomass fermentation-derived fuels and chemicals significantly. Alternatively, such modified transgenic switchgrass lines should yield significantly more fermentation chemicals per hectare under identical process conditions. PMID:21321194

77 FR 18858 - Remanded Biological Opinions on the Coordinated Long-Term Operation of the Central Valley Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

... Long-Term Operation of the Central Valley Project and State Water Project: Notice of Intent To Prepare... Central Valley Project, in a coordinated manner with the State Water Project, that are likely to avoid... Department of Water Resources, California Department of Fish and Game, State and Federal Contractors Water...

Kinetics of methane production from the codigestion of switchgrass and Spirulina platensis algae.

PubMed

El-Mashad, Hamed M

2013-03-01

Anaerobic batch digestion of four feedstocks was conducted at 35 and 50 °C: switchgrass; Spirulina platensis algae; and two mixtures of both switchgrass and S. platensis. Mixture 1 was composed of 87% switchgrass (based on volatile solids) and 13% S. platensis. Mixture 2 was composed of 67% switchgrass and 33% S. platensis. The kinetics of methane production from these feedstocks was studied using four first order models: exponential, Gompertz, Fitzhugh, and Cone. The methane yields after 40days of digestion at 35 °C were 355, 127, 143 and 198 ml/g VS, respectively for S. platensis, switchgrass, and Mixtures 1 and 2, while the yields at 50 °C were 358, 167, 198, and 236 ml/g VS, respectively. Based on Akaike's information criterion, the Cone model best described the experimental data. The Cone model was validated with experimental data collected from the digestion of a third mixture that was composed of 83% switchgrass and 17% S. platensis. Published by Elsevier Ltd.

Anthracnose disease of switchgrass caused by the novel fungal species Colletotrichum navitas.

PubMed

Crouch, Jo Anne; Beirn, Lisa A; Cortese, Laura M; Bonos, Stacy A; Clarke, Bruce B

2009-12-01

In recent years perennial grasses such as the native tallgrass prairie plant Panicum virgatum (switchgrass) have taken on a new role in the North American landscape as a plant-based source of renewable energy. Because switchgrass is a native plant, it has been suggested that disease problems will be minimal, but little research in this area has been conducted. Recently, outbreaks of switchgrass anthracnose disease have been reported from the northeastern United States. Incidences of switchgrass anthracnose are known in North America since 1886 through herbarium specimens and disease reports, but the causal agent of this disease has never been experimentally determined or taxonomically evaluated. In the present work, we evaluate the causal agent of switchgrass anthracnose, a new species we describe as Colletotrichum navitas (navitas=Latin for energy). Multilocus molecular phylogenetics and morphological characters show C. navitas is a novel species in the falcate-spored graminicolous group of the genus Colletotrichum; it is most closely related to the corn anthracnose pathogen Colletotrichum graminicola. We present a formal description and illustrations for C. navitas and provide experimental confirmation that this organism is responsible for switchgrass anthracnose disease.

The Pleasant Valley School: A Living History Project

ERIC Educational Resources Information Center

Buckner, David L.; Brown, Pamela U.; Curry, John

2010-01-01

This article discusses the Pleasant Valley School, located in Stillwater, Oklahoma, which is now a living history project where contemporary 4th grade students throughout Oklahoma have the opportunity to spend a day as students did in a turn of the century one-room schoolhouse, complete with coal heating, ink wells, and "McGuffey…

Characterization of Brachypodium distachyon as a nonhost model against switchgrass rust pathogen Puccinia emaculata.

PubMed

Gill, Upinder S; Uppalapati, Srinivasa R; Nakashima, Jin; Mysore, Kirankumar S

2015-05-08

Switchgrass rust, caused by Puccinia emaculata, is an important disease of switchgrass, a potential biofuel crop in the United States. In severe cases, switchgrass rust has the potential to significantly affect biomass yield. In an effort to identify novel sources of resistance against switchgrass rust, we explored nonhost resistance against P. emaculata by characterizing its interactions with six monocot nonhost plant species. We also studied the genetic variations for resistance among Brachypodium inbred accessions and the involvement of various defense pathways in nonhost resistance of Brachypodium. We characterized P. emaculata interactions with six monocot nonhost species and identified Brachypodium distachyon (Bd21) as a suitable nonhost model to study switchgrass rust. Interestingly, screening of Brachypodium accessions identified natural variations in resistance to switchgrass rust. Brachypodium inbred accessions Bd3-1 and Bd30-1 were identified as most and least resistant to switchgrass rust, respectively, when compared to tested accessions. Transcript profiling of defense-related genes indicated that the genes which were induced in Bd21after P. emaculata inoculation also had higher basal transcript abundance in Bd3-1 when compared to Bd30-1 and Bd21 indicating their potential involvement in nonhost resistance against switchgrass rust. In the present study, we identified Brachypodium as a suitable nonhost model to study switchgrass rust which exhibit type I nonhost resistance. Variations in resistance response were also observed among tested Brachypodium accessions. Brachypodium nonhost resistance against P. emaculata may involve various defense pathways as indicated by transcript profiling of defense related genes. Overall, this study provides a new avenue to utilize novel sources of nonhost resistance in Brachypodium against switchgrass rust.

Soil carbon dynamics beneath switchgrass as indicated by stable isotope analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, C.T. Jr.; Wullschleger, S.D.

2000-04-01

Surface (0--40 cm) soil organic carbon (SOC) dynamics were studied beneath four switchgrass (Panicum virgatum L.) field trails in the southeastern US. Soil organic carbon was partitioned into particulate organic matter (POM) and mineral-associated organic matter (MOM). Most (75--90%) of the SOC at each study site was affiliated with MOM (<0.053 mm). Changes in stable carbon isotope ratios were used to derive carbon inputs to and losses from POM and MOM at each site. Inventories of existing SOC and new C{sub 4}-derived SOC beneath switchgrass decreased with increasing soil depth. Approximately 5 yr after establishment, 19 to 31% of themore » existing SOC inventories beneath switchgrass had been derived from new C{sub 4}-carbon inputs. Calculated turnover times of POM and MOM ranged from 2.4 to 4.3 yr and 26 to 40 yr, respectively. The turnover time of SOC in the POM fraction increased with decreasing mean annual temperature. A simple, two-compartment model was parameterized to predict the potential for soil carbon sequestration under switchgrass. An example calculation with the model indicated a measurable and verifiable recovery of soil carbon (=12% increase) on degraded lands through one decade of switchgrass production. The potential to sequester carbon through switchgrass cultivation will depend on initial soil carbon inventories, prevailing climate, soil types and site management.« less

Soil carbon dynamics beneath switchgrass as indicated by stable isotope analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten Jr, Charles T; Wullschleger, Stan D

2000-04-01

Surface (0-40 cm) soil organic carbon (SOC) dynamics were studied beneath four switchgrass (Panicum virgatum L.) field trials in the southeastern United States. Soil organic carbon was partitioned into particulate organic matter (POM) and mineral-associated organic matter (MOM). Most (75-90%) of the SOC at each study site was affiliated with MOM (<0.053 mm). Changes in stable carbon isotope ratios were used to derive carbon inputs to and losses from POM and MOM at each site. Inventories of existing SOC and new C4-derived SOC beneath switchgrass decreased with increasing soil depth. Approximately 5 yr after establishment, 19 to 31% of themore » existing SOC inventories beneath switchgrass had been derived from new C{sub 4}-carbon inputs. Calculated turnover times of POM and MOM ranged from 2.4 to 4.3 yr and 26 to 40 yr, respectively. The turnover time of SOC in the POM fraction increased with decreasing mean annual temperature. A simple, two-compartment model was parameterized to predict the potential for soil carbon sequestration under switchgrass. An example calculation with the model indicated a measurable and verifiable recovery of soil carbon ({approx}12% increase) on degraded lands through one decade of switchgrass production. The potential to sequester carbon through switchgrass cultivation will depend on initial soil carbon inventories, prevailing climate, soil type, and site management.« less

Natural hybrids and gene flow between upland and lowland switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a perennial grass native to the North American tallgrass prairie and savanna habitats and is broadly adapted to the central and eastern USA. Upland and lowland ecotypes represent the two major taxa within switchgrass, which have distinct, but overlapping distribu...

Soil and variety effects on the energy and carbon balances of switchgrass-derived ethanol

USDA-ARS?s Scientific Manuscript database

This study examined the effects of soil and switchgrass variety on sustainability and eco-friendliness of switchgrass-based ethanol production. Using the Agricultural Land Management Alternatives with Numerical Assessment Criteria (ALMANAC) model, switchgrass biomass yields were simulated for severa...

Life cycle assessment of switchgrass- and corn stover-derived ethanol-fueled automobiles.

PubMed

Spatari, Sabrina; Zhang, Yimin; MacLean, Heather L

2005-12-15

Utilizing domestically produced cellulose-derived ethanol for the light-duty vehicle fleet can potentially improve the environmental performance and sustainability of the transport and energy sectors of the economy. A life cycle assessment model was developed to examine environmental implications of the production and use of ethanol in automobiles in Ontario, Canada. The results were compared to those of low-sulfur reformulated gasoline (RFG) in a functionally equivalent automobile. Two time frames were evaluated, one near-term (2010), which examines converting a dedicated energy crop (switchgrass) and an agricultural residue (corn stover) to ethanol; and one midterm (2020), which assumes technological improvements in the switchgrass-derived ethanol life cycle. Near-term results show that, compared to a RFG automobile, life cycle greenhouse gas (GHG) emissions are 57% lower for an E85-fueled automobile derived from switchgrass and 65% lower for ethanol from corn stover, on a grams of CO2 equivalent per kilometer basis. Corn stover ethanol exhibits slightly lower life cycle GHG emissions, primarily due to sharing emissions with grain production. Through projected improvements in crop and ethanol yields, results for the mid-term scenario show that GHG emissions could be 25-35% lower than those in 2010 and that, even with anticipated improvements in RFG automobiles, E85 automobiles could still achieve up to 70% lower GHG emissions across the life cycle.

AmeriFlux US-AR1 ARM USDA UNL OSU Woodward Switchgrass 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Billesbach, Dave; Bradford, James

This is the AmeriFlux version of the carbon flux data for the site US-AR1 ARM USDA UNL OSU Woodward Switchgrass 1. Site Description - The ARM USDA UNL OSU Woodward Switchgrass 1 tower is located on public land owned by the USDA-ARS Southern Plains Range Research Station in Woodward, Oklahoma. The site is on a former native prairie that is in the process of changing to switchgrass. A second companion site (ARM USDA UNL OSU Woodward Switchgrass 2) is on a former wheat field. In Spring 2009, the former native prairie site was burned, cattle were put on the pasturemore » to graze down emergent grass, and broadleaf herbicide was sprayed. In Summer 2009, the cattle were removed from the pasture, and the site was sprayed with herbicide to kill all grass. In Spring 2010, prior to the planting of switchgrass, final herbicide was sprayed to kill cheat grass and to control broadleaf plants.« less

Switchgrass and pecan biochar amendments to a sandy coastal soil

USDA-ARS?s Scientific Manuscript database

Sandy soils of the wet, warm SE Coastal Plain have poor physical characteristics and low carbon contents. To improve soil properties, we added switchgrass (Panicum virgatum) and non-activated pecan (Carya illinoinensis) biochar. Switchgrass was ground to a fine powder and added to soil at rates of 0...

Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

NASA Astrophysics Data System (ADS)

Slavens, Shelyn Gehle

Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

Breeding and Selection of New Switchgrass Varieties for Increased Biomass Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taliaferro, C.M.

2003-05-27

Switchgrass breeding and genetics research was conducted from 1992-2002 at the Oklahoma State University as part of the national DOE-Bioenergy Feedstock Development Program (BFDP) effort to develop the species as a bioenergy feedstock crop. The fundamental objective of the program was to implement and conduct a breeding program to increase biomass yield capability in switchgrass and develop cultivars for the central and southern United States. Supporting research objectives included: (1) switchgrass germplasm collection, characterization, and enhancement; (2) elucidation of cytogenetic and breeding behavior; and (3) identification of best breeding procedures.

Generation of Neo Octaploid Switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) exists as multiple cytotypes with octaploid and tetraploid populations occupying distinct, overlapping ranges. These cytotypes tend to show differences in adaptation, yield potential, and other characters, but the specific result of whole genome duplication is not ...

Short-term bird response to harvesting switchgrass for biomass in Iowa

USGS Publications Warehouse

Murray, L.D.; Best, Louis B.

2003-01-01

The Conservation Reserve Program (CRP) provides habitat for grassland birds, but as contracts expire, some CRP fields might be returned to rowcrop production. One alternative to returning CRP fields to rowcrops is to produce switchgrass (Panicum virgatum) for use as a biomass fuel. Because the biomass is harvested during the fall and winter, breeding birds would not be directly affected by mowing the fields bur might be influenced by changes in vegetation structure resulting from the harvest. We evaluated bird abundances and nest success in totally harvested, partially harvested (alternating cut and uncut strips), and nonharvested CRP switchgrass fields in southern Iowa, USA, in 1999 and 2000. Species richness did not differ among harvest treatments. Abundances of most species (16 of 18) were not affected by the harvesting of switchgrass fields, and strip width did not affect bird numbers in strip-harvested fields. Grasshopper sparrows (Ammodramus savannarum) were more abundant in harvested portions of fields, and more sedge wrens (Cistothorus platensis) were recorded in nonharvested areas. The residual vegetation in nonharvested areas provided nest cover for species that begin nesting early in the season (e.g., northern harrier [Circus cyaneus] and ring-necked pheasant [Phasianus colchicus]). Nest success rates of grasshopper sparrows and common yellowthroats (Geothlypis trichas) were similar to those reported by other studies in switchgrass fields and might be sufficient to maintain stable populations. In general, switchgrass biomass fields create breeding habitat for some grassland birds, and a mixture of harvested and nonharvested fields would be more beneficial to grassland birds than totally harvesting or partially harvesting all switchgrass fields.

Transgene autoexcision in switchgrass pollen mediated by the Bxb1 recombinase

PubMed Central

2014-01-01

Background Switchgrass (Panicum virgatum L.) has a great potential as a platform for the production of biobased plastics, chemicals and energy mainly because of its high biomass yield on marginal land and low agricultural inputs. During the last decade, there has been increased interest in the genetic improvement of this crop through transgenic approaches. Since switchgrass, like most perennial grasses, is exclusively cross pollinating and poorly domesticated, preventing the dispersal of transgenic pollen into the environment is a critical requisite for the commercial deployment of this important biomass crop. In this study, the feasibility of controlling pollen-mediated gene flow in transgenic switchgrass using the large serine site-specific recombinase Bxb1 has been investigated. Results A novel approach utilizing co-transformation of two separate vectors was used to test the functionality of the Bxb1/att recombination system in switchgrass. In addition, two promoters with high pollen-specific activity were identified and thoroughly characterized prior to their introduction into a test vector explicitly designed for both autoexcision and quantitative analyses of recombination events. Our strategy for developmentally programmed precise excision of the recombinase and marker genes in switchgrass pollen resulted in the generation of transgene-excised progeny. The autoexcision efficiencies were in the range of 22-42% depending on the transformation event and assay used. Conclusion The results presented here mark an important milestone towards the establishment of a reliable biocontainment system for switchgrass which will facilitate the development of this crop as a biorefinery feedstock through advanced biotechnological approaches. PMID:25148894

Identification and Characterization of Switchgrass Histone H3 and CENH3 Genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, Jiamin; Frazier, Taylor; Huang, Linkai

Switchgrass is one of the most promising energy crops and only recently has been employed for biofuel production. The draft genome of switchgrass was recently released; however, relatively few switchgrass genes have been functionally characterized. CENH3, the major histone protein found in centromeres, along with canonical H3 and other histones, plays an important role in maintaining genome stability and integrity. Despite their importance, the histone H3 genes of switchgrass have remained largely uninvestigated. In this study, we identified 17 putative switchgrass histone H3 genes in silico. Of these genes, 15 showed strong homology to histone H3 genes including six H3.1more » genes, three H3.3 genes, four H3.3-like genes and two H3.1-like genes. The remaining two genes were found to be homologous to CENH3. RNA-seq data derived from lowland cultivar Alamo and upland cultivar Dacotah allowed us to identify SNPs in the histone H3 genes and compare their differential gene expression. Interestingly, we also found that overexpression of switchgrass histone H3 and CENH3 genes in N. benthamiana could trigger cell death of the transformed plant cells. Localization and deletion analyses of the histone H3 and CENH3 genes revealed that nuclear localization of the N-terminal tail is essential and sufficient for triggering the cell death phenotype. Lastly, our results deliver insight into the mechanisms underlying the histone-triggered cell death phenotype and provide a foundation for further studying the variations of the histone H3 and CENH3 genes in switchgrass.« less

Identification and Characterization of Switchgrass Histone H3 and CENH3 Genes

DOE PAGES

Miao, Jiamin; Frazier, Taylor; Huang, Linkai; ...

2016-07-12

Switchgrass is one of the most promising energy crops and only recently has been employed for biofuel production. The draft genome of switchgrass was recently released; however, relatively few switchgrass genes have been functionally characterized. CENH3, the major histone protein found in centromeres, along with canonical H3 and other histones, plays an important role in maintaining genome stability and integrity. Despite their importance, the histone H3 genes of switchgrass have remained largely uninvestigated. In this study, we identified 17 putative switchgrass histone H3 genes in silico. Of these genes, 15 showed strong homology to histone H3 genes including six H3.1more » genes, three H3.3 genes, four H3.3-like genes and two H3.1-like genes. The remaining two genes were found to be homologous to CENH3. RNA-seq data derived from lowland cultivar Alamo and upland cultivar Dacotah allowed us to identify SNPs in the histone H3 genes and compare their differential gene expression. Interestingly, we also found that overexpression of switchgrass histone H3 and CENH3 genes in N. benthamiana could trigger cell death of the transformed plant cells. Localization and deletion analyses of the histone H3 and CENH3 genes revealed that nuclear localization of the N-terminal tail is essential and sufficient for triggering the cell death phenotype. Lastly, our results deliver insight into the mechanisms underlying the histone-triggered cell death phenotype and provide a foundation for further studying the variations of the histone H3 and CENH3 genes in switchgrass.« less

Switchgrass potential on reclaimed surface mines for biofuel production in West Virginia

NASA Astrophysics Data System (ADS)

Marra, Michael A.

The high cost and environmental risks associated with non-renewable energy sources has caused an increased interest in, and development of renewable biofuels. Switchgrass (Panicum virgatum L.), a warm season perennial grass, has been investigated as a source of biofuel feedstock due to its high biomass production on marginal soils, its tolerance of harsh growing conditions, and its ability to provide habitat for wildlife and soil conservation cover. West Virginia contains vast expanses of reclaimed surface mine lands and could potentially benefit from the production of switchgrass as a biofuel feedstock. Furthermore, switchgrass production could satisfy Surface Mining Reclamation and Control Act of 1977 (SMCRA) requirements for reclamation bond release to mine operators. Three separate studies will be discussed in this thesis to determine if switchgrass grown on reclaimed surface mines can produce yields similar to yields from stands grown under normal agronomic conditions and what common surface mining reclamation practices may be most appropriate for growing switchgrass. The first study examined yield production of three commercially-available, upland switchgrass varieties grown on two reclaimed surface mines in production years two, three and four. The Hampshire Hill mine site, which was reclaimed in the late 1990s using top soil and treated municipal sludge, averaged 5,800 kg (ha-yr)-1 of switchgrass compared to 803 kg (ha-yr)-1 at the Hobet 21 site which was reclaimed with crushed, unweathered rock over compacted overburden. Site and variety interacted with Cave-in-Rock as the top performer at the more fertile Hampshire Hill site and Shawnee produced the highest yields at Hobet 21 (7,853 kg ha-1 and 1,086 kg ha-1 averaged across years, respectively). Switchgrass yields increased from 2009 to 2010, but declined from 2010 to 2011. Switchgrass yields from farmlands in this region averaged about 15000 kg (ha-yr)-1 in the research literature, so switchgrass grown

Switchgrass harvest time management can impact biomass yield and nutrient content

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a dedicated energy crop native to much of North America. While high-biomass yield is of significant importance for the development of switchgrass as a bioenergy crop, nutrient content in the biomass as it relates to biofuel conversion efficiency is also critical...

Switchgrass cultivars alter microbial contribution to deep soil C in Nebraska

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland) and cultivars, there has been little focus on the impact of plant belowgro...

Environmental and economic analysis of switchgrass production for water quality improvement in northeast Kansas.

PubMed

Nelson, Richard G; Ascough, James C; Langemeier, Michael R

2006-06-01

The primary objectives of this research were to determine SWAT model predicted reductions in four water quality indicators (sediment yield, surface runoff, nitrate nitrogen (NO(3)-N) in surface runoff, and edge-of-field erosion) associated with producing switchgrass (Panicum virgatum) on cropland in the Delaware basin in northeast Kansas, and evaluate switchgrass break-even prices. The magnitude of potential switchgrass water quality payments based on using switchgrass as an alternative energy source was also estimated. SWAT model simulations showed that between 527,000 and 1.27 million metric tons (Mg) of switchgrass could be produced annually across the basin depending upon nitrogen (N) fertilizer application levels (0-224 kg N ha(-1)). The predicted reductions in sediment yield, surface runoff, NO(3)-N in surface runoff, and edge-of-field erosion as a result of switchgrass plantings were 99, 55, 34, and 98%, respectively. The average annual cost per hectare for switchgrass ranged from about 190 US dollars with no N applied to around 345 US dollars at 224 kg N ha(-1) applied. Edge-of-field break-even price per Mg ranged from around 41 US dollars with no N applied to slightly less than 25 US dollars at 224 kg N ha(-1) applied. A majority of the switchgrass produced had an edge-of-field break-even price of 30 Mg(-1) US dollars or less. Savings of at least 50% in each of the four water quality indicators could be attained for an edge-of-field break-even price of 22-27.49 US dollars Mg(-1).

A model for deploying switchgrass for bioenergy in an intensive agricultural landscape

USDA-ARS?s Scientific Manuscript database

Switchgrass bioenergy research has been conducted in Nebraska since 1990. In that time, significant progress has been made in switchgrass breeding and genetics, molecular genetics, establishment, fertility management, production economics, production energetics, harvest and storage management, ecos...

The effect of switchgrass loadings on feedstock solubilization and biofuel production by Clostridium thermocellum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verbeke, Tobin J.; Garcia, Gabriela M.; Elkins, James G.

High solids loading fermentations are necessary for the industrialization of lignocellulosic ethanol. To date, only a few studies have investigated the effect of solids loadings on microorganisms of interest for consolidated bioprocessing (CBP). Here, the effect that various switchgrass loadings have on Clostridium thermocellum solubilization and bioconversion are investigated. C. thermocellum was grown for ten days on 10, 25 or 50 g/L switchgrass or Avicel at equivalent glucan loadings. Avicel was completely consumed at all loadings, but total cellulose solubilization decreased from 63% to 37% as switchgrass loadings increased from 10 g/L to 50 g/L. Washed, spent switchgrass could bemore » additionally hydrolyzed and fermented in second-round fermentations suggesting access to fermentable substrates was not the limiting factor at higher feedstock loadings. Fermentations of Avicel or cellobiose using culture medium supplemented with 50% spent fermentation broth identified that compounds present in the samples collected from the 25 or 50 g/L switchgrass loadings were the most inhibitory to continued fermentation. Finally, recalcitrance alone cannot fully account for differences in solubilization and end-production formation between switchgrass and Avicel at increased substrate loadings. Effort to decouple metabolic inhibition from inhibition of hydrolysis suggest that C. thermocellum’s hydrolytic machinery is more vulnerable to inhibition from switchgrass-derived inhibitors than is the bacterium’s metabolism.« less

The effect of switchgrass loadings on feedstock solubilization and biofuel production by Clostridium thermocellum

DOE PAGES

Verbeke, Tobin J.; Garcia, Gabriela M.; Elkins, James G.

2017-11-30

High solids loading fermentations are necessary for the industrialization of lignocellulosic ethanol. To date, only a few studies have investigated the effect of solids loadings on microorganisms of interest for consolidated bioprocessing (CBP). Here, the effect that various switchgrass loadings have on Clostridium thermocellum solubilization and bioconversion are investigated. C. thermocellum was grown for ten days on 10, 25 or 50 g/L switchgrass or Avicel at equivalent glucan loadings. Avicel was completely consumed at all loadings, but total cellulose solubilization decreased from 63% to 37% as switchgrass loadings increased from 10 g/L to 50 g/L. Washed, spent switchgrass could bemore » additionally hydrolyzed and fermented in second-round fermentations suggesting access to fermentable substrates was not the limiting factor at higher feedstock loadings. Fermentations of Avicel or cellobiose using culture medium supplemented with 50% spent fermentation broth identified that compounds present in the samples collected from the 25 or 50 g/L switchgrass loadings were the most inhibitory to continued fermentation. Finally, recalcitrance alone cannot fully account for differences in solubilization and end-production formation between switchgrass and Avicel at increased substrate loadings. Effort to decouple metabolic inhibition from inhibition of hydrolysis suggest that C. thermocellum’s hydrolytic machinery is more vulnerable to inhibition from switchgrass-derived inhibitors than is the bacterium’s metabolism.« less

"U.S.R.S., Grand Valley Project, Colo. Sprocket, shaft and chain for ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

"U.S.R.S., Grand Valley Project, Colo. Sprocket, shaft and chain for 70 ft. roller hoist. May 14, 1915." Note that on this and other working drawings of the roller gates, the German manufacturer/patent holder is not acknowledged - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

PubMed

Jin, Guang; Bierma, Tom; Walker, Paul M

2014-01-01

This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

Silicon cantilever functionalization for cellulose-specific chemical force imaging of switchgrass

DOE PAGES

Lee, Ida; Evans, Barbara R.; Foston, Marcus B.; ...

2015-05-08

A method for direct functionalization of silicon and silicon nitride cantilevers with bifunctional silanes was tested with model surfaces to determine adhesive forces for different hydrogen-bonding chemistries. Application for biomass surface characterization was tested by mapping switchgrass and isolated switchgrass cellulose in topographic and force-volume mode using a cellulose-specific cantilever.

Overexpression of AtLOV1 in Switchgrass alters plant architecture, lignin content, and flowering time.

PubMed

Xu, Bin; Sathitsuksanoh, Noppadon; Tang, Yuhong; Udvardi, Michael K; Zhang, Ji-Yi; Shen, Zhengxing; Balota, Maria; Harich, Kim; Zhang, Percival Y-H; Zhao, Bingyu

2012-01-01

Switchgrass (Panicum virgatum L.) is a prime candidate crop for biofuel feedstock production in the United States. As it is a self-incompatible polyploid perennial species, breeding elite and stable switchgrass cultivars with traditional breeding methods is very challenging. Translational genomics may contribute significantly to the genetic improvement of switchgrass, especially for the incorporation of elite traits that are absent in natural switchgrass populations. In this study, we constitutively expressed an Arabidopsis NAC transcriptional factor gene, LONG VEGETATIVE PHASE ONE (AtLOV1), in switchgrass. Overexpression of AtLOV1 in switchgrass caused the plants to have a smaller leaf angle by changing the morphology and organization of epidermal cells in the leaf collar region. Also, overexpression of AtLOV1 altered the lignin content and the monolignol composition of cell walls, and caused delayed flowering time. Global gene-expression analysis of the transgenic plants revealed an array of responding genes with predicted functions in plant development, cell wall biosynthesis, and flowering. To our knowledge, this is the first report of a single ectopically expressed transcription factor altering the leaf angle, cell wall composition, and flowering time of switchgrass, therefore demonstrating the potential advantage of translational genomics for the genetic improvement of this crop.

Selecting, Establishing, and Managing Switchgrass (Panicum virgatum) for Biofuels

NASA Astrophysics Data System (ADS)

Parrish, David J.; Fike, John H.

Switchgrass is being widely considered as a feedstock for biofuel production. Much remains to be learned about ideal feedstock characteristics, but switchgrass offers many advantages already and can perhaps be manipulated to offer more. When planning to grow switchgrass, select a cultivar that is well adapted to the location - generally a lowland cultivar for the southern United States and an upland cultivar at higher latitudes. Plant non-dormant seed after soils are well warmed, preferably with no-till methods and always with good weed control. Except for weeds, few pests appear to be widespread; but disease and insect pests could become more important as acreages increase. Fertilization requirements are relatively low, with 50 kg N/ha/year being a good “generic” recommendation where a single harvest is taken after plants have senesced; more will be needed if biomass is harvested while still green. Switchgrass should be harvested no more than twice per year and may generally be expected to produce 12 to ≥20 mg/ha/year across its usual range of distribution. A single harvest may provide for maximum sustainable yields - especially if the harvest is taken after tops die back at the end of the season. Several harvesting technologies are available, but the preferred technology may depend on logistics and economics associated with the local processing point, or biorefinery.

Selecting, establishing, and managing switchgrass (Panicum virgatum) for biofuels.

PubMed

Parrish, David J; Fike, John H

2009-01-01

Switchgrass is being widely considered as a feedstock for biofuel production. Much remains to be learned about ideal feedstock characteristics, but switchgrass offers many advantages already and can perhaps be manipulated to offer more. When planning to grow switchgrass, select a cultivar that is well adapted to the location - generally a lowland cultivar for the southern United States and an upland cultivar at higher latitudes. Plant non-dormant seed after soils are well warmed, preferably with no-till methods and always with good weed control. Except for weeds, few pests appear to be widespread; but disease and insect pests could become more important as acreages increase. Fertilization requirements are relatively low, with 50 kg N/ha/year being a good "generic" recommendation where a single harvest is taken after plants have senesced; more will be needed if biomass is harvested while still green. Switchgrass should be harvested no more than twice per year and may generally be expected to produce 12 to >or=20 mg/ha/year across its usual range of distribution. A single harvest may provide for maximum sustainable yields - especially if the harvest is taken after tops die back at the end of the season. Several harvesting technologies are available, but the preferred technology may depend on logistics and economics associated with the local processing point, or biorefinery.

Isolation, Characterization, and Quantification of Steroidal Saponins in Switchgrass (Panicum virgatum L.)

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) has been identified for development into an efficient and environment friendly biomass energy crop. A recent five-year study demonstrated that switchgrass grown for biofuel production produced 540 percent more energy than what is needed to grow, harvest and process...

Preference by horses for bedding pellets made from switchgrass (Panicum virgatum) straw

USDA-ARS?s Scientific Manuscript database

The bedding system used for stalled horses can impact their health and well-being. This study examined the saponin concentration in switchgrass (Panicum virgatum) straw, and bedding pellets made from switchgrass straw. Further, this study determined the palatability of bedding pellets made from sw...

Depolymerization and hydrodeoxygenation of switchgrass lignin with formic acid.

PubMed

Xu, Weiyin; Miller, Stephen J; Agrawal, Pradeep K; Jones, Christopher W

2012-04-01

Organosolv switchgrass lignin is depolymerized and hydrodeoxygenated with a formic acid hydrogen source, 20 wt % Pt/C catalyst, and ethanol solvent. The combination of formic acid and Pt/C is found to promote production of higher fractions of lower molecular weight compounds in the liquid products. After 4 h of reaction, all of the switchgrass lignin is solubilized and 21 wt % of the biomass is shown to be converted into seven prominent molecular species that are identified and quantified. Reaction time is shown to be an important variable in affecting changes in product distributions and bulk liquid product properties. At 20 h of reaction, the lignin is significantly depolymerized to form liquid products with a 76 % reduction in the weighted average molecular weight. Elemental analysis also shows that the resultant liquid products have a 50 % reduction in O/C and 10 % increase in H/C molar ratios compared to the switchgrass lignin after 20 h. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Grassland bird response to harvesting switchgrass as a biomass energy crop

USGS Publications Warehouse

Roth, A.M.; Sample, D.W.; Ribic, C.A.; Paine, L.; Undersander, D.J.; Bartelt, G.A.

2005-01-01

The combustion of perennial grass biomass to generate electricity may be a promising renewable energy option. Switchgrass (Panicum virgatum) grown as a biofuel has the potential to provide a cash crop for farmers and quality nesting cover for grassland birds. In southwestern Wisconsin (near lat. 42??52???, long. 90??08???), we investigated the impact of an August harvest of switchgrass for bioenergy on community composition and abundance of Wisconsin grassland bird species of management concern. Harvesting the switchgrass in August resulted in changes in vegetation structure and bird species composition the following nesting season. In harvested transects, residual vegetation was shorter and the litter layer was reduced in the year following harvest. Grassland bird species that preferred vegetation of short to moderate height and low to moderate density were found in harvested areas. Unharvested areas provided tall, dense vegetation structure that was especially attractive to tall-grass bird species, such as sedge wren (Cistothorus platensis) and Henslow's sparrow (Ammodramus henslowii). When considering wildlife habitat value in harvest management of switchgrass for biofuel, leaving some fields unharvested each year would be a good compromise, providing some habitat for a larger number of grassland bird species of management concern than if all fields were harvested annually. In areas where most idle grassland habitat present on the landscape is tallgrass, harvest of switchgrass for biofuel has the potential to increase the local diversity of grassland birds.

Economics of intercropping loblolly pine and switchgrass for bioenergy markets in the southeastern United States

Treesearch

Andres Susaeta; Janaki Alavalapati Pankaj Lal; D. Evan Mercer; Douglas Carter

2012-01-01

Abstract The main objective of this study was to assess the economics of alley cropping of loblolly pine (Pinus taeda L.) and switchgrass (Panicum virgatum) in the southern United States. Assuming a price range of switchgrass between $15 and $50 Mg-1 and yield of 12 Mg ha-1 year-1, we investigated the effect of switchgrass production on the optimal forest management...

Early lignin pathway enzymes and routes to chlorogenic acid in switchgrass (Panicum virgatum L.).

PubMed

Escamilla-Treviño, Luis L; Shen, Hui; Hernandez, Timothy; Yin, Yanbin; Xu, Ying; Dixon, Richard A

2014-03-01

Studying lignin biosynthesis in Panicum virgatum (switchgrass) has provided a basis for generating plants with reduced lignin content and increased saccharification efficiency. Chlorogenic acid (CGA, caffeoyl quinate) is the major soluble phenolic compound in switchgrass, and the lignin and CGA biosynthetic pathways potentially share intermediates and enzymes. The enzyme hydroxycinnamoyl-CoA: quinate hydroxycinnamoyltransferase (HQT) is responsible for CGA biosynthesis in tobacco, tomato and globe artichoke, but there are no close orthologs of HQT in switchgrass or in other monocotyledonous plants with complete genome sequences. We examined available transcriptomic databases for genes encoding enzymes potentially involved in CGA biosynthesis in switchgrass. The protein products of two hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyltransferase (HCT) genes (PvHCT1a and PvHCT2a), closely related to lignin pathway HCTs from other species, were characterized biochemically and exhibited the expected HCT activity, preferring shikimic acid as acyl acceptor. We also characterized two switchgrass coumaroyl shikimate 3'-hydroxylase (C3'H) enzymes (PvC3'H1 and PvC3'H2); both of these cytochrome P450s had the capacity to hydroxylate 4-coumaroyl shikimate or 4-coumaroyl quinate to generate caffeoyl shikimate or CGA. Another switchgrass hydroxycinnamoyl transferase, PvHCT-Like1, is phylogenetically distant from HCTs or HQTs, but exhibits HQT activity, preferring quinic acid as acyl acceptor, and could therefore function in CGA biosynthesis. The biochemical features of the recombinant enzymes, the presence of the corresponding activities in plant protein extracts, and the expression patterns of the corresponding genes, suggest preferred routes to CGA in switchgrass.

Dixie Valley Engineered Geothermal System Exploration Methodology Project, Baseline Conceptual Model Report

DOE Data Explorer

Joe Iovenitti

2013-05-15

The Engineered Geothermal System (EGS) Exploration Methodology Project is developing an exploration approach for EGS through the integration of geoscientific data. The Project chose the Dixie Valley Geothermal System in Nevada as a field laboratory site for methodlogy calibration purposes because, in the public domain, it is a highly characterized geothermal systems in the Basin and Range with a considerable amount of geoscience and most importantly, well data. This Baseline Conceptual Model report summarizes the results of the first three project tasks (1) collect and assess the existing public domain geoscience data, (2) design and populate a GIS database, and (3) develop a baseline (existing data) geothermal conceptual model, evaluate geostatistical relationships, and generate baseline, coupled EGS favorability/trust maps from +1km above sea level (asl) to -4km asl for the Calibration Area (Dixie Valley Geothermal Wellfield) to identify EGS drilling targets at a scale of 5km x 5km. It presents (1) an assessment of the readily available public domain data and some proprietary data provided by Terra-Gen Power, LLC, (2) a re-interpretation of these data as required, (3) an exploratory geostatistical data analysis, (4) the baseline geothermal conceptual model, and (5) the EGS favorability/trust mapping. The conceptual model presented applies to both the hydrothermal system and EGS in the Dixie Valley region.

West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

none,

2012-09-27

The West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2011. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2011. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity andmore » accuracy of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2011 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

West Valley Environmental Services LLC

2010-09-17

The West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2009. The report, prepared by the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2009. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program by the DOE ensuremore » the validity and accuracy of the monitoring data. In addition to demonstrating compliance with environmental regulations and directives, evaluation of data collected in 2009 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

West Valley Demonstration Project Annual Site Environmental Report Calendar Year 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

2014-09-16

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2013. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2013. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2013 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrass

USDA-ARS?s Scientific Manuscript database

Background: Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent ...

Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrass

DOE PAGES

Frazier, Taylor P.; Palmer, Nathan A.; Xie, Fuliang; ...

2016-11-08

Switchgrass ( Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass. In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain,more » jacalin-like binding domain, calmodulin-like binding, and thioredoxin. RNA-sequencing analysis of leaf tissue from ‘Alamo’, a rust-resistant switchgrass cultivar, and ‘Dacotah’, a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. RNA-sequencing data from field-grown cultivar ‘Summer’ plants indicated that the expression of some of these RGHs was developmentally regulated. Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop.« less

Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frazier, Taylor P.; Palmer, Nathan A.; Xie, Fuliang

Switchgrass ( Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass. In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain,more » jacalin-like binding domain, calmodulin-like binding, and thioredoxin. RNA-sequencing analysis of leaf tissue from ‘Alamo’, a rust-resistant switchgrass cultivar, and ‘Dacotah’, a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. RNA-sequencing data from field-grown cultivar ‘Summer’ plants indicated that the expression of some of these RGHs was developmentally regulated. Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop.« less

LOWER RIO GRANDE VALLEY TRANSBOUNDARY AIR POLLUTION PROJECT (TAPP) (MAIN REPORT)

EPA Science Inventory

The purpose of the Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was to obtain air quality data for a full year at three border monitoring sites to assess anthropogenic and biogenic emission impacts and transboundary air pollution transport in the Lower Rio...

Plant community and white-tailed deer nutritional carrying capacity response to intercropping switchgrass in loblolly pine plantations

NASA Astrophysics Data System (ADS)

Greene, Ethan Jacob

Switchgrass (Panicum virgatum L.) is a cellulosic feedstock for alternative energy production that could grow well between planted pines (Pinus spp.). Southeastern planted pine occupies 15.8 million hectares and thus, switchgrass intercropping could affect biodiversity if broadly implemented. Therefore, I evaluated effects of intercropping switchgrass in loblolly pine (P. taeda L.) plantations on plant community diversity, plant biomass production, and white-tailed deer (Odocoileus virginianus Zimmerman) nutritional carrying capacity. In a randomized complete block design, I assigned three treatments (switchgrass intercropped, switchgrass monoculture, and a "control" of traditional pine management) to 4 replicates of 10-ha experimental units in Kemper County, Mississippi during 2014-2015. I detected 246 different plant species. Switchgrass intercropping reduced plant species richness and diversity but maintained evenness. I observed reduced forb and high-use deer forage biomass but only in intercropped alleys (interbeds). Soil micronutrient interactions affected forage protein of deer plants. White-tailed deer nutritional carrying capacity remained unaffected.

Visualization of Biomass Solubilization and Cellulose Regeneration during Ionic Liquid Pretreatment of Switchgrass

USDA-ARS?s Scientific Manuscript database

Auto-fluorescent mapping of plant cell walls was used to visualize cellulose and lignin in pristine switchgrass (Panicum virgatum) stems to determine the mechanisms of biomass dissolution during ionic liquid pretreatment. The addition of ground switchgrass to the ionic liquid 1-n-ethyl-3-methylimid...

Modeling differential growth in switchgrass cultivars across the Central and Southern Great Plains

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) has been recognized as a potential biofuel crop, because it is adapted to a wide range of environmental and climatic conditions. Zones of adaptation for many switchgrass cultivars are well documented and attributed to local adaptation to the temperature and photope...

Impact of harvest time and switchgrass cultivar on sugar release through enzymatic hydrolysis

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a native North American prairie grass being developed for bioenergy production in the central and eastern USA. The objective of this study was to identify the impacts harvest time and switchgrass cultivar had on sugar release variables determined through enzymat...

Diversity and population structure of northern switchgrass as revealed though exome capture sequencing

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a polyploid, perennial grass species that is native to North America, and is being developed as a future biofuels feedstock crop. Switchgrass is present primarily in two ecotypes: a northern upland ecotype composed of tetraploid and octoploid accessions, and a so...

Co-processing of agricultural plastic waste and switchgrass via tail gas reactive pyrolysis

USDA-ARS?s Scientific Manuscript database

Mixtures of agricultural plastic waste in the form of polyethylene hay bale covers (PE) (4-37%) and switchgrass were investigated using the US Department of Agriculture’s tail gas reactive pyrolysis (TGRP) at different temperatures (400-570 deg C). TGRP of switchgrass and plastic mixtures significan...

Town of Chino Valley Municipal Water System Improvement Project FONSI and EA

EPA Pesticide Factsheets

EPA Region 9 has prepared an Environmental Assessment (EA) describing the potential environmental impacts associated with, and the alternatives to, the proposed Water System Improvement Project in the town of China Valley, Arizona. This Finding of No Signi

Development of Kinetics and Mathematical Models for High-Pressure Gasification of Lignite-Switchgrass Blends: Cooperative Research and Development Final Report, CRADA Number CRD-11-447

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iisa, Kristiina

2016-04-06

NREL will work with Participant as a subtier partner under DE-FOA-0000240 titled "Co-Production of Power, Fuels, and Chemicals via Coal/Biomass Mixtures." The goal of the project is to determine the gasification characteristics of switchgrass and lignite mixtures and develop kinetic models. NREL will utilize a pressurized thermogravimetric analyzer to measure the reactivity of chars generated in a pressurized entrained-flow reactor at Participant's facilities and to determine the evolution of gaseous species during pyrolysis of switchgrass-lignite mixtures. Mass spectrometry and Fourier-transform infrared analysis will be used to identify and quantify the gaseous species. The results of the project will aid inmore » defining key reactive properties of mixed coal biomass fuels.« less

Integrating future scenario‐based crop expansion and crop conditions to map switchgrass biofuel potential in eastern Nebraska, USA

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.

2018-01-01

Switchgrass (Panicum virgatum) has been evaluated as one potential source for cellulosic biofuel feedstocks. Planting switchgrass in marginal croplands and waterway buffers can reduce soil erosion, improve water quality, and improve regional ecosystem services (i.e. it serves as a potential carbon sink). In previous studies, we mapped high risk marginal croplands and highly erodible cropland buffers that are potentially suitable for switchgrass development, which would improve ecosystem services and minimally impact food production. In this study, we advance our previous study results and integrate future crop expansion information to develop a switchgrass biofuel potential ensemble map for current and future croplands in eastern Nebraska. The switchgrass biomass productivity and carbon benefits (i.e. NEP: net ecosystem production) for the identified biofuel potential ensemble areas were quantified. The future scenario‐based (‘A1B’) land use and land cover map for 2050, the US Geological Survey crop type and Compound Topographic Index (CTI) maps, and long‐term (1981–2010) averaged annual precipitation data were used to identify future crop expansion regions that are suitable for switchgrass development. Results show that 2528 km2 of future crop expansion regions (~3.6% of the study area) are potentially suitable for switchgrass development. The total estimated biofuel potential ensemble area (including cropland buffers, marginal croplands, and future crop expansion regions) is 4232 km2 (~6% of the study area), potentially producing 3.52 million metric tons of switchgrass biomass per year. Converting biofuel ensemble regions to switchgrass leads to potential carbon sinks (the total NEP for biofuel potential areas is 0.45 million metric tons C) and is environmentally sustainable. Results from this study improve our understanding of environmental conditions and ecosystem services of current and future cropland systems in eastern Nebraska and provide

Reduction of ethanol yield from switchgrass infected with rust caused by Puccinia emaculata

DOE PAGES

Sykes, Virginia R.; Allen, Fred L.; Mielenz, Jonathan R.; ...

2015-10-16

Switchgrass ( Panicum virgatum) is an important biofuel crop candidate thought to have low disease susceptibility. As switchgrass production becomes more prevalent, monoculture and production fields in close proximity to one another may increase the spread and severity of diseases such as switchgrass rust caused by the pathogen Puccinia emaculata. The objective of this research was to examine the impact of rust on ethanol yield in switchgrass. In 2010 and 2012, naturally infected leaves from field-grown Alamo and Kanlow in Knoxville, TN (2010, 2012) and Crossville, TN (2012) were visually categorized as exhibiting low, medium, or high disease based onmore » the degree of chlorosis and sporulation. P. emaculata was isolated from each disease range to confirm infection. Samples from 2010 were acid/heat pretreated and subjected to two runs of simultaneous saccharification and fermentation (SSF) with Saccharomyces cerevisiae D 5A to measure ethanol yield. Near-infrared spectroscopy (NIRS) was used to estimate ethanol yield for 2012 samples. SSF and NIRS data were analyzed separately using ANOVA. Disease level effects were significant within both models (P < 0.05) and both models explained a large amount of variation in ETOH (SSF: R 2 = 0.99, NIRS: R 2 = 0.99). In the SSF dataset, ethanol was reduced by 35 % in samples exhibiting medium disease symptoms and by 55 % in samples exhibiting high disease symptoms. In the NIRS dataset, estimated ethanol was reduced by 10 % in samples exhibiting medium disease symptoms and by 21 % in samples exhibiting high disease symptoms. Lastly, results indicate that switchgrass rust will likely have a negative impact on ethanol yield in switchgrass grown as a biofuel crop.« less

Reduction of ethanol yield from switchgrass infected with rust caused by Puccinia emaculata

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sykes, Virginia R.; Allen, Fred L.; Mielenz, Jonathan R.

Switchgrass ( Panicum virgatum) is an important biofuel crop candidate thought to have low disease susceptibility. As switchgrass production becomes more prevalent, monoculture and production fields in close proximity to one another may increase the spread and severity of diseases such as switchgrass rust caused by the pathogen Puccinia emaculata. The objective of this research was to examine the impact of rust on ethanol yield in switchgrass. In 2010 and 2012, naturally infected leaves from field-grown Alamo and Kanlow in Knoxville, TN (2010, 2012) and Crossville, TN (2012) were visually categorized as exhibiting low, medium, or high disease based onmore » the degree of chlorosis and sporulation. P. emaculata was isolated from each disease range to confirm infection. Samples from 2010 were acid/heat pretreated and subjected to two runs of simultaneous saccharification and fermentation (SSF) with Saccharomyces cerevisiae D 5A to measure ethanol yield. Near-infrared spectroscopy (NIRS) was used to estimate ethanol yield for 2012 samples. SSF and NIRS data were analyzed separately using ANOVA. Disease level effects were significant within both models (P < 0.05) and both models explained a large amount of variation in ETOH (SSF: R 2 = 0.99, NIRS: R 2 = 0.99). In the SSF dataset, ethanol was reduced by 35 % in samples exhibiting medium disease symptoms and by 55 % in samples exhibiting high disease symptoms. In the NIRS dataset, estimated ethanol was reduced by 10 % in samples exhibiting medium disease symptoms and by 21 % in samples exhibiting high disease symptoms. Lastly, results indicate that switchgrass rust will likely have a negative impact on ethanol yield in switchgrass grown as a biofuel crop.« less

Seasonal below-ground metabolism in switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum) a perennial, polyploid, C4 warm-season grass is one of the foremost herbaceous species being advanced as a source of biomass for biofuel end uses. At the end of every growing season, the aerial tissues senesce, and the below-ground rhizomes become dormant. Future growt...

Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

NASA Astrophysics Data System (ADS)

Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

2010-10-01

This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

Allelopathic potential of switchgrass (Panicum virgatum L.) on perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.).

PubMed

Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

2010-10-01

This study investigated allelopathy and its chemical basis in nine switchgrass (Panicum virgatum L.) accessions. Perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China's Loess Plateau.

Fox Valley Technical College New Occupational Markets: Market Research Project Results.

ERIC Educational Resources Information Center

Mishler, Carol

This is a report on the results of a market research project conducted by Fox Valley Technical College (FVTC) (Wisconsin) to identify new occupational markets in the college's service area. The college scanned national job lists, employment databases, and northeastern Wisconsin employer advertisements. The college also surveyed employers in the…

A visual progression of the Fort Valley Restoration Project treatments using remotely sensed imagery (P-53)

Treesearch

Joseph E. Crouse; Peter Z. Fule

2008-01-01

The landscape surrounding the Fort Valley Experimental Forest in northern Arizona has changed dramatically in the past decade due to the Fort Valley Restoration Project, a collaboration between the Greater Flagstaff Forest Partnership, Coconino National Forest, and Rocky Mountain Research Station. Severe wildfires in 1996 sparked community concern to start restoration...

Mild pyrolysis of P3HB/Switchgrass blends for the production of bio-oil enriched with crotonic acid

USDA-ARS?s Scientific Manuscript database

The mild pyrolysis of switchgrass/poly-3-hydroxybutyrate (P3HB) blends that mimic P3HB-producing switchgrass lines was studied in a pilot scale fluidized bed reactor with the goal of simultaneously producing crotonic acid and switchgrass-based bio-oil. Factors such as pyrolysis temperature, residenc...

West Valley Demonstration Project Annual Site Environmental Report (ASER) Calendar Year (2016)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, Alison F.; Pendl, Michael P.; Steiner, II, Robert E.

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2016. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2016. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2016 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

Synergistic and Antagonistic Effects of Salinity and pH on Germination in Switchgrass (Panicum virgatum L.)

PubMed Central

Liu, Yuan; Wang, Quanzhen; Zhang, Yunwei; Cui, Jian; Chen, Guo; Xie, Bao; Wu, Chunhui; Liu, Haitao

2014-01-01

The effects of salt-alkaline mixed stress on switchgrass were investigated by evaluating seed germination and the proline, malondialdehyde (MDA) and soluble sugar contents in three switchgrass (Panicum virgatum L.) cultivars in order to identify which can be successfully produced on marginal lands affected by salt-alkaline mixed stress. The experimental conditions consisted of four levels of salinity (10, 60, 110 and 160 mM) and four pH levels (7.1, 8.3, 9.5 and 10.7). The effects of salt-alkaline mixed stress with equivalent coupling of the salinity and pH level on the switchgrass were explored via model analyses. Switchgrass was capable of germinating and surviving well in all treatments under low-alkaline pH (pH≤8.3), regardless of the salinity. However, seed germination and seedling growth were sharply reduced at higher pH values in conjunction with salinity. The salinity and pH had synergetic effects on the germination percentage, germination index, plumular length and the soluble sugar and proline contents in switchgrass. However, these two factors exhibited antagonistic effects on the radicular length of switchgrass. The combined effects of salinity and pH and the interactions between them should be considered when evaluating the strength of salt-alkaline mixed stress. PMID:24454834

Genome-size variation in switchgrass (Panicum virgatum): flow cytometry and cytology reveal rampant aneuploidy

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.), a native perennial dominant of the prairies of North America, has been targeted as a model herbaceous species for biofeedstock development. A flow-cytometric survey of a core set of 11 primarily upland polyploid switchgrass accessions indicated that there was con...

New genomic resources for switchgrass: a BAC library and comparative analysis of homoeologous genomic regions harboring bioenergy traits

PubMed Central

2011-01-01

Background Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18) to duodecaploid (12X = 108). Like in other large, repeat-rich plant genomes, this genomic complexity will hinder whole genome sequencing efforts. An extensive physical map providing enough information to resolve the homoeologous genomes would provide the necessary framework for accurate assembly of the switchgrass genome. Results A switchgrass BAC library constructed by partial digestion of nuclear DNA with EcoRI contains 147,456 clones covering the effective genome approximately 10 times based on a genome size of 3.2 Gigabases (~1.6 Gb effective). Restriction digestion and PFGE analysis of 234 randomly chosen BACs indicated that 95% of the clones contained inserts, ranging from 60 to 180 kb with an average of 120 kb. Comparative sequence analysis of two homoeologous genomic regions harboring orthologs of the rice OsBRI1 locus, a low-copy gene encoding a putative protein kinase and associated with biomass, revealed that orthologous clones from homoeologous chromosomes can be unambiguously distinguished from each other and correctly assembled to respective fingerprint contigs. Thus, the data obtained not only provide genomic resources for further analysis of switchgrass genome, but also improve efforts for an accurate genome sequencing strategy. Conclusions The construction of the first switchgrass BAC library and comparative analysis of homoeologous harboring OsBRI1

New genomic resources for switchgrass: a BAC library and comparative analysis of homoeologous genomic regions harboring bioenergy traits.

PubMed

Saski, Christopher A; Li, Zhigang; Feltus, Frank A; Luo, Hong

2011-07-18

Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18) to duodecaploid (12X = 108). Like in other large, repeat-rich plant genomes, this genomic complexity will hinder whole genome sequencing efforts. An extensive physical map providing enough information to resolve the homoeologous genomes would provide the necessary framework for accurate assembly of the switchgrass genome. A switchgrass BAC library constructed by partial digestion of nuclear DNA with EcoRI contains 147,456 clones covering the effective genome approximately 10 times based on a genome size of 3.2 Gigabases (~1.6 Gb effective). Restriction digestion and PFGE analysis of 234 randomly chosen BACs indicated that 95% of the clones contained inserts, ranging from 60 to 180 kb with an average of 120 kb. Comparative sequence analysis of two homoeologous genomic regions harboring orthologs of the rice OsBRI1 locus, a low-copy gene encoding a putative protein kinase and associated with biomass, revealed that orthologous clones from homoeologous chromosomes can be unambiguously distinguished from each other and correctly assembled to respective fingerprint contigs. Thus, the data obtained not only provide genomic resources for further analysis of switchgrass genome, but also improve efforts for an accurate genome sequencing strategy. The construction of the first switchgrass BAC library and comparative analysis of homoeologous harboring OsBRI1 orthologs present a glimpse into

WEST VALLEY DEMONSTRATION PROJECT ANNUAL SITE ENVIRONMENTAL REPORT CALENDAR YEAR 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2003-09-12

This annual environmental monitoring report for the West Valley Demonstration Project (WVDP or Project) is published to inform those with interest about environmental conditions at the WVDP. In accordance with U.S. Department of Energy (DOE) Order 231.1, Environment, Safety, and Health Reporting, the report summarizes calendar year (CY) 2002 environmental monitoring data so as to describe the performance of the WVDP's environmental management system, confirm compliance with standards and regulations, and highlight important programs. In 2002, the West Valley Demonstration Project, the site of a DOE environmental cleanup activity operated by West Valley Nuclear Services Co. (WVNSCO), was in themore » final stages of stabilizing high-level radioactive waste (HLW) that remained at the site after commercial nuclear fuel reprocessing had been discontinued in the early 1970s. The Project is located in western New York State, about 30 miles south of Buffalo, within the New York State-owned Western New York Nuclear Service Center (WNYNSC). The WVDP is being conducted in cooperation with the New York State Energy Research and Development Authority (NYSERDA). Ongoing work activities at the WVDP during 2002 included: (1) completing HLW solidification and melter shutdown; (2) shipping low-level radioactive waste off-site for disposal; (3) constructing a facility where large high-activity components can be safely packaged for disposal; (4) packaging and removing spent materials from the vitrification facility; (5) preparing environmental impact statements for future activities; (6) removing as much of the waste left behind in waste tanks 8D-1 and 8D-2 as was reasonably possible; (7) removing storage racks, canisters, and debris from the fuel receiving and storage pool, decontaminating pool walls, and beginning shipment of debris for disposal; (8) ongoing decontamination in the general purpose cell and the process mechanical cell (also referred to as the head end cells); (9

Topsoil thickness influences nitrogen management of switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is an attractive bioenergy crop option for eroded portions of claypan landscapes where grain crop production is marginally profitable. Topsoil thickness above the claypan or depth to claypan (DTC) can vary widely within fields and little information exists on its im...

Model evaluation of plant metal content and biomass yield for the phytoextraction of heavy metals by switchgrass.

PubMed

Chen, Bo-Ching; Lai, Hung-Yu; Juang, Kai-Wei

2012-06-01

To better understand the ability of switchgrass (Panicum virgatum L.), a perennial grass often relegated to marginal agricultural areas with minimal inputs, to remove cadmium, chromium, and zinc by phytoextraction from contaminated sites, the relationship between plant metal content and biomass yield is expressed in different models to predict the amount of metals switchgrass can extract. These models are reliable in assessing the use of switchgrass for phytoremediation of heavy-metal-contaminated sites. In the present study, linear and exponential decay models are more suitable for presenting the relationship between plant cadmium and dry weight. The maximum extractions of cadmium using switchgrass, as predicted by the linear and exponential decay models, approached 40 and 34 μg pot(-1), respectively. The log normal model was superior in predicting the relationship between plant chromium and dry weight. The predicted maximum extraction of chromium by switchgrass was about 56 μg pot(-1). In addition, the exponential decay and log normal models were better than the linear model in predicting the relationship between plant zinc and dry weight. The maximum extractions of zinc by switchgrass, as predicted by the exponential decay and log normal models, were about 358 and 254 μg pot(-1), respectively. To meet the maximum removal of Cd, Cr, and Zn, one can adopt the optimal timing of harvest as plant Cd, Cr, and Zn approach 450 and 526 mg kg(-1), 266 mg kg(-1), and 3022 and 5000 mg kg(-1), respectively. Due to the well-known agronomic characteristics of cultivation and the high biomass production of switchgrass, it is practicable to use switchgrass for the phytoextraction of heavy metals in situ. Copyright © 2012 Elsevier Inc. All rights reserved.

Watershed-scale Hydrology and Water Quality Impact of Switchgrass Intercropping in Southern Managed Pine Forests

NASA Astrophysics Data System (ADS)

Chescheir, G. M.; Birgand, F.; Allen, E.; Bennett, E.; Carter, T.; Dobbs, N.; Muwamba, A.; Amatya, D. M.; Youssef, M.; Nettles, J. E.

2016-12-01

The use of marginal land for cellulosic biofuel crop production is an attractive solution to preserve agricultural land for food production. The space available between rows of young loblolly pine (Pinus taeda) trees offers enough light to support growth of biofuel crops for several years. A five year field study was conducted to assess the hydrology and water quality impacts of switchgrass (Panicum virgatum) intercropping with pine trees in watersheds of the southeastern US. Paired-watershed studies were replicated in Mississippi and Alabama on upland sites, and in North Carolina on a flat lowland site. In each state, the impact of switchgrass intercropping was assessed from differences in water and nutrient yields from contiguous 20-40 ha watersheds established as: conventional young pine plantation, switchgrass intercropped in young pine plantation, switchgrass only, and mid-rotation mature pine plantation. A total of 14 watersheds were equipped with continuous flow monitoring stations, flow proportional water samplers, groundwater wells, soil moisture sensors and weather stations. Data collection continued through a two year pre-treatment period, a one year treatment period when field operations were conducted to establish switchgrass, and a two year post-treatment period when the established switchgrass was fertilized and harvested annually. Our results showed that significant increases in total suspended solids (TSS) and nitrogen (N) loading occurred during the treatment periods at the upland sites in MS and AL. During the post treatment periods, TSS and N loading decreased to levels near those observed in pretreatment. At the lowland site, only nitrogen loading was increased during the treatment period. Concentrations of TSS at the lowland site were two orders of magnitude lower than those observed at the upland sites and were not significantly affected by the treatment. Inherent flow variability between watersheds within sites made detection of subtle

Isolation and characterization of unhydrolyzed oligosaccharides from switchgrass (Panicum virgatum, L.) xylan after exhaustive enzymatic treatment with commercial enzyme preparations

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum, L.) is a potential renewable source of carbohydrates for use in microbial conversion to biofuels. Xylan comprises approximately 30% of the switchgrass cell wall. To understand the limitations of commercial enzyme mixtures, alkali-extracted, isolated switchgrass xylan w...

Accuracy of genomic prediction in switchgrass (Panicum virgatum L.) improved by accounting for linkage disequilibrium

USDA-ARS?s Scientific Manuscript database

Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection is an attractive technology to generate rapid genetic gains in switchgrass and ...

Determining switchgrass biomass supplies for cellulosic biorefineries

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is being developed into a bioenergy crop for use in temperate regions of the USA. Information on spatial and temporial variation for stands and biomass yield among and within fields in large agroecoregions is not available. A reliable feedstock supply will be essent...

Targeted discovery of glycoside hydrolases from a switchgrass-adapted compost community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allgaier, M.; Reddy, A.; Park, J. I.

2009-11-15

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Small-subunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence datamore » from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, {approx}10% were putative cellulases mostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50 C and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.« less

Targeted Discovery of Glycoside Hydrolases from a Switchgrass-Adapted Compost Community

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, Amitha; Allgaier, Martin; Park, Joshua I.

2011-05-11

Development of cellulosic biofuels from non-food crops is currently an area of intense research interest. Tailoring depolymerizing enzymes to particular feedstocks and pretreatment conditions is one promising avenue of research in this area. Here we added a green-waste compost inoculum to switchgrass (Panicum virgatum) and simulated thermophilic composting in a bioreactor to select for a switchgrass-adapted community and to facilitate targeted discovery of glycoside hydrolases. Smallsubunit (SSU) rRNA-based community profiles revealed that the microbial community changed dramatically between the initial and switchgrass-adapted compost (SAC) with some bacterial populations being enriched over 20-fold. We obtained 225 Mbp of 454-titanium pyrosequence datamore » from the SAC community and conservatively identified 800 genes encoding glycoside hydrolase domains that were biased toward depolymerizing grass cell wall components. Of these, ,10percent were putative cellulasesmostly belonging to families GH5 and GH9. We synthesized two SAC GH9 genes with codon optimization for heterologous expression in Escherichia coli and observed activity for one on carboxymethyl cellulose. The active GH9 enzyme has a temperature optimum of 50uC and pH range of 5.5 to 8 consistent with the composting conditions applied. We demonstrate that microbial communities adapt to switchgrass decomposition using simulated composting condition and that full-length genes can be identified from complex metagenomic sequence data, synthesized and expressed resulting in active enzyme.« less

Modeling analysis on germination and seedling growth using ultrasound seed pretreatment in switchgrass.

PubMed

Wang, Quanzhen; Chen, Guo; Yersaiyiti, Hayixia; Liu, Yuan; Cui, Jian; Wu, Chunhui; Zhang, Yunwei; He, Xueqing

2012-01-01

Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds.

Breeding bird community response to establishing intercropped switchgrass in intensively-managed pine stands

USGS Publications Warehouse

Loman, Zachary G.; Riffell, Samuel K.; Wheat, Bradley R.; Miller, Darrin A.; Martin, James A.; Vilella, Francisco

2014-01-01

Intercropping switchgrass (Panicum virgatum L.) between tree rows within young pine (Pinus spp.) plantations is a potential method to generate lignocellulosic biofuel feedstocks within intensively managed forests. Intensively managed pine supports a diverse avian assemblage potentially affected by establishment and maintenance of an annual biomass feedstock via changes in plant communities, dead wood resources, and habitat structure. We sought to understand how establishing switchgrass on an operational scale affects bird communities within intercropped plantations as compared to typical intensively managed loblolly pine (Pinus taeda L.) forest. We conducted breeding bird point counts using distance sampling for three years (2011–2013) following establishment of intercropped switchgrass stands (6 replicates), traditionally-managed pine plantations, and switchgrass-only plots (0.1 km2 minimum) in Kemper Co., MS. We detected 59 breeding bird species from 11,195 detections. Neotropical migrants and forest-edge associated species were less abundant in intercropped plots than controls the first two years after establishment and more abundant in year three. Short distance migrants and residents were scarce in intercropped and control plots initially, and did not differ between these two treatments in any year. Species associated with pine-grass habitat structure were less abundant initially in intercropped plots, but converged with pine controls in subsequent years. Switchgrass monocultures provided minimal resources for birds. If songbird conservation is a management priority, managers should consider potential reductions of some breeding birds for one to two years following intercropping. It is unclear how these relationships may change outside the breeding season and as stands age.

Transcriptional and physiological data reveal the dehydration memory behavior in switchgrass (Panicum virgatum L.).

PubMed

Zhang, Chao; Peng, Xi; Guo, Xiaofeng; Tang, Gaijuan; Sun, Fengli; Liu, Shudong; Xi, Yajun

2018-01-01

Switchgrass ( Panicum virgatum L.) is a model biofuel plant because of its high biomass, cellulose-richness, easy degradation to ethanol, and the availability of extensive genomic information. However, a little is currently known about the molecular responses of switchgrass plants to dehydration stress, especially multiple dehydration stresses. Studies on the transcriptional profiles of 35-day-old tissue culture plants revealed 741 dehydration memory genes. Gene Ontology and pathway analysis showed that these genes were enriched in phenylpropanoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Further analysis of specific pathways combined with physiological data suggested that switchgrass improved its dehydration resistance by changing various aspects of its responses to secondary dehydration stress (D2), including the regulation of abscisic acid (ABA) and jasmonic acid (JA) biosynthesis and signal transduction, the biosynthesis of osmolytes (l-proline, stachyose and trehalose), energy metabolism (i.e., metabolic process relating to photosynthetic systems, glycolysis, and the TCA cycle), and lignin biosynthesis. The transcriptional data and chemical substance assays showed that ABA was significantly accumulated during both primary (D1) and secondary (D2) dehydration stresses, whereas JA accumulated during D1 but became significantly less abundant during D2. This suggests the existence of a complicated signaling network of plant hormones in response to repeated dehydration stresses. A homology analysis focusing on switchgrass, maize, and Arabidopsis revealed the conservation and species-specific distribution of dehydration memory genes. The molecular responses of switchgrass plants to successive dehydration stresses have been systematically characterized, revealing a previously unknown transcriptional memory behavior. These results provide new insights into the mechanisms of dehydration stress responses in plants. The genes and

The Ohio River Valley CO2 Storage Project AEP Mountaineer Plan, West Virginia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeraj Gupta

2009-01-07

This report includes an evaluation of deep rock formations with the objective of providing practical maps, data, and some of the issues considered for carbon dioxide (CO{sub 2}) storage projects in the Ohio River Valley. Injection and storage of CO{sub 2} into deep rock formations represents a feasible option for reducing greenhouse gas emissions from coal-burning power plants concentrated along the Ohio River Valley area. This study is sponsored by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL), American Electric Power (AEP), BP, Ohio Coal Development Office, Schlumberger, and Battelle along with its Pacific Northwest Division. Anmore » extensive program of drilling, sampling, and testing of a deep well combined with a seismic survey was used to characterize the local and regional geologic features at AEP's 1300-megawatt (MW) Mountaineer Power Plant. Site characterization information has been used as part of a systematic design feasibility assessment for a first-of-a-kind integrated capture and storage facility at an existing coal-fired power plant in the Ohio River Valley region--an area with a large concentration of power plants and other emission sources. Subsurface characterization data have been used for reservoir simulations and to support the review of the issues relating to injection, monitoring, strategy, risk assessment, and regulatory permitting. The high-sulfur coal samples from the region have been tested in a capture test facility to evaluate and optimize basic design for a small-scale capture system and eventually to prepare a detailed design for a capture, local transport, and injection facility. The Ohio River Valley CO{sub 2} Storage Project was conducted in phases with the ultimate objectives of demonstrating both the technical aspects of CO{sub 2} storage and the testing, logistical, regulatory, and outreach issues related to conducting such a project at a large point source under realistic constraints. The

Growth promotion and colonization of switchgrass (Panicum virgatum) cv. Alamo by bacterial endophyte Burkholderia phytofirmans strain PsJN

PubMed Central

2012-01-01

Background Switchgrass is one of the most promising bioenergy crop candidates for the US. It gives relatively high biomass yield and can grow on marginal lands. However, its yields vary from year to year and from location to location. Thus it is imperative to develop a low input and sustainable switchgrass feedstock production system. One of the most feasible ways to increase biomass yields is to harness benefits of microbial endophytes. Results We demonstrate that one of the most studied plant growth promoting bacterial endophytes, Burkholderia phytofirmans strain PsJN, is able to colonize and significantly promote growth of switchgrass cv. Alamo under in vitro, growth chamber, and greenhouse conditions. In several in vitro experiments, the average fresh weight of PsJN-inoculated plants was approximately 50% higher than non-inoculated plants. When one-month-old seedlings were grown in a growth chamber for 30 days, the PsJN-inoculated Alamo plants had significantly higher shoot and root biomass compared to controls. Biomass yield (dry weight) averaged from five experiments was 54.1% higher in the inoculated treatment compared to non-inoculated control. Similar results were obtained in greenhouse experiments with transplants grown in 4-gallon pots for two months. The inoculated plants exhibited more early tillers and persistent growth vigor with 48.6% higher biomass than controls. We also found that PsJN could significantly promote growth of switchgrass cv. Alamo under sub-optimal conditions. However, PsJN-mediated growth promotion in switchgrass is genotype specific. Conclusions Our results show B. phytofirmans strain PsJN significantly promotes growth of switchgrass cv. Alamo under different conditions, especially in the early growth stages leading to enhanced production of tillers. This phenomenon may benefit switchgrass establishment in the first year. Moreover, PsJN significantly stimulated growth of switchgrass cv. Alamo under sub-optimal conditions

West Valley Demonstration Project Annual Site Environmental Report (ASER) for Calendar Year 2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2014. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2014. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2014 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

West Valley Demonstration Project Annual Site Environmental Report (ASER) for Calendar Year 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rendall, John D.; Steiner, Alison F.; Pendl, Michael P.

West Valley Demonstration Project (WVDP) Annual Site Environmental Report (ASER) for Calendar Year 2015. The report, prepared for the U.S. Department of Energy West Valley Demonstration Project office (DOE-WVDP), summarizes the environmental protection program at the WVDP for calendar year (CY) 2015. Monitoring and surveillance of the facilities used by the DOE are conducted to verify protection of public health and safety and the environment. The report is a key component of DOE’s effort to keep the public informed of environmental conditions at the WVDP. The quality assurance protocols applied to the environmental monitoring program ensure the validity and accuracymore » of the monitoring data. In addition to demonstrating compliance with environmental laws, regulations, and directives, evaluation of data collected in 2015 continued to indicate that WVDP activities pose no threat to public health or safety, or to the environment.« less

Extended light exposure increases stem digestibility and biomass production of switchgrass

PubMed Central

Zhao, Chunqiao; Hou, Xincun; Zhu, Yi; Yue, Yuesen; Wu, Juying

2017-01-01

Switchgrass is a photoperiod-sensitive energy grass suitable for growing in the marginal lands of China. We explored the effects of extended photoperiods of low-irradiance light (7 μmol·m-2·s-1, no effective photosynthesis) on the growth, the biomass dry weight, the biomass allocation, and, especially, the stem digestibility and cell wall characteristics of switchgrass. Two extended photoperiods (i.e., 18 and 24 h) were applied over Alamo. Extended light exposure (18 and 24 h) resulted in delayed heading and higher dry weights of vegetative organs (by 32.87 and 35.94%, respectively) at the expense of reducing the amount of sexual organs (by 40.05 and 50.87%, respectively). Compared to the control group (i.e., natural photoperiod), the yield of hexoses (% dry matter) in the stems after a direct enzymatic hydrolysis (DEH) treatment significantly increased (by 44.02 and 46.10%) for those groups irradiated during 18 and 24 h, respectively. Moreover, the yield of hexoses obtained via enzymatic hydrolysis increased after both basic (1% NaOH) and acid (1% H2SO4) pretreatments for the groups irradiated during 18 and 24 h. Additionally, low-irradiance light extension (LILE) significantly increased the content of non-structural carbohydrates (NSCs) while notably reducing the lignin content and the syringyl to guaiacyl (S/G) ratio. These structural changes were in part responsible for the observed improved stem digestibility. Remarkably, LILE significantly decreased the cellulose crystallinity index (CrI) of switchgrass by significantly increasing both the arabinose substitution degree in xylan and the content of ammonium oxalate-extractable uronic acids, both favoring cellulose digestibility. Despite this LILE technology is not applied to the cultivation of switchgrass on a large scale yet, we believe that the present work is important in that it reveals important relationships between extended day length irradiations and biomass production and quality. Additionally, this

Extended light exposure increases stem digestibility and biomass production of switchgrass.

PubMed

Zhao, Chunqiao; Fan, Xifeng; Hou, Xincun; Zhu, Yi; Yue, Yuesen; Wu, Juying

2017-01-01

Switchgrass is a photoperiod-sensitive energy grass suitable for growing in the marginal lands of China. We explored the effects of extended photoperiods of low-irradiance light (7 μmol·m-2·s-1, no effective photosynthesis) on the growth, the biomass dry weight, the biomass allocation, and, especially, the stem digestibility and cell wall characteristics of switchgrass. Two extended photoperiods (i.e., 18 and 24 h) were applied over Alamo. Extended light exposure (18 and 24 h) resulted in delayed heading and higher dry weights of vegetative organs (by 32.87 and 35.94%, respectively) at the expense of reducing the amount of sexual organs (by 40.05 and 50.87%, respectively). Compared to the control group (i.e., natural photoperiod), the yield of hexoses (% dry matter) in the stems after a direct enzymatic hydrolysis (DEH) treatment significantly increased (by 44.02 and 46.10%) for those groups irradiated during 18 and 24 h, respectively. Moreover, the yield of hexoses obtained via enzymatic hydrolysis increased after both basic (1% NaOH) and acid (1% H2SO4) pretreatments for the groups irradiated during 18 and 24 h. Additionally, low-irradiance light extension (LILE) significantly increased the content of non-structural carbohydrates (NSCs) while notably reducing the lignin content and the syringyl to guaiacyl (S/G) ratio. These structural changes were in part responsible for the observed improved stem digestibility. Remarkably, LILE significantly decreased the cellulose crystallinity index (CrI) of switchgrass by significantly increasing both the arabinose substitution degree in xylan and the content of ammonium oxalate-extractable uronic acids, both favoring cellulose digestibility. Despite this LILE technology is not applied to the cultivation of switchgrass on a large scale yet, we believe that the present work is important in that it reveals important relationships between extended day length irradiations and biomass production and quality. Additionally, this

Early competitive effects on growth of loblolly pine grown in co-culture with switchgrass

Treesearch

Kurt J. Krapfl; Scott D. Roberts; Randall J. Rosseau; Jeff A. Hatten

2015-01-01

This study: (1) examined competitive interactions between switchgrass and loblolly pine grown in co-culture, and (2) assessed early growth rates of loblolly pine as affected by differing switchgrass competition treatments. Co-cultures were established and monitored on two Upper Coastal Plain sites for 2 years. The Pontotoc site has a history of agricultural use with...

Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

DOE PAGES

Ibrahim, Mostafa; Hong, Chang Oh.; Singh, Shikha; ...

2017-01-25

The purpose of this study was to assess the changes in switchgrass (Panicum virgatum L.) biomass quality as affected by N rate, harvest time, and storage. This research was conducted near Bristol, SD, in 2010 and 2011. Treatments included three N rates (0, 56, and 112 kg N ha –1) applied annually and each N rate replicated four times. After a killing frost, all of the plots were harvested and baled in large round bales in October 2010 and November 2011. An area of about 30 m 2 from each plot was left unharvested to represent storage of standing switchgrassmore » over the winter and to determine dry matter yields. Switchgrass was analyzed for hemicellulose, cellulose, lignin, mineral elements, N, and C. In the first season, storage of the fall harvested switchgrass bales numerically increased the concentrations of hemicellulose, lignin, and N. In the second season, they increased significantly. Mineral elements significantly increased in both sampling seasons. Delaying harvest until spring decreased lignin, N, and mineral elements concentration, and increased cellulose and hemicellulose concentrations, but also reduced biomass yield. Results from this study suggest that delaying the switchgrass harvest until spring increased the overall feedstock quality for ethanol production, but yield reductions must be considered to determine the overall economic impact of a delayed harvest.« less

Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibrahim, Mostafa; Hong, Chang Oh.; Singh, Shikha

The purpose of this study was to assess the changes in switchgrass (Panicum virgatum L.) biomass quality as affected by N rate, harvest time, and storage. This research was conducted near Bristol, SD, in 2010 and 2011. Treatments included three N rates (0, 56, and 112 kg N ha –1) applied annually and each N rate replicated four times. After a killing frost, all of the plots were harvested and baled in large round bales in October 2010 and November 2011. An area of about 30 m 2 from each plot was left unharvested to represent storage of standing switchgrassmore » over the winter and to determine dry matter yields. Switchgrass was analyzed for hemicellulose, cellulose, lignin, mineral elements, N, and C. In the first season, storage of the fall harvested switchgrass bales numerically increased the concentrations of hemicellulose, lignin, and N. In the second season, they increased significantly. Mineral elements significantly increased in both sampling seasons. Delaying harvest until spring decreased lignin, N, and mineral elements concentration, and increased cellulose and hemicellulose concentrations, but also reduced biomass yield. Results from this study suggest that delaying the switchgrass harvest until spring increased the overall feedstock quality for ethanol production, but yield reductions must be considered to determine the overall economic impact of a delayed harvest.« less

Response of Alamo switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee, USA

USDA-ARS?s Scientific Manuscript database

The purpose of this research was to examine above- and belowground responses to nitrogen fertilization in 5-year old “Alamo” switchgrass (Panicum virgatum). A fertilizer experiment included spring and fall sampling of switchgrass grown under annual applications of 0, 67, and 202 kg N ha-1. Nitrogen ...

Switchgrass biochar affects two aridisols.

PubMed

Ippolito, J A; Novak, J M; Busscher, W J; Ahmedna, M; Rehrah, D; Watts, D W

2012-01-01

The use of biochar has received growing attention because of its ability to improve the physicochemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on its effects in Aridisols. We investigated the effect of low or high temperature (250 or 500°C) pyrolyzed switchgrass () biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to a Declo loam (Xeric Haplocalcids) or to a Warden very fine sandy loam (Xeric Haplocambids) and incubated at 15% moisture content (by weight) for 127 d; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized HO on Days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO-N, NO-N, and NH-N concentrations were quantified. On termination of the incubation, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO-N, and NH-N, total C, inorganic C, organic C, and pH. Compared with 250°C, the 500°C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250°C switchgrass biochar, likely due to binding by biochar's functional group sites. Both biochars caused an increase in leachate K, whereas the 500°C biochar increased leachate P. Both biochars reduced leachate NO-N concentrations compared with the control; however, the 250°C biochar reduced NO-N concentrations to the greatest extent. Easily degradable C, associated with the 250°C biochar's structural make-up, likely stimulated microbial growth, which caused NO-N immobilization. Soil-extractable K, P, and NO-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250°C could improve environmental quality in calcareous soil

Sodium Hydroxide Pretreatment of Switchgrass for Ethanol Production

USDA-ARS?s Scientific Manuscript database

Lignocellulose-to-ethanol conversion is a promising technology to supplement corn-based ethanol production. However, the recalcitrant structure of lignocellulosic material is a major obstacle to the efficient conversion. To improve the enzymatic digestibility of switchgrass for the fermentable sugar...

Biomass production by fescue and switchgrass alone and in mixed swards with legumes. Final project report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, M.

In assessing the role of biomass in alleviating potential global warming, the absence of information on the sustainability of biomass production on soils of limited agricultural potential is cited as a major constraint to the assessment of the role of biomass. Research on the sustainability of yields, recycling of nutrients, and emphasis on reduced inputs of agricultural chemicals in the production of biomass are among the critical research needs to clarify optimum cropping practice in biomass production. Two field experiments were conducted between 1989 and 1993. One study evaluated biomass production and composition of switchgrass (Panicum virgatum L.) grown alonemore » and with bigflower vetch (Vicia grandiflora L.) and the other assessed biomass productivity and composition of tall fescue (Festuca arundinacea Schreb.) grown alone and with perennial legumes. Switchgrass received 0, 75 or 150 kg ha{sup {minus}1} of N annually as NH{sub 4}NO{sub 3} or was interseeded with vetch. Tall fescue received 0, 75, 150 or 225 kg ha{sup {minus}1} of N annually or was interseeded with alfalfa (Medicago L.) or birdsfoot trefoil (Lotus corniculatus L.). It is hoped that production systems can be designed to produce high yields of biomass with minimal inputs of fertilizer N. Achievement of this goal would reduce the potential for movement of NO{sub 3} and other undesirable N forms outside the biomass production system into the environment. In addition, management systems involving legumes could reduce the cost of biomass production.« less

77 FR 31037 - Notice of Segregation of Public Lands for the Proposed Hyder Valley Solar Energy Project in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-24

...; AZA34425] Notice of Segregation of Public Lands for the Proposed Hyder Valley Solar Energy Project in... of up to 2 years. This is for the purpose of processing one solar energy right-of-way (ROW) application submitted by Pacific Solar Investments, LLC, to construct and operate the Hyder Valley Solar...

ASSESSING OF HERBIVOROUS AND BENEFICIAL INSECTS ON SWITCHGRASS IN UKRAINE.

PubMed

Stefanovska, T; Kucherovska, S; Pisdlisnyuk, V

2014-01-01

A perennial switchgrass, (Panicum virgatum L.), (C4) that is native to North America has good potential for biomass production because of its wide geographic distribution and adaptability to diverse environmental conditions. Insects can significantly impact the yield and quality of biofuel crops. If switchgrass are to be grown on marginally arable land or in monoculture, it are likely to be plagued with herbivore pests and plant diseases at a rate that exceeds what would be expected if the plants were not stressed in this manner. This biofuel crop has been under evaluation for commercial growing in Ukraine for eight years. However, insect diversity and the potential impact of pests on biomass production of this feedstock have not been accessed yet. The objective of our study, started in 2011, is a survey of switch grass insects by trophic groups and determine species that have pest status at two sites in the Central part of Ukraine (Kiev and Poltava regions). In Poltava site we investigated the effect of nine varieties of switchgrass (lowland and upland) to insects' diversity. We assessed changes over time in the densities of major insects' trophic groups, identifying potential pests and natural enemies. Obtained results indicates that different life stages of herbivorous insects from Hymenoptera, Homoptera, Diptera and Coleoptera orders were present on switchgrass during the growing season. Our study results suggests that choice of variety has an impact on trophic groups' structure and number of insects from different orders on swicthgrass. Herbivores and beneficial insects were the only groups that showed significant differences across sampling dates. The highest population of herbivores insects we recorded on 'Alamo' variety for studied years, although herbivore diversity tended to increase on 'Shelter', 'Alamo' and 'Cave-in-Rock' during 2012 and 2013. 'Dacotah', 'Nebraska', 'Sunburst', 'Forestburg' and 'Carthage' showed the highest level of beneficial insects

Response of “Alamo” switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, Charles T.; Brice, Deanne J.; Castro, Hector F.

2011-01-01

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha -1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ±more » 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha -1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Finally, fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.« less

Bulk density and compaction behavior of knife mill chopped switchgrass,wheat straw, and corn stover

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevanan, Nehru; Womac, A.R.; Bitra, V.S.P.

2009-08-01

Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5 18.4 kg/m3 for switchgrass, 36.1 8.6 kg/m3 for wheat straw, and 52.1 10.8 kg/m3 for corn stover. Mean tapped bulk densities were 81.8 26.2 kg/m3 for switchgrass, 42.8 11.7 kg/m3 for wheat straw, and 58.9 13.4 kg/m3 for corn stover. Percentage changes in compressibility duemore » to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2 51.5 for chopped wheat straw and 42.1 117.7 for chopped corn stover within the tested consolidation pressure range of 5 120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone s model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone s model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.« less

Bulk density and compaction behavior of knife mill chopped switchgrass, wheat straw, and corn stover.

PubMed

Chevanan, Nehru; Womac, Alvin R; Bitra, Venkata S P; Igathinathane, C; Yang, Yuechuan T; Miu, Petre I; Sokhansanj, Shahab

2010-01-01

Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5+/-18.4 kg/m(3) for switchgrass, 36.1+/-8.6 kg/m(3) for wheat straw, and 52.1+/-10.8 kg/m(3) for corn stover. Mean tapped bulk densities were 81.8+/-26.2 kg/m(3) for switchgrass, 42.8+/-11.7 kg/m(3) for wheat straw, and 58.9+/-13.4 kg/m(3) for corn stover. Percentage changes in compressibility due to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2-51.5 for chopped wheat straw and 42.1-117.7 for chopped corn stover within the tested consolidation pressure range of 5-120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone's model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone's model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.

Comparative transcriptome profiling of upland (VS16) and lowland (AP13) ecotypes of switchgrass.

PubMed

Ayyappan, Vasudevan; Saha, Malay C; Thimmapuram, Jyothi; Sripathi, Venkateswara R; Bhide, Ketaki P; Fiedler, Elizabeth; Hayford, Rita K; Kalavacharla, Venu Kal

2017-01-01

Transcriptomes of two switchgrass genotypes representing the upland and lowland ecotypes will be key tools in switchgrass genome annotation and biotic and abiotic stress functional genomics. Switchgrass (Panicum virgatum L.) is an important bioenergy feedstock for cellulosic ethanol production. We report genome-wide transcriptome profiling of two contrasting tetraploid switchgrass genotypes, VS16 and AP13, representing the upland and lowland ecotypes, respectively. A total of 268 million Illumina short reads (50 nt) were generated, of which, 133 million were obtained in AP13 and the rest 135 million in VS16. More than 90% of these reads were mapped to the switchgrass reference genome (V1.1). We identified 6619 and 5369 differentially expressed genes in VS16 and AP13, respectively. Gene ontology and KEGG pathway analysis identified key genes that regulate important pathways including C4 photosynthesis, photorespiration and phenylpropanoid metabolism. A series of genes (33) involved in photosynthetic pathway were up-regulated in AP13 but only two genes showed higher expression in VS16. We identified three dicarboxylate transporter homologs that were highly expressed in AP13. Additionally, genes that mediate drought, heat, and salinity tolerance were also identified. Vesicular transport proteins, syntaxin and signal recognition particles were seen to be up-regulated in VS16. Analyses of selected genes involved in biosynthesis of secondary metabolites, plant-pathogen interaction, membrane transporters, heat, drought and salinity stress responses confirmed significant variation in the relative expression reflected in RNA-Seq data between VS16 and AP13 genotypes. The phenylpropanoid pathway genes identified here are potential targets for biofuel conversion.

Impact of harvest time and cultivar on conversion of switchgrass to bio-oils via fast pyrolysis

USDA-ARS?s Scientific Manuscript database

The study of the effects of harvest time on switchgrass (Panicum virgatum L.) biomass and bioenergy production reported herein is the final part complementing two prior studies reporting on the harvest of six switchgrass cultivars grown at three northern United States locations over three years, har...

Genomic prediction for winter survival in lowland switchgrass

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a North American native perennial warm season grass and a promising cellulosic bioenergy feedstock. It has two ecotypes – lowland and upland. The lowland ecotype has generated considerable interest because of its higher biomass compared to the upland ecotype. How...

75 FR 15453 - Central Valley Project Improvement Act, Westlands Water District Drainage Repayment Contract

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-29

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Westlands Water District Drainage Repayment Contract AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of Proposed Repayment Contract. SUMMARY: The Bureau of Reclamation will be initiating negotiations with the...

75 FR 877 - Cancellation of the South Valley Facilities Expansion Project-Clark County, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-06

... DEPARTMENT OF INTERIOR Bureau of Reclamation Cancellation of the South Valley Facilities Expansion Project-- Clark County, NV AGENCY: Bureau of Reclamation, Interior. ACTION: Cancellation of Notice of Intent to prepare the Environmental Impact Statement. SUMMARY: The Bureau of Reclamation, together with...

Glycoside hydrolase activities of thermophilic bacterial consortia adapted to switchgrass.

PubMed

Gladden, John M; Allgaier, Martin; Miller, Christopher S; Hazen, Terry C; VanderGheynst, Jean S; Hugenholtz, Philip; Simmons, Blake A; Singer, Steven W

2011-08-15

Industrial-scale biofuel production requires robust enzymatic cocktails to produce fermentable sugars from lignocellulosic biomass. Thermophilic bacterial consortia are a potential source of cellulases and hemicellulases adapted to harsher reaction conditions than commercial fungal enzymes. Compost-derived microbial consortia were adapted to switchgrass at 60°C to develop thermophilic biomass-degrading consortia for detailed studies. Microbial community analysis using small-subunit rRNA gene amplicon pyrosequencing and short-read metagenomic sequencing demonstrated that thermophilic adaptation to switchgrass resulted in low-diversity bacterial consortia with a high abundance of bacteria related to thermophilic paenibacilli, Rhodothermus marinus, and Thermus thermophilus. At lower abundance, thermophilic Chloroflexi and an uncultivated lineage of the Gemmatimonadetes phylum were observed. Supernatants isolated from these consortia had high levels of xylanase and endoglucanase activities. Compared to commercial enzyme preparations, the endoglucanase enzymes had a higher thermotolerance and were more stable in the presence of 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]), an ionic liquid used for biomass pretreatment. The supernatants were used to saccharify [C2mim][OAc]-pretreated switchgrass at elevated temperatures (up to 80°C), demonstrating that these consortia are an excellent source of enzymes for the development of enzymatic cocktails tailored to more extreme reaction conditions.

Comparative study of organosolv lignin extracted from prairie cordgrass, switchgrass and corn stover.

PubMed

Cybulska, Iwona; Brudecki, Grzegorz; Rosentrater, Kurt; Julson, James L; Lei, Hanwu

2012-08-01

Lignin extracted from prairie cordgrass, switchgrass, and corn stover (using ethyl acetate-ethanol-water organosolv pretreatment) was analyzed and characterized using several methods. These methods included analysis of purity (by determination of Klason lignin, carbohydrate, and ash contents), solubility (with several organic solvents), phenolic group analysis (ultraviolet ionization difference spectra, and nitrobenzene oxidation), and general functional group analysis (by (1)H NMR). Results showed that all the examined lignin samples were relatively pure (contained over 50% Klason lignin, less than 5% carbohydrate contamination, and less than 3% ash), but switchgrass-derived lignin was observed to be the purest. All the lignins were found to contain high amounts of phenolic groups, while switchgrass-derived lignin was the most phenolic, according to the ionization difference spectra. Nitrobenzene oxidation revealed that all the lignin samples contained available guaiacyl units in high amounts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hydrologic cost-effectiveness ratio favors switchgrass production on marginal croplands over existing grasslands

PubMed Central

Yimam, Yohannes Tadesse; Ochsner, Tyson E.; Fox, Garey A.

2017-01-01

Switchgrass (Panicum virgatum L.) has attracted attention as a promising second generation biofuel feedstock. Both existing grasslands and marginal croplands have been suggested as targets for conversion to switchgrass, but the resulting production potentials and hydrologic impacts are not clear. The objectives of this study were to model switchgrass production on existing grasslands (scenario-I) and on marginal croplands that have severe to very severe limitations for crop production (scenario-II) and to evaluate the effects on evapotranspiration (ET) and streamflow. The Soil and Water Assessment Tool (SWAT) was applied to the 1063 km2 Skeleton Creek watershed in north-central Oklahoma, a watershed dominated by grasslands (35%) and winter wheat cropland (47%). The simulated average annual yield (2002–2011) for rainfed Alamo switchgrass for both scenarios was 12 Mg ha-1. Yield varied spatially under scenario-I from 6.1 to 15.3 Mg ha-1, while under scenario-II the range was from 8.2 to 13.8 Mg ha-1. Comparison of average annual ET and streamflow between the baseline simulation (existing land use) and scenario-I showed that scenario-I had 5.6% (37 mm) higher average annual ET and 27.7% lower streamflow, representing a 40.7 million m3 yr-1 streamflow reduction. Compared to the baseline, scenario-II had only 0.5% higher ET and 3.2% lower streamflow, but some monthly impacts were larger. In this watershed, the water yield reduction per ton of biomass production (i.e. hydrologic cost-effectiveness ratio) was more than 5X greater under scenario-I than under scenario-II. These results suggest that, from a hydrologic perspective, it may be preferable to convert marginal cropland to switchgrass production rather than converting existing grasslands. PMID:28792541

Hydrologic cost-effectiveness ratio favors switchgrass production on marginal croplands over existing grasslands.

PubMed

Yimam, Yohannes Tadesse; Ochsner, Tyson E; Fox, Garey A

2017-01-01

Switchgrass (Panicum virgatum L.) has attracted attention as a promising second generation biofuel feedstock. Both existing grasslands and marginal croplands have been suggested as targets for conversion to switchgrass, but the resulting production potentials and hydrologic impacts are not clear. The objectives of this study were to model switchgrass production on existing grasslands (scenario-I) and on marginal croplands that have severe to very severe limitations for crop production (scenario-II) and to evaluate the effects on evapotranspiration (ET) and streamflow. The Soil and Water Assessment Tool (SWAT) was applied to the 1063 km2 Skeleton Creek watershed in north-central Oklahoma, a watershed dominated by grasslands (35%) and winter wheat cropland (47%). The simulated average annual yield (2002-2011) for rainfed Alamo switchgrass for both scenarios was 12 Mg ha-1. Yield varied spatially under scenario-I from 6.1 to 15.3 Mg ha-1, while under scenario-II the range was from 8.2 to 13.8 Mg ha-1. Comparison of average annual ET and streamflow between the baseline simulation (existing land use) and scenario-I showed that scenario-I had 5.6% (37 mm) higher average annual ET and 27.7% lower streamflow, representing a 40.7 million m3 yr-1 streamflow reduction. Compared to the baseline, scenario-II had only 0.5% higher ET and 3.2% lower streamflow, but some monthly impacts were larger. In this watershed, the water yield reduction per ton of biomass production (i.e. hydrologic cost-effectiveness ratio) was more than 5X greater under scenario-I than under scenario-II. These results suggest that, from a hydrologic perspective, it may be preferable to convert marginal cropland to switchgrass production rather than converting existing grasslands.

Grass invasion into switchgrass managed for biomass energy

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum) is a warm-season perennial grass and is the model herbaceous perennial bioenergy feedstock. Although it is indigenous to North American grasslands east of the Rocky Mountains and has been planted for forage and conservation purposes for more than 75 years, there is con...

Sacramento Valley, CA, USA

NASA Technical Reports Server (NTRS)

1973-01-01

The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects.

Responses of switchgrass to precipitation changes: Nonlinear and asymmetric?

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Climate changes, including chronic changes in precipitation amounts, will influence plant physiology, biomass and productivity, and soil respiration. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. Two preci...

Extraction and characterization of triglycerides from coffeeweed and switchgrass seeds as potential feedstocks for biodiesel production.

PubMed

Armah-Agyeman, Grace; Gyamerah, Michael; Biney, Paul O; Woldesenbet, Selamawit

2016-10-01

Although switchgrass has been developed as a biofuel feedstock and its potential for bioethanol and bio-oil from fast pyrolysis reported in the literature, the use of the seeds of switchgrass as a source of triglycerides for biodiesel production has not been reported. Similarly, the potential for extracting triglycerides from coffeeweed (an invasive plant of no current economic value) needs to be investigated to ascertain its potential economic use for biodiesel production. The results show that coffeeweed and switchgrass seeds contain known triglycerides which are 983 and 1000 g kg(-1) respectively of the fatty acids found in edible vegetable oils such as sunflower, corn and soybean oils. In addition, the triglyceride yields of 53-67 g kg(-1) of the seed samples are in the range of commercial oil-producing seeds such as corn (42 g kg(-1) ). The results also indicate that the two non-edible oils could be used as substitutes for edible oil for biodiesel production. In addition, the use of seeds of switchgrass for non-edible oil production (as a feedstock for the production of biodiesel) further increases the total biofuel yield when switchgrass is cultivated for use as energy feedstock for pyrolysis oil and biodiesel production. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Switchgrass (Panicum virgatum L.) genotypes differ between coastal sites and inland road corridors in the Northeastern US

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a North American grass that exhibits vast genetic diversity across its geographic range. In the Northeast, switchgrass was restricted to a narrow zone adjacent to the coastal salt marsh, but current populations inhabit inland road verges raising questions about t...

Dixie Valley Engineered Geothermal System Exploration Methodology Project, Baseline Conceptual Model Report

DOE Data Explorer

Iovenitti, Joe

2014-01-02

The Engineered Geothermal System (EGS) Exploration Methodology Project is developing an exploration approach for EGS through the integration of geoscientific data. The overall project area is 2500km2 with the Calibration Area (Dixie Valley Geothermal Wellfield) being about 170km2. The Final Scientific Report (FSR) is submitted in two parts (I and II). FSR part I presents (1) an assessment of the readily available public domain data and some proprietary data provided by terra-gen power, llc, (2) a re-interpretation of these data as required, (3) an exploratory geostatistical data analysis, (4) the baseline geothermal conceptual model, and (5) the EGS favorability/trust mapping. The conceptual model presented applies to both the hydrothermal system and EGS in the Dixie Valley region. FSR Part II presents (1) 278 new gravity stations; (2) enhanced gravity-magnetic modeling; (3) 42 new ambient seismic noise survey stations; (4) an integration of the new seismic noise data with a regional seismic network; (5) a new methodology and approach to interpret this data; (5) a novel method to predict rock type and temperature based on the newly interpreted data; (6) 70 new magnetotelluric (MT) stations; (7) an integrated interpretation of the enhanced MT data set; (8) the results of a 308 station soil CO2 gas survey; (9) new conductive thermal modeling in the project area; (10) new convective modeling in the Calibration Area; (11) pseudo-convective modeling in the Calibration Area; (12) enhanced data implications and qualitative geoscience correlations at three scales (a) Regional, (b) Project, and (c) Calibration Area; (13) quantitative geostatistical exploratory data analysis; and (14) responses to nine questions posed in the proposal for this investigation. Enhanced favorability/trust maps were not generated because there was not a sufficient amount of new, fully-vetted (see below) rock type, temperature, and stress data. The enhanced seismic data did generate a new method

Dixie Valley Engineered Geothermal System Exploration Methodology Project, Baseline Conceptual Model Report

DOE Data Explorer

Iovenitti, Joe

2014-01-02

The Engineered Geothermal System (EGS) Exploration Methodology Project is developing an exploration approach for EGS through the integration of geoscientific data. The Project chose the Dixie Valley Geothermal System in Nevada as a field laboratory site for methodology calibration purposes because, in the public domain, it is a highly characterized geothermal system in the Basin and Range with a considerable amount of geoscience and most importantly, well data. The overall project area is 2500km2 with the Calibration Area (Dixie Valley Geothermal Wellfield) being about 170km2. The project was subdivided into five tasks (1) collect and assess the existing public domain geoscience data; (2) design and populate a GIS database; (3) develop a baseline (existing data) geothermal conceptual model, evaluate geostatistical relationships, and generate baseline, coupled EGS favorability/trust maps from +1km above sea level (asl) to -4km asl for the Calibration Area at 0.5km intervals to identify EGS drilling targets at a scale of 5km x 5km; (4) collect new geophysical and geochemical data, and (5) repeat Task 3 for the enhanced (baseline + new ) data. Favorability maps were based on the integrated assessment of the three critical EGS exploration parameters of interest: rock type, temperature and stress. A complimentary trust map was generated to compliment the favorability maps to graphically illustrate the cumulative confidence in the data used in the favorability mapping. The Final Scientific Report (FSR) is submitted in two parts with Part I describing the results of project Tasks 1 through 3 and Part II covering the results of project Tasks 4 through 5 plus answering nine questions posed in the proposal for the overall project. FSR Part I presents (1) an assessment of the readily available public domain data and some proprietary data provided by Terra-Gen Power, LLC, (2) a re-interpretation of these data as required, (3) an exploratory geostatistical data analysis, (4

75 FR 69698 - Central Valley Project Improvement Act, Criteria for Developing Refuge Water Management Plans

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Central Valley Project Improvement Act, Criteria for Developing Refuge Water Management Plans AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of availability. SUMMARY: The ``Criteria for Developing Refuge Water Management Plans'' (Refuge...

Soil carbon inventories under a bioenergy crop (switchgrass): Measurement limitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, C.T. Jr.; Wullschleger, S.D.

Approximately 5 yr after planting, coarse root carbon (C) and soil organic C (SOC) inventories were compared under different types of plant cover at four switchgrass (Panicum virgatum L.) production field trials in the southeastern USA. There was significantly more coarse root C under switchgrass (Alamo variety) and forest cover than tall fescue (Festuca arundinacea Schreb.), corn (Zea mays L.), or native pastures of mixed grasses. Inventories of SOC under switchgrass were not significantly greater than SOC inventories under other plant covers. At some locations the statistical power associated with ANOVA of SOC inventories was low, which raised questions aboutmore » whether differences in SOC could be detected statistically. A minimum detectable difference (MDD) for SOC inventories was calculated. The MDD is the smallest detectable difference between treatment means once the variation, significance level, statistical power, and sample size are specified. The analysis indicated that a difference of {approx}50 mg SOC/cm{sup 2} or 5 Mg SOC/ha, which is {approx}10 to 15% of existing SOC, could be detected with reasonable sample sizes and good statistical power. The smallest difference in SOC inventories that can be detected, and only with exceedingly large sample sizes, is {approx}2 to 3%. These measurement limitations have implications for monitoring and verification of proposals to ameliorate increasing global atmospheric CO{sub 2} concentrations by sequestering C in soils.« less

The Wichita Valley irrigation project: Joseph Kemp, boosterism, and conservation in northwest Texas, 1886-1939.

PubMed

Anderson, Jahue

2011-01-01

This is the story of failure: in this case, an irrigation project that never met its boosters' expectations. Between 1880 and 1930, Wichita Falls entrepreneur Joseph Kemp dreamed of an agrarian Eden on the Texas rolling plains. Kemp promoted reclamation and conservation and envisioned the Big Wichita River Valley as the "Irrigated Valley." But the process of bringing dams and irrigation ditches to the Big Wichita River ignored knowledge of the river and local environment, which ultimately was key to making these complex systems work. The boosters faced serious ecological limitations and political obstacles in their efforts to conquer water, accomplishing only parts of the grandiose vision. Ultimately, salty waters and poor drainage doomed the project. While the livestock industry survived and the oil business thrived in the subsequent decades, the dream of idyllic irrigated farmsteads slowly disappeared.

NV PFA - Steptoe Valley

DOE Data Explorer

Jim Faulds

2015-10-29

All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

The Cynon Valley Project: Investing in the Future. Early Childhood Development: Practice and Reflections Number 12.

ERIC Educational Resources Information Center

Thomas, Alain

The Cynon Valley Project in Wales, United Kingdom, used funding from the Save the Children Fund and the Bernard van Leer Foundation to address consequences of economic decline in the two communities of Fernhill and Perthcelyn. The project's focus was on early childhood education and community development. Though starting at about the same time and…

Production of deuterated switchgrass by hydroponic cultivation

DOE PAGES

Evans, Barbara R.; Bali, Garima; Foston, Marcus B.; ...

2015-04-21

Deuterium enrichment of biological materials can potential enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO 2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controlsmore » grown with H 2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50% D 2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by 1H- and 2H-NMR. Lastly, this capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.« less

The WRKY transcription factor family and senescence in switchgrass

USDA-ARS?s Scientific Manuscript database

Background: Early aerial senescence in switchgrass (Panicum virgatum) can significantly limit biomass yields. WRKY transcription factors that can regulate senescence could be used to reprogram senescence and enhance biomass yields. Methods: All potential WRKY genes present in the version 1.0 of the...

Field-grown miR156 transgenic switchgrass reproduction, yield, global gene expression analysis, and bioconfinement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Chelsea R.; Millwood, Reginald J.; Tang, Yuhong

Genetic engineering has been effective in altering cell walls for biofuel production in the bioenergy crop, switchgrass (Panicum virgatum). However, regulatory issues arising from gene flow may prevent commercialization of engineered switchgrass in the eastern United States where the species is native. And, depending on its expression level, microRNA156 (miR156) can reduce, delay, or eliminate flowering, which may serve to decrease transgene flow. Here, in this unique field study of transgenic switchgrass that was permitted to flower, two low (T14 and T35) and two medium (T27 and T37) miR156-overexpressing 'Alamo' lines with the transgene under the control of the constitutivemore » maize (Zea mays) ubiquitin 1 promoter, along with nontransgenic control plants, were grown in eastern Tennessee over two seasons.« less

Field-grown miR156 transgenic switchgrass reproduction, yield, global gene expression analysis, and bioconfinement

DOE PAGES

Johnson, Chelsea R.; Millwood, Reginald J.; Tang, Yuhong; ...

2017-11-30

Genetic engineering has been effective in altering cell walls for biofuel production in the bioenergy crop, switchgrass (Panicum virgatum). However, regulatory issues arising from gene flow may prevent commercialization of engineered switchgrass in the eastern United States where the species is native. And, depending on its expression level, microRNA156 (miR156) can reduce, delay, or eliminate flowering, which may serve to decrease transgene flow. Here, in this unique field study of transgenic switchgrass that was permitted to flower, two low (T14 and T35) and two medium (T27 and T37) miR156-overexpressing 'Alamo' lines with the transgene under the control of the constitutivemore » maize (Zea mays) ubiquitin 1 promoter, along with nontransgenic control plants, were grown in eastern Tennessee over two seasons.« less

Sacramento Valley, CA, USA

NASA Image and Video Library

1973-06-22

SL2-04-179 (22 June 1973) --- The Sacramento Valley (40.5N, 121.5W) of California is the northern extension of the Central Valley, main agriculture region of the state. Hundreds of truck farms, vineyards and orchards can be seen throughout the length and breadth of the valley which was reclaimed from the desert by means of intensive and extensive irrigation projects. Photo credit: NASA

Switchgrass as a biofuels crop for the upper Southeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parrish, D.J.; Wolf, D.D.

1993-12-31

Switchgrass (Panicum virgatum) has been identified in DOE-sponsored studies as a widely adapted, productive herbaceous candidate for biofuels cropping. It is a perennial that has been planted using no-till procedures, and it appears to have positive effects on the soils in which it grows. We have been looking at this species as a potential fuelcrop (as well as a valuable forage) for several years. In this presentation, we note several {open_quotes}lessons learned{close_quotes} about switchgrass establishment and management as an energy crop. Data include results from recent plantings in the upper Southeast USA and from cutting management studies. Six varieties ofmore » switchgrass (Alamo, Cave-in-Rock, Kanlow, Shelter, and two breeder`s lines) varied markedly in the success of their no-till establishment at eight locations across the upper Southeast. Better weed control, which was achieved at later planting dates, seemed to be the key. Yields obtained in the establishment stands revealed that two harvests per season are more productive (by 2 to 3 Mg/ha) than one, but the date of first cutting is crucial. First cutting should be from late-June to mid-July. A two-cut system may not be economically advantageous, however. Another cutting-management study detected losses of standing biomass at the end of the growing season. As much as 15% of the above-ground biomass present in early-September was no longer harvestable in early-November. We think this loss results from translocation of dry matter to below-ground parts.« less

Tassel Removal Positively Affects Biomass Production Coupled with Significantly Increasing Stem Digestibility in Switchgrass

PubMed Central

Zhao, Chunqiao; Fan, Xifeng; Hou, Xincun; Zhu, Yi; Yue, Yuesen; Zhang, Shuang; Wu, Juying

2015-01-01

In this study, tassels of Cave-in-Rock (upland) and Alamo (lowland) were removed at or near tassel emergence to explore its effects on biomass production and quality. Tassel-removed (TR) Cave-in-Rock and Alamo both exhibited a significant (P<0.05) increase in plant heights (not including tassel length), tiller number, and aboveground biomass dry weight (10% and 12%, 30% and 13%, 13% and 18%, respectively by variety) compared to a control (CK) treatment. Notably, total sugar yields of TR Cave-in-Rock and Alamo stems increased significantly (P<0.05 or 0.01) by 19% and 19%, 21% and 14%, 52% and 18%, respectively by variety, compared to those of control switchgrass under 3 treatments by direct enzymatic hydrolysis (DEH), enzymatic hydrolysis after 1% NaOH pretreatment (EHAL) and enzymatic hydrolysis after 1% H2SO4 pretreatment (EHAC). These differences were mainly due to significantly (P<0.05 or 0.01) higher cellulose content, lower cellulose crystallinity indexes (CrI) caused by higher arabinose (Ara) substitution in xylans, and lower S/G ratio in lignin. However, the increases of nitrogen (N) and sulphur (S) concentration negatively affects the combustion quality of switchgrass aboveground biomass. This work provides information for increasing biomass production and quality in switchgrass and also facilitates the inhibition of gene dispersal of switchgrass in China. PMID:25849123

The culturable endophytic fungal communities of switchgrass grown on a coal-mining site and their effects on plant growth

PubMed Central

Amna, Amna; Opiyo, Stephen Obol

2018-01-01

Plants have a diverse endophytic microbiome that is functionally important for their growth, development, and health. In this study, the diversity and specificity of culturable endophytic fungal communities were explored in one of the most important biofuel crops, switchgrass plants (Panicum virgatum L.), which have been cultivated on a reclaimed coal-mining site for more than 20 years. The endophytic fungi were isolated from the surface-sterilized shoot (leaf and stem), root, and seed tissues of switchgrass plants and then cultured for identification. A total of 1339 fungal isolates were found and 22 operational taxonomic units (OTUs) were sequence identified by internal transcribed spacer (ITS) primers and grouped into 7 orders and 4 classes. Although a diverse range of endophytic fungi associated with switchgrass were documented, the most abundant class, order, and species were Sordariomycetes, Hypocreales, and Fusarium spp. respectively. About 86% of the isolated endophytic fungi were able to enhance the heights of the shoots; 69% could increase the shoot fresh weights; and 62% could improve the shoot dry weights after being reintroduced back into the switchgrass plants, which illustrated their functional importance. Through the Shannon Diversity Index analysis, we observed a gradation of species diversity, with shoots and roots having the similar values and seeds having a lesser value. It was observed that the switchgrass plants showing better growth performance displayed higher endophytic fungal species diversity and abundance. It was also discovered that the rhizosphere soil organic matter content was positively correlated with the fungal species diversity. All these data demonstrate the functional association of these beneficial endophytic fungi with switchgrass and their great potential in improving the switchgrass growth and biomass to benefit the biofuel industry by reducing chemical inputs and burden to the environment. PMID:29902231

The culturable endophytic fungal communities of switchgrass grown on a coal-mining site and their effects on plant growth.

PubMed

Xia, Ye; Amna, Amna; Opiyo, Stephen Obol

2018-01-01

Plants have a diverse endophytic microbiome that is functionally important for their growth, development, and health. In this study, the diversity and specificity of culturable endophytic fungal communities were explored in one of the most important biofuel crops, switchgrass plants (Panicum virgatum L.), which have been cultivated on a reclaimed coal-mining site for more than 20 years. The endophytic fungi were isolated from the surface-sterilized shoot (leaf and stem), root, and seed tissues of switchgrass plants and then cultured for identification. A total of 1339 fungal isolates were found and 22 operational taxonomic units (OTUs) were sequence identified by internal transcribed spacer (ITS) primers and grouped into 7 orders and 4 classes. Although a diverse range of endophytic fungi associated with switchgrass were documented, the most abundant class, order, and species were Sordariomycetes, Hypocreales, and Fusarium spp. respectively. About 86% of the isolated endophytic fungi were able to enhance the heights of the shoots; 69% could increase the shoot fresh weights; and 62% could improve the shoot dry weights after being reintroduced back into the switchgrass plants, which illustrated their functional importance. Through the Shannon Diversity Index analysis, we observed a gradation of species diversity, with shoots and roots having the similar values and seeds having a lesser value. It was observed that the switchgrass plants showing better growth performance displayed higher endophytic fungal species diversity and abundance. It was also discovered that the rhizosphere soil organic matter content was positively correlated with the fungal species diversity. All these data demonstrate the functional association of these beneficial endophytic fungi with switchgrass and their great potential in improving the switchgrass growth and biomass to benefit the biofuel industry by reducing chemical inputs and burden to the environment.

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination

PubMed Central

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L.; Mattes, Timothy E.

2015-01-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent and bioaccumulative. In this study we investigated bacterial communities in soil microcosms spiked with PCB 52, 77 and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal and redox cycling (i.e. sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after two weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms, and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests they play a role in PCB dechlorination therein. PMID:25820643

Microbial community analysis of switchgrass planted and unplanted soil microcosms displaying PCB dechlorination.

PubMed

Liang, Yi; Meggo, Richard; Hu, Dingfei; Schnoor, Jerald L; Mattes, Timothy E

2015-08-01

Polychlorinated biphenyls (PCBs) pose potential risks to human and environmental health because they are carcinogenic, persistent, and bioaccumulative. In this study, we investigated bacterial communities in soil microcosms spiked with PCB 52, 77, and 153. Switchgrass (Panicum virgatum) was employed to improve overall PCB removal, and redox cycling (i.e., sequential periods of flooding followed by periods of no flooding) was performed in an effort to promote PCB dechlorination. Lesser chlorinated PCB transformation products were detected in all microcosms, indicating the occurrence of PCB dechlorination. Terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis showed that PCB spiking, switchgrass planting, and redox cycling affected the microbial community structure. Putative organohalide-respiring Chloroflexi populations, which were not found in unflooded microcosms, were enriched after 2 weeks of flooding in the redox-cycled microcosms. Sequences classified as Geobacter sp. were detected in all microcosms and were most abundant in the switchgrass-planted microcosm spiked with PCB congeners. The presence of possible organohalide-respiring bacteria in these soil microcosms suggests that they play a role in PCB dechlorination therein.

Nitrogen management of switchgrass and miscanthus on marginal soils

USDA-ARS?s Scientific Manuscript database

Miscanthus × giganteus and switchgrass yield and fertilizer N requirements have been well studied in Europe and parts of the United States, but few reports have investigated their production on eroded claypan soils economically marginal for grain crops. This study was conducted to evaluate yield pot...

Topsoil depth influences switchgrass nitrogen management on claypan soils

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is an attractive forage or bioenergy crop option for eroded portions of claypan landscapes where grain crop production is marginally profitable. Topsoil depth to the claypan can vary widely within fields and little information exists on the impacts of the topsoil de...

Effect of ensiling and silage additives on biogas production and microbial community dynamics during anaerobic digestion of switchgrass.

PubMed

Zhao, Xiaoling; Liu, Jinhuan; Liu, Jingjing; Yang, Fuyu; Zhu, Wanbin; Yuan, Xufeng; Hu, Yuegao; Cui, Zongjun; Wang, Xiaofen

2017-10-01

Silage processing has a crucial positive impact on the methane yield of anaerobic treated substrates. Changes in the characteristics of switchgrass after ensiling with different additives and their effects on methane production and microbial community changes during anaerobic digestion were investigated. After ensiling (CK), methane yield was increased by 33.59% relative to that of fresh switchgrass (FS). In comparison with the CK treatment, methane production was improved by 17.41%, 13.08% and 8.72% in response to ensiling with LBr+X, LBr and X, respectively. A modified Gompertz model predicted that the optimum treatment was LBr+X, with a potential cumulative methane yield of 178.31mL/g total solids (TS) and a maximum biogas production rate of 44.39mL/g TS·d. Firmicutes and Bacteroidetes were the predominant bacteria in FS and silage switchgrass; however, the switchgrass treated with LBr+X was rich in Synergistetes, which was crucial for methane production. Copyright © 2017. Published by Elsevier Ltd.

Direct measures of mechanical energy for knife mill size reduction of switchgrass, wheat straw, and corn stover.

PubMed

Bitra, Venkata S P; Womac, Alvin R; Igathinathane, C; Miu, Petre I; Yang, Yuechuan T; Smith, David R; Chevanan, Nehru; Sokhansanj, Shahab

2009-12-01

Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be +/-0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

Natural variation in genes potentially involved in plant architecture and adaptation in switchgrass (Panicum virgatum L.).

PubMed

Bahri, Bochra A; Daverdin, Guillaume; Xu, Xiangyang; Cheng, Jan-Fang; Barry, Kerrie W; Brummer, E Charles; Devos, Katrien M

2018-06-14

Advances in genomic technologies have expanded our ability to accurately and exhaustively detect natural genomic variants that can be applied in crop improvement and to increase our knowledge of plant evolution and adaptation. Switchgrass (Panicum virgatum L.), an allotetraploid (2n = 4× = 36) perennial C4 grass (Poaceae family) native to North America and a feedstock crop for cellulosic biofuel production, has a large potential for genetic improvement due to its high genotypic and phenotypic variation. In this study, we analyzed single nucleotide polymorphism (SNP) variation in 372 switchgrass genotypes belonging to 36 accessions for 12 genes putatively involved in biomass production to investigate signatures of selection that could have led to ecotype differentiation and to population adaptation to geographic zones. A total of 11,682 SNPs were mined from ~ 15 Gb of sequence data, out of which 251 SNPs were retained after filtering. Population structure analysis largely grouped upland accessions into one subpopulation and lowland accessions into two additional subpopulations. The most frequent SNPs were in homozygous state within accessions. Sixty percent of the exonic SNPs were non-synonymous and, of these, 45% led to non-conservative amino acid changes. The non-conservative SNPs were largely in linkage disequilibrium with one haplotype being predominantly present in upland accessions while the other haplotype was commonly present in lowland accessions. Tajima's test of neutrality indicated that PHYB, a gene involved in photoperiod response, was under positive selection in the switchgrass population. PHYB carried a SNP leading to a non-conservative amino acid change in the PAS domain, a region that acts as a sensor for light and oxygen in signal transduction. Several non-conservative SNPs in genes potentially involved in plant architecture and adaptation have been identified and led to population structure and genetic differentiation of ecotypes in

Biomass production and nutrient removal by switchgrass under irrigation

USDA-ARS?s Scientific Manuscript database

Switchgrass has been identified to supply a major portion of U.S. energy needs when used as a fuel. Assessments of the export of essential plant nutrients are needed to determine impacts on soil fertility that will influence fertilizer recommendations since the nutrients contained in the above groun...

Switchgrass nitrogen response and estimated production costs on diverse sites

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) has been the principal perennial herbaceous crop investigated for bioenergy production in North America given its high production potential, relatively low input requirements, and potential suitability for use on marginal lands. Few large trials have determined swit...

Legacies in switchgrass resistance to and recovery from drought suggest that good years can sustain plants through bad years

USDA-ARS?s Scientific Manuscript database

The warm-season perennial switchgrass (Panicum virgatum) is a candidate bioenergy crop. To be successful, switchgrass production must be maintained on low-quality landscapes with minimal inputs while facing future climates that are expected to be more extreme and more variable. We propose that ant...

Model optimization of cadmium and accumulation in switchgrass (Panicum virgatum L.): potential use for ecological phytoremediation in Cd-contaminated soils.

PubMed

Wang, Quanzhen; Gu, Muyu; Ma, Xiaomin; Zhang, Hongjuan; Wang, Yafang; Cui, Jian; Gao, Wei; Gui, Jing

2015-11-01

Soil pollution with heavy metals is an increasingly serious threat to the environment, food security, and human health. Therefore, it is urgent to develop economic and highly efficient soil restoration technology for environmental improvement; phytoremediation is an option that is safe, has low cost, and is environmentally friendly. However, in selecting hyperaccumulators or tolerant plants, theories and operation technologies for optimal restoration should be satisfied. In this study, the switchgrass growth response and performance of phytoextraction under the coupling effect of Cd and pH were investigated by evaluating seed germination, seedling growth, and the Cd content in the plant to evaluate the potential use of switchgrass as a phytoremediation plant in cadmium contaminated soil. This study conducted three sets of independent experiments with five levels of Cd concentrations, including two orthogonal matrix designs of combining Cd with pH values. The results showed that switchgrass was germinated well under all treatments (Cd concentration of 0-500 μM), but the seedling growth was significantly affected by Cd and pH, as shown by multivariate regression analyses. Hormesis was found during the growth of switchgrass plants exposed to low Cd concentrations under hydroponic conditions, and switchgrass plants were capable of developing with a Cd concentration of 100-175 μM and pH of 4.1-5.9. Mild acidic conditions can enhance the ability of Cd to accumulate in switchgrass. Switchgrass was moderately tolerant to Cd and may be used as a phytoremediation plant for Cd-contaminated soils in the future. Our results also suggest that hormetic effects should be taken into consideration in the phytoremediation of Cd-contaminated soils. We discuss the physiological and biochemical mechanisms contributing to the effective application of the plant for the phytoremediation of Cd-contaminated soils.

Site preparation for switchgrass intercropping in loblolly pine plantations reduces retained trees and snags, but maintains downed woody debris

USGS Publications Warehouse

Loman, Zachary G.; Riffell, Samuel K.; Miller, Darrin A.; Martin, James A.; Vilella, Francisco

2013-01-01

Within young pine (Pinus spp.) plantations, coarse woody debris (CWD) and green trees are important habitat structures that may be impacted by the production of biofuel feedstock. Therefore, we compared site preparation procedures associated with switchgrass (Panicum virgatum L.) intercropping to determine effects on CWD and green trees in stands (n = 24) site-prepared for intercropping, with switchgrass only, or pine plantation in Mississippi, USA. Following site preparation, CWD dispersal or volume did not differ between intercropped and control stands. Intercropped stands had significantly fewer retained trees and snags. Switchgrass monocultures had no retained trees or piles and significantly fewer pieces and less volume of CWD than the other treatments. Our results suggest switchgrass intercropping may provide similar habitat quality to traditional pine plantations for wildlife species using these areas in the year following disturbance, but may provide a less suitable habitat for species that require snags. However, the relationship between snag reduction and wildlife population response in an intercropped setting is not clear and should be further investigated. Regardless, if retaining snags is a desired outcome, site preparation for switchgrass should be restricted to the interbed area where it will be cultivated as opposed to extensive debris removal from the entire site.                   

[Effect of ensilage on bioconversion of switchgrass to ethanol based on liquid hot water pretreatment].

PubMed

Wu, Wentao; Ju, Meiting; Liu, Jinpeng; Liu, Boqun

2016-04-25

Ensilage is a traditional way of preserving fresh biomass. However, in order to apply ensilage to the ethanol biorefinery, two parameters need to be evaluated: quantity and quality changes of the biomass; and its effects on bioconversion process. To study these two aspects, switchgrass harvested on three different time points (Early, mid and late fall) were used as feedstock. The early fall harvested biomass was ensiled at 5 moisture levels ranging from 30% to 70%. Silage of 40% moisture and 3 other raw switchgrass were pretreated with liquid hot water, followed by enzymatic hydrolysis as well as simultaneous saccharification and fermentation. After 21 days storage pH values of all silages decreased below 4.0 and the dry matter losses were less than 2.0%, and structural sugars contents did not change dramatically. Liquid hot water caused more hemicellulose dissolution in the silage than in unensiled switchgrass. However, ensilage also increased the risk of releasing more sugar degradation products; After enzymatic hydrolysis, silage obtained higher total glucose, xylose and galactose yields than raw materials; After simultaneous saccharification and fermentation, ethanol concentration in silage was 12.1 g/L, higher than the unensiled switchgrass (10.3 g/L, 9.7 g/L and 10.6 g/L for early, mid and late fall respectively). Our results suggest that ensilage helps increase pretreatment efficiency and sugar yield, which increases final ethanol production.

ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA. USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ FINAL PERFORMANCE EVALUATION REPORT

EPA Science Inventory

This report documents the activities performed during and the results obtained from the arsenic removal treatment technology demonstration project at an Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The objectives of the project were t...

Evaluation of switchgrass for improved biomass yield on marginal land

USDA-ARS?s Scientific Manuscript database

The national strategy is to produce bioenergy crops on marginal cropland where there will be no competition with food production. The characteristics of switchgrass (Panicum virgatum) make it an excellent candidate for sustainable biomass production on marginal land. However, few studies have evalu...

Revealing the transcriptomic complexity of switchgrass by PacBio long-read sequencing.

PubMed

Zuo, Chunman; Blow, Matthew; Sreedasyam, Avinash; Kuo, Rita C; Ramamoorthy, Govindarajan Kunde; Torres-Jerez, Ivone; Li, Guifen; Wang, Mei; Dilworth, David; Barry, Kerrie; Udvardi, Michael; Schmutz, Jeremy; Tang, Yuhong; Xu, Ying

2018-01-01

Switchgrass ( Panicum virgatum L.) is an important bioenergy crop widely used for lignocellulosic research. While extensive transcriptomic analyses have been conducted on this species using short read-based sequencing techniques, very little has been reliably derived regarding alternatively spliced (AS) transcripts. We present an analysis of transcriptomes of six switchgrass tissue types pooled together, sequenced using Pacific Biosciences (PacBio) single-molecular long-read technology. Our analysis identified 105,419 unique transcripts covering 43,570 known genes and 8795 previously unknown genes. 45,168 are novel transcripts of known genes. A total of 60,096 AS transcripts are identified, 45,628 being novel. We have also predicted 1549 transcripts of genes involved in cell wall construction and remodeling, 639 being novel transcripts of known cell wall genes. Most of the predicted transcripts are validated against Illumina-based short reads. Specifically, 96% of the splice junction sites in all the unique transcripts are validated by at least five Illumina reads. Comparisons between genes derived from our identified transcripts and the current genome annotation revealed that among the gene set predicted by both analyses, 16,640 have different exon-intron structures. Overall, substantial amount of new information is derived from the PacBio RNA data regarding both the transcriptome and the genome of switchgrass.

Impact of harvest time and switchgrass cultivar on conversion to sugars and pyrolysis oils using biochemical and thermochemical routes

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.), a perennial grass native to much of North America, is undergoing development as a dedicated energy crop. While high-biomass yield is necessary for the development of switchgrass as a bioenergy crop, composition of the biomass and nutrient content as they relate to...

National-level infrastructure and economic effects of switchgrass cofiring with coal in existing power plants for carbon mitigation.

PubMed

Morrow, William R; Griffin, W Michael; Matthews, H Scott

2008-05-15

We update a previously presented Linear Programming (LP) methodology for estimating state level costs for reducing CO2 emissions from existing coal-fired power plants by cofiring switchgrass, a biomass energy crop, and coal. This paper presents national level results of applying the methodology to the entire portion of the United States in which switchgrass could be grown without irrigation. We present incremental switchgrass and coal cofiring carbon cost of mitigation curves along with a presentation of regionally specific cofiring economics and policy issues. The results show that cofiring 189 million dry short tons of switchgrass with coal in the existing U.S. coal-fired electricity generation fleet can mitigate approximately 256 million short tons of carbon-dioxide (CO2) per year, representing a 9% reduction of 2005 electricity sector CO2 emissions. Total marginal costs, including capital, labor, feedstock, and transportation, range from $20 to $86/ton CO2 mitigated,with average costs ranging from $20 to $45/ton. If some existing power plants upgrade to boilers designed for combusting switchgrass, an additional 54 million tons of switchgrass can be cofired. In this case, total marginal costs range from $26 to $100/ton CO2 mitigated, with average costs ranging from $20 to $60/ton. Costs for states east of the Mississippi River are largely unaffected by boiler replacement; Atlantic seaboard states represent the lowest cofiring cost of carbon mitigation. The central plains states west of the Mississippi River are most affected by the boiler replacement option and, in general, go from one of the lowest cofiring cost of carbon mitigation regions to the highest. We explain the variation in transportation expenses and highlight regional cost of mitigation variations as transportation overwhelms other cofiring costs.

Biomass logistics analysis for large scale biofuel production: case study of loblolly pine and switchgrass.

PubMed

Lu, Xiaoming; Withers, Mitch R; Seifkar, Navid; Field, Randall P; Barrett, Steven R H; Herzog, Howard J

2015-05-01

The objective of this study was to assess the costs, energy consumption and greenhouse gas (GHG) emissions throughout the biomass supply chain for large scale biofuel production. Two types of energy crop were considered, switchgrass and loblolly pine, as representative of herbaceous and woody biomass. A biomass logistics model has been developed to estimate the feedstock supply system from biomass production through transportation. Biomass in the form of woodchip, bale and pellet was investigated with road, railway and waterway transportation options. Our analysis indicated that the farm or forest gate cost is lowest for loblolly pine whole tree woodchip at $39.7/dry tonne and highest for switchgrass round bale at $72.3/dry tonne. Switchgrass farm gate GHG emissions is approximately 146kgCO2e/dry tonne, about 4 times higher than loblolly pine. The optimum biomass transportation mode and delivered form are determined by the tradeoff between fixed and variable costs for feedstock shipment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Using electrical resistance probes for moisture determination in switchgrass windrows

USDA-ARS?s Scientific Manuscript database

Determining moisture levels in windrowed biomass is important for both forage producers and researchers. Energy crops such as switchgrass have been troublesome when using the standard methods set for electrical resistance meters. The objectives of this study were to i) develop the methodologies need...

Impact of switchgrass harvest time on biomass yield and conversion

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a perennial grass native to much of North America being developed as a dedicated energy crop for conversion to biofuels. Breeding efforts are focused on producing high-yielding cultivars that can maintain high yield across multiple environments, including poor so...

Comparing corn stover and switchgrass biochar: characterization and sorption properties

USDA-ARS?s Scientific Manuscript database

A switchgrass biochar (SB) produced by fast pyrolysis and a corn stover biochar (CSB) from a slow pyrolysis process were mechanically milled and characterized. Both of these biochars are very cost-effective and originate as residues from bioenergy production and the corn industry, respectively. Thes...

Influence of endophytic root bacteria on the growth, cadmium tolerance and uptake of switchgrass (Panicum virgatum L.).

PubMed

Afzal, S; Begum, N; Zhao, H; Fang, Z; Lou, L; Cai, Q

2017-08-01

This study aimed to evaluate the effect of five cadmium-tolerant endophytic plant growth-promoting bacteria (PGPB) strains on the biomass and cadmium tolerance, and accumulation of the bioenergy plant switchgrass (Panicum virgatum L.) under cadmium (Cd)-contaminated conditions. Five bacterial strains (Bj05, Le14, Ps14, So02 and Bo03) that could tolerate up to 2000 μmol l -1 CdCl 2 with a high Cd-binding capacity were isolated from plants grown in Cd-contaminated soil. These strains could promote the growth of switchgrass in the presence of 20 μmol l -1 CdCl 2 . Under Cd stress, both the root and shoot length and biomass in two switchgrass cultivars, Alamo and Cave-in-Rock (CIR), increased significantly after treatment with PGPB (P ˂ 0·05). Of the five PGPB strains, Bj05 and Le14 most effectively alleviated the Cd-induced growth inhibition of Alamo plants. Interestingly, the five PGPB strains increased Cd tolerance and decreased the accumulation and translocation factor (TF) of Cd in switchgrass when grown in the presence of 20 μmol l -1 CdCl 2 . The Cd concentrations in roots and shoots of Alamo and CIR plants were significantly reduced (P ˂ 0·05) compared with noninoculated plants. By 16S rRNA sequencing, these PGPB strains were classified as Pseudomonas putida Bj05, Pseudomonas fluorescens Ps14, and Enterobacter spp. Le14, So02 and Bo03. Inoculation with PGPB protects plants from the inhibitory effects of Cd, improves plant growth and decreases Cd concentration. These observations suggest that these strains could be used to promote growth and lower the bioavailability of Cd in switchgrass. These strains are potential candidates for the development of low Cd-accumulating switchgrass, particularly in areas of Cd contamination and pollution, and could be used efficiently for the bioremediation of contaminated soil. © 2017 The Society for Applied Microbiology.

Field Evaluation of Transgenic Switchgrass Plants Overexpressing PvMYB4 for Reduced Biomass Recalcitrance

DOE PAGES

Baxter, Holly L.; Poovaiah, Charleson R.; Yee, Kelsey L.; ...

2015-01-07

High biomass yields and minimal agronomic input requirements have made switchgrass, Panicum virgatum L., a leading candidate lignocellulosic bioenergy crop. Large-scale lignocellulosic biofuel production from such crops is limited by the difficulty to deconstruct cell walls into fermentable sugars: the recalcitrance problem. In this study, we assessed the field performance of switchgrass plants overexpressing the switchgrass MYB 4 ( PvMYB4) transcription factor gene. PvMYB 4 transgenic switchgrass can have great lignin reduction, which commensurately increases sugar release and biofuel production. Our results over two growing seasons showed that one transgenic event (out of eight) had important gains in both biofuelmore » (32% more) and biomass (63% more) at the end of the second growing season relative to non-transgenic controls. These gains represent a doubling of biofuel production per hectare, which is the highest gain reported from any field-grown modified feedstock. In contrast to this transgenic event, which had relatively low ectopic overexpression of the transgene, five of the eight transgenic events planted did not survive the first field winter. The dead plants were all high-overexpressing events that performed well in the earlier greenhouse studies. Disease susceptibility was not compromised in any transgenic events over the field experiments. These results demonstrate the power of modifying the expression of an endogenous transcription factor to improve biofuel and biomass simultaneously, and also highlight the importance of field studies for "sorting" transgenic events. In conclusion, further research is needed to develop strategies for fine-tuning temporal-spatial transgene expression in feedstocks to optimize desired phenotypes.« less

Field Evaluation of Transgenic Switchgrass Plants Overexpressing PvMYB4 for Reduced Biomass Recalcitrance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Holly L.; Poovaiah, Charleson R.; Yee, Kelsey L.

High biomass yields and minimal agronomic input requirements have made switchgrass, Panicum virgatum L., a leading candidate lignocellulosic bioenergy crop. Large-scale lignocellulosic biofuel production from such crops is limited by the difficulty to deconstruct cell walls into fermentable sugars: the recalcitrance problem. In this study, we assessed the field performance of switchgrass plants overexpressing the switchgrass MYB 4 ( PvMYB4) transcription factor gene. PvMYB 4 transgenic switchgrass can have great lignin reduction, which commensurately increases sugar release and biofuel production. Our results over two growing seasons showed that one transgenic event (out of eight) had important gains in both biofuelmore » (32% more) and biomass (63% more) at the end of the second growing season relative to non-transgenic controls. These gains represent a doubling of biofuel production per hectare, which is the highest gain reported from any field-grown modified feedstock. In contrast to this transgenic event, which had relatively low ectopic overexpression of the transgene, five of the eight transgenic events planted did not survive the first field winter. The dead plants were all high-overexpressing events that performed well in the earlier greenhouse studies. Disease susceptibility was not compromised in any transgenic events over the field experiments. These results demonstrate the power of modifying the expression of an endogenous transcription factor to improve biofuel and biomass simultaneously, and also highlight the importance of field studies for "sorting" transgenic events. In conclusion, further research is needed to develop strategies for fine-tuning temporal-spatial transgene expression in feedstocks to optimize desired phenotypes.« less

Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California's Central Valley.

PubMed

Matchett, Elliott L; Fleskes, Joseph P

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006-2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the "existing" landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Site observational work plan for the UMTRA Project site at Monument Valley, Arizona

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-09-01

The site observational work plan (SOWP) for the Monument Valley, Arizona, US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site is one of the first site-specific documents developed to achieve ground water compliance at the site. This SOWP applies information about the Monument Valley site to a regulatory compliance framework that identifies strategies that could be used to meet ground water compliance. The compliance framework was developed in the UMTRA Ground Water programmatic environmental impact statement (DOE, 1995). The DOE`s goal is to implement a cost-effective site strategy that complies with the US Environmental Protection Agencymore » (EPA) ground water standards and protects human health and the environment. The compliance strategy that emerges in the final version of the SOWP will assess potential environmental impacts and provide stakeholder a forum for review and comment. When the compliance strategy is acceptable, it will be detailed in a remedial action plan that will be subject to review by the state and/or tribe and concurrence by the US Nuclear Regulatory Commission (NRC). Information available for the preparation of this SOWP indicates active remediation is the most likely compliance strategy for the Monument Valley site. Additional data are needed to determine the most effective remediation technology.« less

Pollen-mediated gene flow from transgenic to non-transgenic switchgrass (Panicum virgatum L.) in the field.

PubMed

Millwood, Reginald; Nageswara-Rao, Madhugiri; Ye, Rongjian; Terry-Emert, Ellie; Johnson, Chelsea R; Hanson, Micaha; Burris, Jason N; Kwit, Charles; Stewart, C Neal

2017-05-02

Switchgrass is C 4 perennial grass species that is being developed as a cellulosic bioenergy feedstock. It is wind-pollinated and considered to be an obligate outcrosser. Genetic engineering has been used to alter cell walls for more facile bioprocessing and biofuel yield. Gene flow from transgenic cultivars would likely be of regulatory concern. In this study we investigated pollen-mediated gene flow from transgenic to nontransgenic switchgrass in a 3-year field experiment performed in Oliver Springs, Tennessee, U.S.A. using a modified Nelder wheel design. The planted area (0.6 ha) contained sexually compatible pollen source and pollen receptor switchgrass plants. One hundred clonal switchgrass 'Alamo' plants transgenic for an orange-fluorescent protein (OFP) and hygromycin resistance were used as the pollen source; whole plants, including pollen, were orange-fluorescent. To assess pollen movement, pollen traps were placed at 10 m intervals from the pollen-source plot in the four cardinal directions extending to 20 m, 30 m, 30 m, and 100 m to the north, south, west, and east, respectively. To assess pollination rates, nontransgenic 'Alamo 2' switchgrass clones were planted in pairs adjacent to pollen traps. In the eastward direction there was a 98% decrease in OFP pollen grains from 10 to 100 m from the pollen-source plot (Poisson regression, F1,8 = 288.38, P < 0.0001). At the end of the second and third year, 1,820 F 1 seeds were collected from pollen recipient-plots of which 962 (52.9%) germinated and analyzed for their transgenic status. Transgenic progeny production detected in each pollen-recipient plot decreased with increased distance from the edge of the transgenic plot (Poisson regression, F1,15 = 12.98, P < 0.003). The frequency of transgenic progeny detected in the eastward plots (the direction of the prevailing wind) ranged from 79.2% at 10 m to 9.3% at 100 m. In these experiments we found transgenic pollen movement and hybridization rates to be

Topsoil thickness and harvest management influence switchgrass production and profitability

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is an attractive dual use forage and/or biomass crop option for eroded or marginal soils where corn (Zea mays L.) grain production often is not profitable. Topsoil thickness, especially above soils with a claypan, relates to crop productivity and nutrient removal an...

Switchgrass Compositional Variations Arising from Spatial Distribution and Legume Intercropping

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum) is a high–yielding, second-generation feedstock that can be grown on marginal land with minimal inputs. Due to the high genetic diversity within and among cultivars of this species, there may be a great amount of genotype x environment-induced differences among seconda...

Accuracy of Genomic Prediction in Switchgrass (Panicum virgatum L.) Improved by Accounting for Linkage Disequilibrium

PubMed Central

Ramstein, Guillaume P.; Evans, Joseph; Kaeppler, Shawn M.; Mitchell, Robert B.; Vogel, Kenneth P.; Buell, C. Robin; Casler, Michael D.

2016-01-01

Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection (GS) is an attractive technology to generate rapid genetic gains in switchgrass, and meet the goals of a substantial displacement of petroleum use with biofuels in the near future. In this study, we empirically assessed prediction procedures for genomic selection in two different populations, consisting of 137 and 110 half-sib families of switchgrass, tested in two locations in the United States for three agronomic traits: dry matter yield, plant height, and heading date. Marker data were produced for the families’ parents by exome capture sequencing, generating up to 141,030 polymorphic markers with available genomic-location and annotation information. We evaluated prediction procedures that varied not only by learning schemes and prediction models, but also by the way the data were preprocessed to account for redundancy in marker information. More complex genomic prediction procedures were generally not significantly more accurate than the simplest procedure, likely due to limited population sizes. Nevertheless, a highly significant gain in prediction accuracy was achieved by transforming the marker data through a marker correlation matrix. Our results suggest that marker-data transformations and, more generally, the account of linkage disequilibrium among markers, offer valuable opportunities for improving prediction procedures in GS. Some of the achieved prediction accuracies should motivate implementation of GS in switchgrass breeding programs. PMID:26869619

Effectiveness of the Solar Panels in the Castro Valley Unified School District Based on Projected Amount of Energy to be Produced

NASA Astrophysics Data System (ADS)

Sparks, J. R.; Palmer, T. C.; Siegel, A. P.

2014-12-01

In recent years Americans have warmed to the idea of installing solar panels to their homes and businesses. These panels help reduce the cost of receiving energy from power plants that lose a lot of energy in transportation. These power plants provide energy by burning gas or coal producing emissions that add to the growing problem of pollution and global warming. In 2010 the Castro Valley Unified School District decided to add solar panels to Canyon Middle School, Castro Valley High School, and Castro Valley Adult School. We researched whether the solar panels reached their projected amount of energy (74%) for the sites where the panels were placed. The solar panels at all three sites were found to exceed these projected amounts. The solar panels at each site produce a little over 74% for the each school.

Field productivities of Switchgrass for conversion to sugars and ethanol

USDA-ARS?s Scientific Manuscript database

Switchgrass (SG, Panicum virgatum) is a warm season perennial grass being developed as a dedicated bioenergy crop. The Agricultural Research Service has recently released a new cultivar of SG named Liberty, which is a cross between Summer and Kanlow cultivars. In prior studies Liberty grown on 4 sit...

Genetic variation, population structure and linkage disequilibrium in Switchgrass with ISSR, SCoT and EST-SSR markers.

PubMed

Zhang, Yu; Yan, Haidong; Jiang, Xiaomei; Wang, Xiaoli; Huang, Linkai; Xu, Bin; Zhang, Xinquan; Zhang, Lexin

2016-01-01

To evaluate genetic variation, population structure, and the extent of linkage disequilibrium (LD), 134 switchgrass ( Panicum virgatum L.) samples were analyzed with 51 markers, including 16 ISSRs, 20 SCoTs, and 15 EST-SSRs. In this study, a high level of genetic variation was observed in the switchgrass samples and they had an average Nei's gene diversity index (H) of 0.311. A total of 793 bands were obtained, of which 708 (89.28 %) were polymorphic. Using a parameter marker index (MI), the efficiency of the three types of markers (ISSR, SCoT, and EST-SSR) in the study were compared and we found that SCoT had a higher marker efficiency than the other two markers. The 134 switchgrass samples could be divided into two sub-populations based on STRUCTURE, UPGMA clustering, and principal coordinate analyses (PCA), and upland and lowland ecotypes could be separated by UPGMA clustering and PCA analyses. Linkage disequilibrium analysis revealed an average r 2 of 0.035 across all 51 markers, indicating a trend of higher LD in sub-population 2 than that in sub-population 1 ( P  < 0.01). The population structure revealed in this study will guide the design of future association studies using these switchgrass samples.

Flowability parameters for chopped switchgrass, wheat straw and corn stover

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevanan, Nehru; Womac, A.R.; Bitra, V.S.P.

2009-02-01

A direct shear cell to measure the shear strength and flow properties of chopped switchgrass, wheat straw, and corn stover was designed, fabricated, and tested. Yield loci (r2=0.99) determined at pre-consolidation pressures of 3.80 kPa and 5.02 kPa indicated that chopped biomass followed Mohr-Coulomb failure. Normal stress significantly affected the displacement required for shear failure, as well as the friction coefficient values for all three chopped biomass types. Displacement at shear failure ranged from 30 to 80 mm, and depended on pre-consolidation pressure, normal stress, and particle size. Friction coefficient was inversely related to normal stress, and was highest formore » chopped corn stover. Also, chopped corn stover exhibited the highest angle of internal friction, unconfined yield strength, major consolidation strength, and cohesive strength, all of which indicated increased challenges in handling chopped corn stover. The measured angle of internal friction and cohesive strength indicated that chopped biomass cannot be handled by gravity alone. The measured angle of internal friction and cohesive strength were 43 and 0.75 kPa for chopped switchgrass; 44 and 0.49 kPa for chopped wheat straw; and 48 and 0.82 kPa for chopped corn stover. Unconfined yield strength and major consolidation strength used for characterization of bulk flow materials and design of hopper dimensions were 3.4 and 10.4 kPa for chopped switchgrass; 2.3 and 9.6 kPa for chopped wheat straw and 4.2 and 11.8 kPa for chopped corn stover. These results are useful for development of efficient handling, storage, and transportation systems for biomass in biorefineries.« less

Intra-Annual Changes in Biomass, Carbon, and Nitrogen Dynamics at 4-Year Old Switchgrass Field Trials in West Tennessee, USA

USDA-ARS?s Scientific Manuscript database

Switchgrass is a potential bioenergy crop that could promote soil C sequestration in some environments. We compared four switchgrass cultivars on a well-drained Alfisol to test for differences in biomass, C, and N dynamics during the fourth growing season. There was no difference (P >0.05) among cul...

Cataloging Before and After OCLC. Illinois Valley Library System OCLC Experimental Project. Report No. 3.

ERIC Educational Resources Information Center

Bills, Linda G.

A project was conducted from 1980 to 1982 to determine the costs and benefits of OCLC use in 29 small and medium-sized member libraries of the Illinois Valley Library System (IVLS). Academic, school, public, and special libraries participated by recording the time and staffing levels used for and the cost of OCLC and pre-OCLC cataloging (by…

Effects of Quality Composts and Other Organic Amendments and Their Humic and Fulvic Acid fractions on the Germination of Slickspot Peppergrass (Lepidium Papilliferum) and Switchgrass in Various Experimental Conditions

DTIC Science & Technology

2012-01-01

Figure 2. Effect of compost HAs at different concentrations on the number of germinated seeds of Shawnee switchgrass expressed as percentages of...and C/P20%) on the early growth of these switchgrass species. 2. Experimental 2.1. Germination N. 60 seeds of each switchgrass species were...the germination process. In this experiment, n. 60 seeds of each switchgrass species were previously soaked in distilled water for 12 h, successively

evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation ans a consolidated bioprocessing approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yee, Kelsey L; Rodriguez, Jr., Miguel; Tschaplinski, Timothy J

2012-01-01

Abstract Background: The inherent recalcitrance of lignocellulosic biomass is one of the major economic hurdles for the production of fuels and chemicals from biomass. Additionally, lignin is recognized as having a negative impact on enzymatic hydrolysis of biomass, and as a result much interest has been placed on modifying the lignin pathway to improve bioconversion of lignocellulosic feedstocks. Results: Previous results showed down-regulation of the caffeic acid 3-O-methyl transferase (COMT) gene in the lignin pathway yielded switchgrass (Panicum virgatum) that was more susceptible to bioconversion after dilute acid pretreatment. Here we examined the response of these plant lines to mildermore » pretreatment conditions with yeast-based SSF, CBP with Clostridium thermocellum, and fermentations with the cellulolytic extreme thermophiles, Caldicellulosiruptor bescii and Caldicellulosiruptor obsidiansis. Unlike the S. cerevisiae SSF conversions, fermentations of pretreated down-regulated COMT transgenic switchgrass with C. thermocellum showed an apparent inhibition of fermentation not observed in the wild-type switchgrass. This inhibition can be eliminated by hot water extraction of the pretreated biomass which resulted in superior conversion yield with transgenic versus wild-type switchgrass for C. thermocellum, also exceeding the yeast-based SSF yield. Further fermentation evaluation of the transgenic switchgrass indicated differential inhibition for the Caldicellulosiruptor strains, which could not be rectified by additional processing conditions. Gas chromatography-mass spectrometry metabolite profiling was used to examine the fermentation broth to elucidate the relative abundance of lignin derived aromatic compounds. The types and abundance of fermentation-derived lignin constituents varied between C. thermocellum and each of the Caldicellulosiruptor strains. Conclusions: The down-regulation of the COMT gene improves the bioconversion of switchgrass relative

Detection and characterization of the first North American mastrevirus in Switchgrass

USDA-ARS?s Scientific Manuscript database

Virus infections have the potential to reduce biomass yields in energy crops, including Panicum virgatum (switchgrass). As a first step towards managing virus-induced biomass reductions, deep sequencing was used to identify viruses associated with mosaic symptoms in switch grass, which detected thre...

Process and technoeconomic analysis of leading pretreatment technologies for lignocellulosic ethanol production using switchgrass.

PubMed

Tao, Ling; Aden, Andy; Elander, Richard T; Pallapolu, Venkata Ramesh; Lee, Y Y; Garlock, Rebecca J; Balan, Venkatesh; Dale, Bruce E; Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R; Falls, Matthew; Holtzapple, Mark T; Sierra, Rocio; Shi, Jian; Ebrik, Mirvat A; Redmond, Tim; Yang, Bin; Wyman, Charles E; Hames, Bonnie; Thomas, Steve; Warner, Ryan E

2011-12-01

Six biomass pretreatment processes to convert switchgrass to fermentable sugars and ultimately to cellulosic ethanol are compared on a consistent basis in this technoeconomic analysis. The six pretreatment processes are ammonia fiber expansion (AFEX), dilute acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide-impregnated steam explosion (SO(2)). Each pretreatment process is modeled in the framework of an existing biochemical design model so that systematic variations of process-related changes are consistently captured. The pretreatment area process design and simulation are based on the research data generated within the Biomass Refining Consortium for Applied Fundamentals and Innovation (CAFI) 3 project. Overall ethanol production, total capital investment, and minimum ethanol selling price (MESP) are reported along with selected sensitivity analysis. The results show limited differentiation between the projected economic performances of the pretreatment options, except for processes that exhibit significantly lower monomer sugar and resulting ethanol yields. Copyright © 2011 Elsevier Ltd. All rights reserved.

77 FR 42722 - Copper Valley Electric Association; Notice of Updated Environmental Analysis Preparation Schedule

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13124-002] Copper Valley...: Original License Application. b. Project No.: 13124-002. c. Applicant: Copper Valley Electric Association (Copper Valley). d. Name of Project: Allison Creek Project. e. Location: On the south side of Port Valdez...

Accuracy of genomic prediction in switchgrass ( Panicum virgatum L.) improved by accounting for linkage disequilibrium

DOE PAGES

Ramstein, Guillaume P.; Evans, Joseph; Kaeppler, Shawn M.; ...

2016-02-11

Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection (GS) is an attractive technology to generate rapid genetic gains in switchgrass, and meet the goals of a substantial displacement of petroleum use with biofuels in the near future. In this study, we empirically assessed prediction procedures for genomic selection in two different populations, consisting of 137 and 110 half-sib families of switchgrass, tested in two locations in the United States for three agronomic traits: dry matter yield, plant height,more » and heading date. Marker data were produced for the families’ parents by exome capture sequencing, generating up to 141,030 polymorphic markers with available genomic-location and annotation information. We evaluated prediction procedures that varied not only by learning schemes and prediction models, but also by the way the data were preprocessed to account for redundancy in marker information. More complex genomic prediction procedures were generally not significantly more accurate than the simplest procedure, likely due to limited population sizes. Nevertheless, a highly significant gain in prediction accuracy was achieved by transforming the marker data through a marker correlation matrix. Our results suggest that marker-data transformations and, more generally, the account of linkage disequilibrium among markers, offer valuable opportunities for improving prediction procedures in GS. Furthermore, some of the achieved prediction accuracies should motivate implementation of GS in switchgrass breeding programs.« less

Accuracy of genomic prediction in switchgrass ( Panicum virgatum L.) improved by accounting for linkage disequilibrium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramstein, Guillaume P.; Evans, Joseph; Kaeppler, Shawn M.

Switchgrass is a relatively high-yielding and environmentally sustainable biomass crop, but further genetic gains in biomass yield must be achieved to make it an economically viable bioenergy feedstock. Genomic selection (GS) is an attractive technology to generate rapid genetic gains in switchgrass, and meet the goals of a substantial displacement of petroleum use with biofuels in the near future. In this study, we empirically assessed prediction procedures for genomic selection in two different populations, consisting of 137 and 110 half-sib families of switchgrass, tested in two locations in the United States for three agronomic traits: dry matter yield, plant height,more » and heading date. Marker data were produced for the families’ parents by exome capture sequencing, generating up to 141,030 polymorphic markers with available genomic-location and annotation information. We evaluated prediction procedures that varied not only by learning schemes and prediction models, but also by the way the data were preprocessed to account for redundancy in marker information. More complex genomic prediction procedures were generally not significantly more accurate than the simplest procedure, likely due to limited population sizes. Nevertheless, a highly significant gain in prediction accuracy was achieved by transforming the marker data through a marker correlation matrix. Our results suggest that marker-data transformations and, more generally, the account of linkage disequilibrium among markers, offer valuable opportunities for improving prediction procedures in GS. Furthermore, some of the achieved prediction accuracies should motivate implementation of GS in switchgrass breeding programs.« less

Environmental sustainability of intercropping switchgrass in a loblolly pine forest

Treesearch

George Chescheir; Francois Birgand; Mohamed Youssef; Jami Nettles; Devendra Amatya

2016-01-01

A multi-institutional watershed study has been conducted since 2010 to quantify the environmental sustainability of planting switchgrass (Panicum virgatum L.) between wide rows of loblolly pine (Pinus taeda L.). The hypothesized advantage of this intercropping system is the production of biofuel feedstock to provide additional...

Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California’s Central Valley

PubMed Central

Fleskes, Joseph P.

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Projected impacts of climate, urbanization, water management, and wetland restoration on waterbird habitat in California’s Central Valley

USGS Publications Warehouse

Matchett, Elliott L.; Fleskes, Joseph

2017-01-01

The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

Life cycle analysis of switchgrass converted via pyrolysis, gasification, and fermentation

USDA-ARS?s Scientific Manuscript database

The US is promoting and developing low carbon fuel sources. Perennial bioenergy crops such as switchgrass (Panicum virgatum L.) are one viable source for low carbon transportation fuels. The objective is to determine the net greenhouse gas (GHG) emissions from different conversion methods (pyrolysi...

Ethanol yields and cell wall properties in divergently bred switchgrass genotypes

USDA-ARS?s Scientific Manuscript database

Genetic modification of herbaceous plant cell walls to increase biofuels yields from harvested biomass is a primary bioenergy research goal. The focus of much of this research has been on cell wall lignin concentration. Using switchgrass genotypes developed by divergent breeding for ruminant diges...

Structural analysis of pyrolytic lignins isolated from switchgrass fast pyrolysis oil

USDA-ARS?s Scientific Manuscript database

Structural characterization of lignin extracted from the bio-oil produced by fast pyrolysis of switchgrass (Panicum virgatum) is reported. This new information is important to understanding the utility of lignin as a chemical feedstock in a pyrolysis based biorefinery. Pyrolysis induces a variety of...

Attitudes about OCLC in Small and Medium-Sized Libraries. Illinois Valley Library System OCLC Experimental Project. Report No. 4.

ERIC Educational Resources Information Center

Bills, Linda G.; Wilford, Valerie

A project was conducted from 1980 to 1982 to determine the costs and benefits of OCLC use in 29 small and medium-sized member libraries of the Illinois Valley Library System (IVLS). Academic, school, public, and special libraries participated in the project. Based on written attitude surveys of and interviews with library directors, staff,…

Use of Optical and Imaging Techniques for Inspection of Off-Line Joule-Heated Melter at the West Valley Demonstration Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plodinec, M. J.; Jang, P-R; Long, Z.

2003-02-25

The West Valley melter has been taken out of service. Its design is the direct ancestor of the current melter design for the Hanford Waste Treatment Plant. Over its eight years of service, the West Valley melter has endured many of the same challenges that the Hanford melter will encounter with feeds that are similar to many of the Hanford double shell tank wastes. Thus, inspection of the West Valley melter prior to its disposal could provide valuable--even crucial--information to the designers of the melters to be used at the Hanford Site, particularly if quantitative information can be obtained. Themore » objective of Mississippi State University's Diagnostic Instrumentation and Analysis Laboratory's (DIAL) efforts is to develop, fabricate, and deploy inspection tools for the West Valley melter that will (i) be remotely operable in the West Valley process cell; (ii) provide quantitative information on melter refractory wear and deposits on the refractory; and (iii) indicate areas of heterogeneity (e.g., deposits) requiring more detailed characterization. A collaborative arrangement has been established with the West Valley Demonstration Project (WVDP) to inspect their melter.« less

A simple and reliable multi-gene transformation method for switchgrass.

PubMed

Ogawa, Yoichi; Shirakawa, Makoto; Koumoto, Yasuko; Honda, Masaho; Asami, Yuki; Kondo, Yasuhiro; Hara-Nishimura, Ikuko

2014-07-01

A simple and reliable Agrobacterium -mediated transformation method was developed for switchgrass. Using this method, many transgenic plants carrying multiple genes-of-interest could be produced without untransformed escape. Switchgrass (Panicum virgatum L.) is a promising biomass crop for bioenergy. To obtain transgenic switchgrass plants carrying a multi-gene trait in a simple manner, an Agrobacterium-mediated transformation method was established by constructing a Gateway-based binary vector, optimizing transformation conditions and developing a novel selection method. A MultiRound Gateway-compatible destination binary vector carrying the bar selectable marker gene, pHKGB110, was constructed to introduce multiple genes of interest in a single transformation. Two reporter gene expression cassettes, GUSPlus and gfp, were constructed independently on two entry vectors and then introduced into a single T-DNA region of pHKGB110 via sequential LR reactions. Agrobacterium tumefaciens EHA101 carrying the resultant binary vector pHKGB112 and caryopsis-derived compact embryogenic calli were used for transformation experiments. Prolonged cocultivation for 7 days followed by cultivation on media containing meropenem improved transformation efficiency without overgrowth of Agrobacterium, which was, however, not inhibited by cefotaxime or Timentin. In addition, untransformed escape shoots were completely eliminated during the rooting stage by direct dipping the putatively transformed shoots into the herbicide Basta solution for a few seconds, designated as the 'herbicide dipping method'. It was also demonstrated that more than 90 % of the bar-positive transformants carried both reporters delivered from pHKGB112. This simple and reliable transformation method, which incorporates a new selection technique and the use of a MultiRound Gateway-based binary vector, would be suitable for producing a large number of transgenic lines carrying multiple genes.

Genome-Wide Identification, Phylogeny, and Expression Analysis of ARF Genes Involved in Vegetative Organs Development in Switchgrass.

PubMed

Wang, Jianli; Wu, Zhenying; Shen, Zhongbao; Bai, Zetao; Zhong, Peng; Ma, Lichao; Pan, Duofeng; Zhang, Ruibo; Li, Daoming; Zhang, Hailing; Fu, Chunxiang; Han, Guiqing; Guo, Changhong

2018-01-01

Auxin response factors (ARFs) have been reported to play vital roles during plant growth and development. In order to reveal specific functions related to vegetative organs in grasses, an in-depth study of the ARF gene family was carried out in switchgrass ( Panicum virgatum L.), a warm-season C4 perennial grass that is mostly used as bioenergy and animal feedstock. A total of 47 putative ARF genes ( PvARFs ) were identified in the switchgrass genome (2n = 4x = 36), 42 of which were anchored to the seven pairs of chromosomes and found to be unevenly distributed. Sixteen PvARFs were predicted to be potential targets of small RNAs (microRNA160 and 167). Phylogenetically speaking, PvARFs were divided into seven distinct subgroups based on the phylogeny, exon/intron arrangement, and conserved motif distribution. Moreover, 15 pairs of PvARFs have different temporal-spatial expression profiles in vegetative organs (2nd, 3rd, and 4th internode and leaves), which implies that different PvARFs have specific functions in switchgrass growth and development. In addition, at least 14 pairs of PvARFs respond to naphthylacetic acid (NAA) treatment, which might be helpful for us to study on auxin response in switchgrass. The comprehensive analysis, described here, will facilitate the future functional analysis of ARF genes in grasses.

QTL x environment interactions and latitudinal adaptation in switchgrass (Panicum virgatum)

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum) is a polyploid C4 perennial grass that is native to North America and has been championed as a promising biofuel feedstock. It is a common member of most native prairie communities and exhibits extensive phenotypic variability and adaptation across its range, especial...

Nitrogen rate and landscape impacts on life cycle energy use and emissions from switchgrass-derived ethanol

DOE PAGES

Mbonimpa, Eric G.; Kumar, Sandeep; Owens, Vance N.; ...

2015-08-24

Switchgrass-derived ethanol has been proposed as an alternative to fossil fuels to improve sustainability of the US energy sector. In this study, life cycle analysis (LCA) was used to estimate the environmental benefits of this fuel. To better define the LCA environmental impacts associated with fertilization rates and farm-landscape topography, results from a controlled experiment were analyzed. Data from switchgrass plots planted in 2008, consistently managed with three nitrogen rates (0, 56, and 112 kg N ha –1), two landscape positions (shoulder and footslope), and harvested annually (starting in 2009, the year after planting) through 2014 were used as inputmore » into the Greenhouse gases, Regulated Emissions and Energy use in transportation (GREET) model. Simulations determined nitrogen (N) rate and landscape impacts on the life cycle energy and emissions from switchgrass ethanol used in a passenger car as ethanol–gasoline blends (10% ethanol:E10, 85% ethanol:E85s). Results indicated that E85s may lead to lower fossil fuels use (58 to 77%), greenhouse gas (GHG) emissions (33 to 82%), and particulate matter (PM2.5) emissions (15 to 54%) in comparison with gasoline. However, volatile organic compounds (VOCs) and other criteria pollutants such as nitrogen oxides (NOx), particulate matter (PM10), and sulfur dioxides (SO x) were higher for E85s than those from gasoline. Nitrogen rate above 56 kg N ha –1 yielded no increased biomass production benefits; but did increase (up to twofold) GHG, VOCs, and criteria pollutants. Lower blend (E10) results were closely similar to those from gasoline. The landscape topography also influenced life cycle impacts. Biomass grown at the footslope of fertilized plots led to higher switchgrass biomass yield, lower GHG, VOCs, and criteria pollutants in comparison with those at the shoulder position. Lastly, results also showed that replacing switchgrass before maximum stand life (10–20 years.) can further reduce the energy

Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

PubMed Central

Parrish, David J.; Wolf, Dale D.

2014-01-01

Switchgrass (Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November) and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended. PMID:25105170

Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemus, Rocky; Parrish, David J.; Wolf, Dale D.

Switchgrass ( Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November)more » and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended.« less

Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

DOE PAGES

Lemus, Rocky; Parrish, David J.; Wolf, Dale D.

2014-01-01

Switchgrass ( Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock. The objective of this study was to investigate the performance of upland and lowland switchgrass cultivars under different environments and management treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under two management regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November)more » and a split application of 100 kg N/ha/yr. Biomass yields averaged 15 Mg/ha/yr and ranged from 10 to 22 Mg/ha/yr across cultivars, managements, locations, and years. There was no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36% lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended.« less

76 FR 18542 - Copper Valley Electric Association; Notice of Scoping Document 2 and Soliciting Scoping Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13124-002] Copper Valley.... Applicant: Copper Valley Electric Association (Copper Valley) d. Name of Project: Allison Creek Project. e.... 791(a)-825(r). g. Applicant Contact: Robert A. Wilkinson, CEO, Copper Valley Electric Association, P.O...

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach.

PubMed

Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel; van Rossum, Guus; Berruti, Franco; Kersten, Sascha; Rehmann, Lars

2016-01-01

One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when compared to dried distillers grains (DDG), the main by-product of corn ethanol. Fast pyrolysis is an alternative thermal conversion technology for processing biomass. It has recently been optimized to produce a stream rich in levoglucosan, a fermentable glucose precursor for biofuel production. Additional product streams might be of value to the petrochemical industry. However, biomass heterogeneity is known to impact the composition of pyrolytic product streams, as a complex mixture of aromatic compounds is recovered with the sugars, interfering with subsequent fermentation. The present study investigates the feasibility of fast pyrolysis to produce fermentable pyrolytic glucose from two abundant lignocellulosic biomass sources in Ontario, switchgrass (potential energy crop) and corn cobs (by-product of corn industry). Demineralization of biomass removes catalytic centers and increases the levoglucosan yield during pyrolysis. The ash content of biomass was significantly decreased by 82-90% in corn cobs when demineralized with acetic or nitric acid, respectively. In switchgrass, a reduction of only 50% for both acids could be achieved. Conversely, levoglucosan production increased 9- and 14-fold in corn cobs when rinsed with acetic and nitric acid, respectively, and increased 11-fold in switchgrass regardless of the acid used. After pyrolysis, different configurations for upgrading the pyrolytic sugars were assessed and the presence of potentially inhibitory compounds was approximated at each step as double integral of the UV spectrum signal of an HPLC assay. The results showed that water extraction followed by acid hydrolysis and solvent extraction was the best upgrading strategy

Karyotype variation is indicative of subgenomic and ecotypic differentiation in switchgrass

USDA-ARS?s Scientific Manuscript database

A cytogenetic study was conducted on a dihaploid individual (2n'='2X'='18) of switchgrass to establish a chromosome karyotype. Size differences, condensation patterns, and arm-length ratios were used as identifying features and fluorescence in-situ hybridization (FISH) assigned 5S and 45S rDNA loci...

Cell Wall Composition and Underlying QTL in an F1 Pseudo-Testcross Population of Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serba, Desalegn D.; Sykes, Robert W.; Gjersing, Erica L.

Natural genetic variation for reduced recalcitrance can be used to improve switchgrass for biofuel production. A full-sib switchgrass mapping population developed by crossing a lowland genotype, AP13, and upland genotype, VS16, was evaluated at three locations (Ardmore and Burneyville, OK and Watkinsville, GA). Biomass harvested after senescence in 2009 and 2010 was evaluated at the National Renewable Energy Laboratory (NREL) for sugar release using enzymatic hydrolysis and for lignin content and syringyl/guaiacyl lignin monomer (S/G) ratio using pyrolysis molecular beam mass spectrometry (py-MBMS). Glucose and xylose release ranged from 120 to 313 and 123 to 263 mg g -1, respectively,more » while lignin content ranged from 19 to 27% of the dry biomass. Statistically significant differences were observed among the genotypes and the environments for the cell wall composition traits. Regression analysis showed that a unit increase in lignin content reduced total sugar release by an average of 10 mg g -1. Quantitative trait loci (QTL) analysis detected 9 genomic regions underlying sugar release and 14 for lignin content. The phenotypic variation explained by the individual QTL identified for sugar release ranged from 4.5 to 9.4 and for lignin content from 3.8 to 11.1%. Mapping of the QTL regions to the switchgrass genome sequence (v1.1) found that some of the QTL colocalized with genes involved in carbohydrate processing and metabolism, plant development, defense systems, and transcription factors. Finally, the markers associated with QTL can be implemented in breeding programs to efficiently develop improved switchgrass cultivars for biofuel production.« less

Cell Wall Composition and Underlying QTL in an F1 Pseudo-Testcross Population of Switchgrass

DOE PAGES

Serba, Desalegn D.; Sykes, Robert W.; Gjersing, Erica L.; ...

2016-04-23

Natural genetic variation for reduced recalcitrance can be used to improve switchgrass for biofuel production. A full-sib switchgrass mapping population developed by crossing a lowland genotype, AP13, and upland genotype, VS16, was evaluated at three locations (Ardmore and Burneyville, OK and Watkinsville, GA). Biomass harvested after senescence in 2009 and 2010 was evaluated at the National Renewable Energy Laboratory (NREL) for sugar release using enzymatic hydrolysis and for lignin content and syringyl/guaiacyl lignin monomer (S/G) ratio using pyrolysis molecular beam mass spectrometry (py-MBMS). Glucose and xylose release ranged from 120 to 313 and 123 to 263 mg g -1, respectively,more » while lignin content ranged from 19 to 27% of the dry biomass. Statistically significant differences were observed among the genotypes and the environments for the cell wall composition traits. Regression analysis showed that a unit increase in lignin content reduced total sugar release by an average of 10 mg g -1. Quantitative trait loci (QTL) analysis detected 9 genomic regions underlying sugar release and 14 for lignin content. The phenotypic variation explained by the individual QTL identified for sugar release ranged from 4.5 to 9.4 and for lignin content from 3.8 to 11.1%. Mapping of the QTL regions to the switchgrass genome sequence (v1.1) found that some of the QTL colocalized with genes involved in carbohydrate processing and metabolism, plant development, defense systems, and transcription factors. Finally, the markers associated with QTL can be implemented in breeding programs to efficiently develop improved switchgrass cultivars for biofuel production.« less

Switchgrass (Panicum virgatum) Intercropping within Managed Loblolly Pine (Pinus taeda) Does Not Affect Wild Bee Communities.

PubMed

Campbell, Joshua W; Miller, Darren A; Martin, James A

2016-11-04

Intensively-managed pine ( Pinus spp.) have been shown to support diverse vertebrate communities, but their ability to support invertebrate communities, such as wild bees, has not been well-studied. Recently, researchers have examined intercropping switchgrass ( Panicum virgatum ), a native perennial, within intensively managed loblolly pine ( P. taeda ) plantations as a potential source for cellulosic biofuels. To better understand potential effects of intercropping on bee communities, we investigated visitation of bees within three replicates of four treatments of loblolly pine in Mississippi, U.S.A.: 3-4 year old pine plantations and 9-10 year old pine plantations with and without intercropped switchgrass. We used colored pan traps to capture bees during the growing seasons of 2013 and 2014. We captured 2507 bees comprised of 18 different genera during the two-year study, with Lasioglossum and Ceratina being the most common genera captured. Overall, bee abundances were dependent on plantation age and not presence of intercropping. Our data suggests that switchgrass does not negatively impact or promote bee communities within intensively-managed loblolly pine plantations.

Development of a Bulk-Format System to Harvest, Handle, Store, and Deliver High-Tonnage Low-Moisture Switchgrass Feedstock

DOE Office of Scientific and Technical Information (OSTI.GOV)

Womac, Alvin; Groothuis, Mitch; Westover, Tyler

2013-09-24

This project evaluates and compares comprehensive feedstock logistics systems (FLS), where a FLS is defined to comprehensively span from biomass material standing in a field to conveyance of a uniform, industrial-milled product into the throat of a biomass conversion facility (BCF). Elements of the bulk-format FLS evaluated in this project include: field-standing switchgrass dry chopped into bulk format on the farm, hauled (either loose or bulk compacted) to storage, stored with confining overburden in a protective facility, reclaimed and conveyed to bulk-format discharge, bulk compacted into an ejector trailer, and conveyed as bulk flow into the BCF. In this FLSmore » evaluation, bulk storage bins served as a controlled and sensored proxy for large commercial stacks protected from moisture with a membrane cover.« less

Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

USDA-ARS?s Scientific Manuscript database

The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI) was utilized to estimate CWSI in rain-fed switchgrass (Panicum virgatum L.) usin...

Switchgrass growth and effects on biomass accumulation, moisture content, and nutrient removal

USDA-ARS?s Scientific Manuscript database

Temporal patterns of plant growth, composition, and nutrient removal impact development of models for predicting optimal harvest times of switchgrass (Panicum virgatum L.) for bioenergy. Objectives were to characterize seasonal trends in yield, tissue moisture, ash content, leaf area index (LAI), in...

Do yield and quality of big bluestem and switchgrass feedstock decline over winter?

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks for thermochemical platforms. Feedstock storage, fall harvest constraints, and environmental benefits provided by perennials are rationales for developing localized perennial feedstock...

Switchgrass ubiquitin promoter (PVUBI2) and uses thereof

DOEpatents

Stewart, C. Neal; Mann, David George James

2013-12-10

The subject application provides polynucleotides, compositions thereof and methods for regulating gene expression in a plant. Polynucleotides disclosed herein comprise novel sequences for a promoter isolated from Panicum virgatum (switchgrass) that initiates transcription of an operably linked nucleotide sequence. Thus, various embodiments of the invention comprise the nucleotide sequence of SEQ ID NO: 2 or fragments thereof comprising nucleotides 1 to 692 of SEQ ID NO: 2 that are capable of driving the expression of an operably linked nucleic acid sequence.

Evaluating Evapotranspiration of Pine Forest, Switchgrass, and Pine- Switchgrass Intercroppings using Remote Sensing and Ground-based Methods

NASA Astrophysics Data System (ADS)

Amatya, D. M.; Panda, S.; Chescheir, G. M.; Nettles, J. E.; Appelboom, T.; Skaggs, R. W.

2011-12-01

Vast areas of the land in the Southeastern United States are under pine forests managed primarily for timber and related byproducts. Evapotranspiration (ET) is the major loss in the water balance of this forest ecosystem. A long-term (1988-2008) study to evaluate hydrologic and nutrient balance during a life cycle of a pine stand was just completed. The study used both monitoring and modeling approaches to evaluate hydrologic and water quality effects of silvicultural and water management treatments on three 25 ha experimental watersheds in eastern North Carolina (NC). The research was extended in 2009 to include a dedicated energy crop, switchgrass (Panicum virgatum), by adding an adjacent 25 ha watershed. These multiple watersheds are being used to evaluate the hydrologic and water quality effects of switchgrass alone, young pine with natural understory, and young pine with switchgrass intercropping compared to the control (pine stand with a natural understory). The biofuels study has been further expanded to two other southern states, Alabama (AL) and Mississippi (MS). Each has five small watersheds (< 25 ha size) consisting of the above treatments and an additional woody biomass removal treatment. In this presentation we provide methods for estimating ET for these treatment watersheds in all three states (NC, AL, and MS) using remote sensing based spatial high resolution multispectral satellite imagery data with ground truthing, where possible, together with sensor technology. This technology is making ET parameter estimation a reality for various crops and vegetation surfaces. Slope-based vegetation indices like Normalized Difference Vegetation Index (NDVI) and Green Vegetation Index (GVI) and distance-based vegetation indices like Soil Adjusted Vegetation Index (SAVI) and Perpendicular Vegetation Index (PVI) will be developed using the R and NIR bands, vegetation density, and background soil reflectance as necessary. Landsat and high resolution aerial

Long Valley Coring Project

USGS Publications Warehouse

Sass, John; Finger, John; McConnel, Vicki

1998-01-01

In December 1997, the California Energy Commission (CEC) agreed to provide funding for Phase III continued drilling of the Long Valley Exploratory Well (LVEW) near Mammoth Lakes, CA, from its present depth. The CEC contribution of $1 million completes a funding package of $2 million from a variety of sources, which will allow the well to be cored continuously to a depth of between 11,500 and 12,500 feet. The core recovered from Phase III will be crucial to understanding the origin and history of the hydrothermal systems responsible for the filling of fractures in the basement rock. The borehole may penetrate the metamorphic roof of the large magmatic complex that has fed the volcanism responsible for the caldera and subsequent activity.

First report of Puccinia emaculata on switchgrass (Panicum virgatum L.) in Tennessee

USDA-ARS?s Scientific Manuscript database

In the spring of 2007, switchgrass accessions and cultivars Alamo, Kanlow, SL-93-2001, and NSL 2001-1 (lowland), Blackwell (upland), Grenville, Falcon, and Miami (unknown ploidy levels) were sown at the East Tennessee Research and Extension Center in Knoxville, Tennessee for evaluation and controlle...

N2 fixation of common and hairy vetches when intercropped into switchgrass

USDA-ARS?s Scientific Manuscript database

Interest in alternatives to synthetic nitrogen (N) fertilizer for switchgrass (Panicum virgatum L.) forage and bioenergy production continues to increase, and interseeding legumes into swards may be one such prospect. Common vetch (Vicia sativa L.) occurs naturally throughout the U.S. and has fewer ...

Fertilizer recommendations for switchgrass: Quantifying economic effects on quality and yield

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) is a native, perennial warm season grass that is suited for biomass production for conversion to renewable fuels as well as feed production on marginal soils. Yield responses to macro nutrients of N, P and K, have shown N to be the major driver for capturing yield p...

Association of proteomics changes with Al-sensitive root zones in switchgrass

USDA-ARS?s Scientific Manuscript database

In this paper, we report on aluminum (Al)-induced root proteomic changes in switchgrass. After growth in a hydroponic culture system supplemented with 400 uM of Al, plants began to show signs of physiological stress such as a reduction in photosynthetic rate. At this time, the basal 2-cmlong root ti...

Deciphering Natural Allelic Variation in Switchgrass for Biomass Yield and Quality Using a Nested Association Mapping Population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saha, Malay C.; Brummer, E. Charles; Kaeppler, Shawn

Switchgrass (Panicum virgatum L.) is a C4 grass with high biomass yield potential and a model species for bioenergy feedstock development. Understanding the genetic basis of quantitative traits is essential to facilitate genome-enabled breeding programs. The nested association mapping (NAM) analysis combines the best features of both bi-parental and association analyses and can provide high power and high resolution in QTL detection and will ensure significant improvements in biomass yield and quality. To develop a NAM population of switchgrass, 15 highly diverse genotypes with specific characteristics were selected from a diversity panel and crossed to a recurrent parent, AP13, amore » genotype selected for whole genome sequencing and parent of a mapping population. Ten genotypes from each of the 15 F1 families were then chain crossed. Progenies form each family were randomly selected to develop the NAM population. The switchgrass NAM population consists of a total of 2000 genotypes from 15 families. All the progenies, founder parents, F1 parents (n=2350) were evaluated in replicated field trials at Ardmore, OK and Knoxville, TN. Phenotypic data on plant height, tillering ability, regrowth, flowering time, and biomass yield were collected. Dried biomass samples were also analyzed using prediction equations of NIRS at the Noble Foundation and for lignin content, S/G ratio, and sugar release characteristics at the NREL. Genomic shotgun sequencing of 15 switchgrass NAM founder parental genomes at JGI produced 28-66 Gb high-quality sequence data. Alignment of these sequences with the reference genome, AP13 (v3.0), revealed that up to 99% of the genomic sequences mapped to the reference genome. A total of 2,149 individuals from NAM populations were sequenced by exome capture and two sets of 15 SNP matrices (one for each family) were generated. QTL associated with important traits have been identified and verified in breeding populations. The QTL detected and their

Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment

PubMed Central

Yu, Chih-Li; Deng, Qi; Dzantor, E. Kudjo; Zhou, Suping; Dennis, Sam; Sauve, Roger; Johnson, Terrance L.; Fay, Philip A.; Shen, Weijun; Luo, Yiqi

2018-01-01

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo’s growth and biomass, and that high precipitation stimulates its photosynthesis and growth. PMID:29420600

Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment.

PubMed

Hui, Dafeng; Yu, Chih-Li; Deng, Qi; Dzantor, E Kudjo; Zhou, Suping; Dennis, Sam; Sauve, Roger; Johnson, Terrance L; Fay, Philip A; Shen, Weijun; Luo, Yiqi

2018-01-01

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots (95 L) in an environmentally controlled greenhouse in Nashville, TN. Five precipitation treatments (ambient precipitation, and -50%, -33%, +33%, and +50% of ambient) were applied in a randomized complete block design with lowland "Alamo" switchgrass plants one year after they were established from tillers. The growing season progression of leaf physiology, tiller number, height, and aboveground biomass were determined each growing season. Precipitation treatments significantly affected leaf physiology, growth, and aboveground biomass. The photosynthetic rates in the wet (+50% and +33%) treatments were significantly enhanced by 15.9% and 8.1%, respectively, than the ambient treatment. Both leaf biomass and plant height were largely increased, resulting in dramatically increases in aboveground biomass by 56.5% and 49.6% in the +50% and +33% treatments, respectively. Compared to the ambient treatment, the drought (-33% and -50%) treatments did not influence leaf physiology, but the -50% treatment significantly reduced leaf biomass by 37.8%, plant height by 16.3%, and aboveground biomass by 38.9%. This study demonstrated that while switchgrass in general is a drought tolerant grass, severe drought significantly reduces Alamo's growth and biomass, and that high precipitation stimulates its photosynthesis and growth.

Analysis of projected water availability with current basin management plan, Pajaro Valley, California

NASA Astrophysics Data System (ADS)

Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

2014-11-01

The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within ;water-balance subregions; (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and

Differences and Commonalities: Farmer Stratifications in the San Luis Valley Research/Extension Project Area. ARE Research Report.

ERIC Educational Resources Information Center

Eckert, Jerry B.

A research project in the San Luis Valley of Colorado sought to isolate a few unique farm types that could become target groups for the design and implementation of agricultural research and extension programs. Questionnaires were completed by 44 of 65 farmers in one watershed area of Conejos County. Analysis revealed a complex pattern of…

Effects of site preparation for pine forest/switchgrass Intercropping on water quality

Treesearch

A. Muwamba; D. M. Amatya; H. Ssegane; G.M. Chescheir; T. Appelboom; E.W. Tollner; J. E. Nettles; M. A. Youssef; F. Birgand; R. W. Skaggs; S. Tian

2015-01-01

A study was initiated to investigate the sustainability effects of intercropping switchgrass (Panicum virgatum L.) in a loblolly pine (Pinus taeda L.) plantation. This forest-based biofuel system could possibly provide biomass from the perennial energy grass while maintaining the economics and environmental benefits of a forest...

Evaluating the impacts of landscape positions and nitrogen fertilizer rates on dissolved organic carbon on switchgrass land seeded on marginally yielding cropland.

PubMed

Lai, Liming; Kumar, Sandeep; Mbonimpa, Eric G; Hong, Chang Oh; Owens, Vance N; Neupane, Ram P

2016-04-15

Dissolved organic carbon (DOC) through leaching into the soils is another mechanism of net C loss. It plays an important role in impacting the environment and impacted by soil and crop management practices. However, little is known about the impacts of landscape positions and nitrogen (N) fertilizer rates on DOC leaching in switchgrass (Panicum virgatum L.). This experimental design included three N fertilizer rates [0 (low); 56 (medium); 112 (high) kg N ha(-1)] and three landscape positions (shoulder, backslope and footslope). Daily average DOC contents at backslope were significantly lower than that at shoulder and footslope. The DOC contents from the plots that received medium N rate were also significantly lower than the plots that received low N rates. The interactions of landscape and N rates on DOC contents were different in every year from 2009 to 2014, however, no significant consistent trend of DOC contents was observed over time. Annual average DOC contents from the plots managed with low N rate were higher than those with high N rate. These contents at the footslope were higher than that at the shoulder position. Data show that there is a moderate positive relationship between the total average DOC contents and the total average switchgrass biomass yields. Overall, the DOC contents from leachate in the switchgrass land were significantly influenced by landscape positions and N rates. The N fertilization reduced DOC leaching contents in switchgrass field. The switchgrass could retain soil and environment sustainability to some extent. These findings will assist in understanding the mechanism of changes in DOC contents with various parameters in the natural environment and crop management systems. However, use of long-term data might help to better assess the effects of above factors on DOC leaching contents and loss in the switchgrass field in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seismic calibration shots conducted in 2009 in the Imperial Valley, southern California, for the Salton Seismic Imaging Project (SSIP)

USGS Publications Warehouse

Murphy, Janice; Goldman, Mark; Fuis, Gary; Rymer, Michael; Sickler, Robert; Miller, Summer; Butcher, Lesley; Ricketts, Jason; Criley, Coyn; Stock, Joann; Hole, John; Chavez, Greg

2011-01-01

Rupture of the southern section of the San Andreas Fault, from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard facing California in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of lifelines (freeways, aqueducts, power, petroleum, and communication lines) that would bring much of southern California to a standstill. As part of the Nation's efforts to prevent a catastrophe of this magnitude, a number of projects are underway to increase our knowledge of Earth processes in the area and to mitigate the effects of such an event. One such project is the Salton Seismic Imaging Project (SSIP), which is a collaborative venture between the United States Geological Survey (USGS), California Institute of Technology (Caltech), and Virginia Polytechnic Institute and State University (Virginia Tech). This project will generate and record seismic waves that travel through the crust and upper mantle of the Salton Trough. With these data, we will construct seismic images of the subsurface, both reflection and tomographic images. These images will contribute to the earthquake-hazard assessment in southern California by helping to constrain fault locations, sedimentary basin thickness and geometry, and sedimentary seismic velocity distributions. Data acquisition is currently scheduled for winter and spring of 2011. The design and goals of SSIP resemble those of the Los Angeles Region Seismic Experiment (LARSE) of the 1990's. LARSE focused on examining the San Andreas Fault system and associated thrust-fault systems of the Transverse Ranges. LARSE was successful in constraining the geometry of the San Andreas Fault at depth and in relating this geometry to mid-crustal, flower-structure-like decollements in the Transverse Ranges that splay upward into the network of hazardous thrust faults that caused the 1971 M 6.7 San Fernando and 1987 M 5

Overexpression of gene encoding the key enzyme involved in proline-biosynthesis (PuP5CS) to improve salt tolerance in switchgrass (Panicum virgatum L.).

PubMed

Guan, Cong; Huang, Yan-Hua; Cui, Xin; Liu, Si-Jia; Zhou, Yun-Zhuan; Zhang, Yun-Wei

2018-05-25

Genetic improvement through overexpressing PuP5CS in switchgrass is feasible for enhancing plant salt stress tolerance. Switchgrass (Panicum virgatum L.) has developed into a dedicated bioenergy crop. To improve the biomass production of switchgrass grown on different types of soil, abiotic stress tolerance traits are considered for its genetic improvement. Proline accumulation is a widespread response when plants are subjected to abiotic stresses such as drought, cold and salinity. In plants, P5CS gene encodes the key regulatory enzyme that plays a crucial role in proline biosynthesis. Here, we introduced the PuP5CS gene (from Puccinellia chinampoensis) into switchgrass by Agrobacterium-mediated transformation. Transgenic lines overexpressing the PuP5CS gene showed phenotypic advantages, in leaf width, internode diameter, internode length, tiller numbers and precocious flowering under normal conditions, and the transgenic lines displayed better regenerative capacity in forming more tillers after harvest. Moreover, the PuP5CS gene enhanced the salt tolerance of transgenic switchgrass by altering a wide range of physiological responses. In accordance with the physiological results, histological analysis of cross sections through the leaf blade showed that the areas of bulliform cells and bundle sheath cells were significantly increased in PuP5CS-overexpressing leaves. The expression levels of ROS scavenging-associated genes in transgenic plants were higher than in control plants under salt stress. The results show that genetic improvement through overexpressing PuP5CS in switchgrass is feasible for enhancing plant stress tolerance.

Observation of valley-selective microwave transport in photonic crystals

NASA Astrophysics Data System (ADS)

Ye, Liping; Yang, Yuting; Hong Hang, Zhi; Qiu, Chunyin; Liu, Zhengyou

2017-12-01

Recently, the discrete valley degree of freedom has attracted extensive attention in condensed matter physics. Here, we present an experimental observation of the intriguing valley transport for microwaves in photonic crystals, including the bulk valley transport and the valley-projected edge modes along the interface separating different photonic insulating phases. For both cases, valley-selective excitations are realized by a point-like chiral source located at proper locations inside the samples. Our results are promising for exploring unprecedented routes to manipulate microwaves.

Identification and overexpression of a knotted1-like transcription factor in switchgrass ( Panicum virgatum L.) for lignocellulosic feedstock improvement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wuddineh, Wegi A.; Mazarei, Mitra; Zhang, Ji -Yi

High biomass production and wide adaptation has made switchgrass ( Panicum virgatum L.) an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Genemore » expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox) gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox) genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signaling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our findings demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.« less

Identification and overexpression of a knotted1-like transcription factor in switchgrass ( Panicum virgatum L.) for lignocellulosic feedstock improvement

DOE PAGES

Wuddineh, Wegi A.; Mazarei, Mitra; Zhang, Ji -Yi; ...

2016-04-28

High biomass production and wide adaptation has made switchgrass ( Panicum virgatum L.) an important candidate lignocellulosic bioenergy crop. One major limitation of this and other lignocellulosic feedstocks is the recalcitrance of complex carbohydrates to hydrolysis for conversion to biofuels. Lignin is the major contributor to recalcitrance as it limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars. Therefore, genetic manipulation of the lignin biosynthesis pathway is one strategy to reduce recalcitrance. Here, we identified a switchgrass Knotted1 transcription factor, PvKN1, with the aim of genetically engineering switchgrass for reduced biomass recalcitrance for biofuel production. Genemore » expression of the endogenous PvKN1 gene was observed to be highest in young inflorescences and stems. Ectopic overexpression of PvKN1 in switchgrass altered growth, especially in early developmental stages. Transgenic lines had reduced expression of most lignin biosynthetic genes accompanied by a reduction in lignin content suggesting the involvement of PvKN1 in the broad regulation of the lignin biosynthesis pathway. Moreover, the reduced expression of the Gibberellin 20-oxidase (GA20ox) gene in tandem with the increased expression of Gibberellin 2-oxidase (GA2ox) genes in transgenic PvKN1 lines suggest that PvKN1 may exert regulatory effects via modulation of GA signaling. Furthermore, overexpression of PvKN1 altered the expression of cellulose and hemicellulose biosynthetic genes and increased sugar release efficiency in transgenic lines. Our findings demonstrated that switchgrass PvKN1 is a putative ortholog of maize KN1 that is linked to plant lignification and cell wall and development traits as a major regulatory gene. Therefore, targeted overexpression of PvKN1 in bioenergy feedstocks may provide one feasible strategy for reducing biomass recalcitrance and simultaneously improving plant growth characteristics.« less

Effects of precipitation changes on switchgrass photosynthesis, growth, and biomass: A mesocosm experiment

USDA-ARS?s Scientific Manuscript database

Climate changes, including chronic changes in precipitation amounts, will influence plant physiology and growth. However, such precipitation effects on switchgrass, a major bioenergy crop, have not been well investigated. We conducted a two-year precipitation simulation experiment using large pots...

Non-targeted Colonization by the Endomycorrhizal Fungus, Serendipita vermifera, in Three Weeds Typically Co-occurring with Switchgrass

PubMed Central

Ray, Prasun; Guo, Yingqing; Kolape, Jaydeep; Craven, Kelly D.

2018-01-01

Serendipita vermifera (=Sebacina vermifera; isolate MAFF305830) is a mycorrhizal fungus originally isolated from the roots of an Australian orchid that we have previously shown to be beneficial in enhancing biomass yield and drought tolerance in switchgrass, an important bioenergy crop for cellulosic ethanol production in the United States. However, almost nothing is known about how this root-associated fungus proliferates and grows through the soil matrix. Such information is critical to evaluate the possibility of non-target effects, such as unintended spread to weedy plants growing near a colonized switchgrass plant in a field environment. A microcosm experiment was conducted to study movement of vegetative mycelia of S. vermifera between intentionally inoculated switchgrass (Panicum virgatum L.) and nearby weeds. We constructed size-exclusion microcosms to test three different common weeds, large crabgrass (Digitaria sanguinalis L.), Texas panicum (Panicum texanum L.), and Broadleaf signalgrass (Brachiaria platyphylla L.), all species that typically co-occur in Southern Oklahoma and potentially compete with switchgrass. We report that such colonization of non-target plants by S. vermifera can indeed occur, seemingly via co-mingled root systems. As a consequence of colonization, significant enhancement of growth was noted in signalgrass, while a mild increase (albeit not significant) was evident in crabgrass. Migration of the fungus seems unlikely in root-free bulk soil, as we failed to see transmission when the roots were kept separate. This research is the first documentation of non-targeted colonization of this unique root symbiotic fungus and highlights the need for such assessments prior to deployment of biological organisms in the field. PMID:29375607

First report of Tilletia pulcherrima on switchgrass (Panicum virgatum L.) in Texas

USDA-ARS?s Scientific Manuscript database

Switchgrass seed samples of cultivars ‘Blackwell’ and ‘Alamo’ from Bamert Seed Company, Muleshoe, Texas, and grown in Texas were examined microscopically for bunt fungi. Fourteen completely bunted seeds of ‘Blackwell’ and four in ‘Alamo’ were detected in 100 g samples of each. Teliospores were globo...

Genetic parameters and prediction of breeding values in switchgrass bred for bioenergy

USDA-ARS?s Scientific Manuscript database

Estimating genetic parameters is an essential step in breeding by recurrent selection to maximize genetic gains over time. This study evaluated the effects of selection on genetic variation across two successive cycles (C1 and C2) of a ‘Summer’x‘Kanlow’ switchgrass (Panicum virgatum L.) population. ...

Ground-water conditions in southern Utah Valley and Goshen Valley, Utah

USGS Publications Warehouse

Cordova, R.M.

1970-01-01

The investigation of ground-water conditions in southern Utah Valley and Goshen Valley, Utah, was made by the U. S. Geological Survey as part of a cooperative program with the Utah Department of Natural Resources, Division of Water Rights, to investigate the water resources of the State. The purposes of the investigation were to (1) determine the occurrence, recharge, discharge, movement, storage, chemical quality, and availability of ground water; (2) appraise the effects of increased withdrawal of water from wells; and (3) evaluate the effect of the Central Utah Project on the ground-water reservoir and the water supply of Utah Lake.This report presents a description of the aquifer system in the two valleys, a detailed description of the ground-water resources, and conclusions about potential development and its effect on the hydrologic conditions in the valleys. Two supplementary reports are products of the investigation. A basic-data release (Cordova, 1969) contains most of the basic data collected for the investigation, including well characteristics, drillers' logs, water levels, pumpage from wells, chemical analyses of ground and surface waters, and discharge of selected springs, drains, and streams. An interpretive report (Cordova and Mower, 1967) contains the results of a large-scale aquifer test in southern Utah Valley.

ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ SIX-MONTH EVALUATION REPORT

EPA Science Inventory

This report documents the activities performed and the results obtained from the first six months of the EPA arsenic removal technology demonstration project at the Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The main objective of the...

Smart Valley Infrastructure.

ERIC Educational Resources Information Center

Maule, R. William

1994-01-01

Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes"…

Topsoil thickness effects on corn, soybean, and switchgrass production on claypan soils

USDA-ARS?s Scientific Manuscript database

Diminished topsoil thickness or depth to claypan (DTC) is a major cause of yield and profit depression in corn (Zea mays L.) and to a lesser extent in soybean (Glycine max [L.]) production on claypan soils. Perennial grasses such as switchgrass (Panicum virgatum L.) may be more resilient to reduced ...

Identification and Characterization of microRNA319a and Its Putative Target Gene, PvPCF5, in the Bioenergy Grass Switchgrass (Panicum virgatum).

PubMed

Xie, Qi; Liu, Xue; Zhang, Yinbing; Tang, Jinfu; Yin, Dedong; Fan, Bo; Zhu, Lihuang; Han, Liebao; Song, Guilong; Li, Dayong

2017-01-01

Due to its high biomass yield, low environmental impact, and widespread adaptability to poor soils and harsh conditions, switchgrass ( Panicum virgatum L.), a warm-region perennial herbaceous plant, has attracted much attention in recent years. However, little is known about microRNAs (miRNAs) and their functions in this bioenergy grass. Here, we identified and characterized a miRNA gene, Pvi-MIR319a , encoding microRNA319a in switchgrass. Transgenic rice lines generated by overexpressing the Pvi-MIR319a precursor gene exhibited broader leaves and delayed flowering compared with the control. Gene expression analysis indicated at least four putative target genes were downregulated. Additionally, we cloned a putative target gene ( PvPCF5 ) of Pvi-MIR319a from switchgrass. PvPCF5, a TCP transcription factor, is a nuclear-localized protein with transactivation activity and control the development of leaf. Our results suggest that Pvi-MIR319a and its target genes may be used as potential genetic regulators for future switchgrass genetic improvement.

Big bluestem and switchgrass feedstock harvest timing: Nitrous oxide response to feedstock harvest timing

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks. Feedstock storage limitations, labor constraints for harvest, and environmental benefits provided by perennials are rationales for developing localized perennial feedstock as an alter...

Nitrogen and harvest impact on biomass yield of established switchgrass (Panicum virgatum L.)

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) has been identified as the model herbaceous biomass energy crop by the United States Department of Energy as it is capable of being a viable bioenergy feedstock while providing multiple environmental benefits when grown on marginal soil landscapes. Nitrogen (N) fert...

Hydraulic properties affected by topsoil thickness in switchgrass and corn-soybean cropping systems

USDA-ARS?s Scientific Manuscript database

Loss of productive topsoil by soil erosion over time can reduce the productive capacity of soil and can significantly affect soil hydraulic properties. This study evaluated the effects of reduced topsoil thickness and perennial switchgrass (Panicum virgatum L.) versus corn (Zea mays L.)/soybean [Gly...

Characterization of biobased polyurethane foams employing lignin fractionated from microwave liquefied switchgrass

Treesearch

Xingyan Huang; Cornelis F. De Hoop; Jiulong Xie; Chung-Yun Hse; Jinqiu Qi; Tingxing Hu

2017-01-01

Lignin samples fractionated from microwave liquefied switchgrass were applied in the preparation of semirigid polyurethane (PU) foams without purification.The objective of this study was to elucidate the influence of lignin in the PU matrix on themorphological, chemical, mechanical, and thermal properties of thePU foams.The scanning electron microscopy (SEM) images...

Effect of in Vivo Deuteration on Structure of Switchgrass Lignin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Xianzhi; Evans, Barbara R.; Yoo, Chang Geun

Biomass deuteration is an effective engineering method that can be used to provide key insights into understanding of biomass recalcitrance and the complex biomass conversion process. In this study, production of deuterated switchgrass was accomplished by growing the plants in 50% D 2O under hydroponic conditions in a perfusion chamber. Cellulolytic enzyme lignin was isolated from deuterated switchgrass, characterized by Fourier transform infrared (FTIR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) and compared with its protiated control sample to determine the effect of in vivo deuteration on the chemical structure of lignin. FTIR results showed that D 2Omore » can be taken up by the roots and transported to the leaves, and deuterium was subsequently incorporated into hydroxyl and alkyl groups in the plant and its lignin through photosynthesis. According to GPC results, deuterated lignin had slightly higher molecular weight, presumably due to isotope effects. 31P and heteronuclear single quantum coherence (HSQC) NMR results revealed that lignin in the deuterated biomass preserved its native physicochemical characteristics. Finally, the conserved characteristics of the deuterated lignin show its great potential applications for structural and dynamic studies of lignocellulose by techniques such as neutron scattering.« less

Effect of in Vivo Deuteration on Structure of Switchgrass Lignin

DOE PAGES

Meng, Xianzhi; Evans, Barbara R.; Yoo, Chang Geun; ...

2017-07-27

Biomass deuteration is an effective engineering method that can be used to provide key insights into understanding of biomass recalcitrance and the complex biomass conversion process. In this study, production of deuterated switchgrass was accomplished by growing the plants in 50% D 2O under hydroponic conditions in a perfusion chamber. Cellulolytic enzyme lignin was isolated from deuterated switchgrass, characterized by Fourier transform infrared (FTIR), gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) and compared with its protiated control sample to determine the effect of in vivo deuteration on the chemical structure of lignin. FTIR results showed that D 2Omore » can be taken up by the roots and transported to the leaves, and deuterium was subsequently incorporated into hydroxyl and alkyl groups in the plant and its lignin through photosynthesis. According to GPC results, deuterated lignin had slightly higher molecular weight, presumably due to isotope effects. 31P and heteronuclear single quantum coherence (HSQC) NMR results revealed that lignin in the deuterated biomass preserved its native physicochemical characteristics. Finally, the conserved characteristics of the deuterated lignin show its great potential applications for structural and dynamic studies of lignocellulose by techniques such as neutron scattering.« less

Analysis of projected water availability with current basin management plan, Pajaro Valley, California

USGS Publications Warehouse

Hanson, Randall T.; Lockwood, Brian; Schmid, Wolfgang

2014-01-01

The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000–2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery

Projected Changes in Seasonal Mean Temperature and Rainfall (2011-2040) in Cagayan Valley, Philippines

NASA Astrophysics Data System (ADS)

Basconcillo, J. Q.; Lucero, A. J. R.; Solis, A. S.; Kanamaru, H.; Sandoval, R. S.; Bautista, E. U.

2014-12-01

Among Filipinos, a meal is most often considered incomplete without rice. There is a high regard for rice in the entire archipelago that in 2012, the country's rice production was accounted to more than 18 million tons with an equivalent harvested area of 4.7 million hectares. This means that from the 5.4 million hectares of arable land in the Philippines, 11 percent are found and being utilized for rice production in Cagayan Valley (CV). In the same year, more than 13 percent of the country's total annual rice production was produced in CV. Rice production also provides employment to 844,000 persons (out of 1.4 million persons) which suggest that occupation and livelihood in Cagayan Valley are strongly anchored in rice production. These figures outline the imaginable vulnerability of rice production in CV amidst varying issues such as land conversion, urbanization, increase in population, retention of farming households, and climate change. While all these issues are of equal importance, this paper is directed towards the understanding the projected changes in seasonal rainfall and mean temperature (2011-2040). It is envisioned by this study that a successful climate change adaptation starts with the provision of climate projections hence this paper's objective to investigate on the changes in climate patterns and extreme events. Projected changes are zonally limited to the Provinces of Cagayan, Isabela, Nueva Vizcaya, and Quirino based on the statistical downscaling of three global climate models (BCM2, CNCM3, and MPEH5) and two emission scenarios (A1B and A2). With the idea that rainfall and temperature varies with topography, the AURELHY technique was utilized in interpolating climate projections. Results obtained from the statistical downscaling showed that there will be significant climate changes from 2011-2040 in terms of rainfall and mean temperature. There are also indications of increasing frequency of extreme 24-hour rainfall and number of dry days

Sodium hydroxide pretreatment of genetically modified switchgrass for improved enzymatic release of sugars

USDA-ARS?s Scientific Manuscript database

Overcoming biomass recalcitrance to biological conversion has been the focus of enormous research efforts in the cellulosic biofuel area in the past decades. In this study, Alamo switchgrass was genetically transformed to suppress the expression of 4-coumarate-CoA ligase (4CL). The transgenic plants...

Targeted mutagenesis in tetraploid switchgrass (Panicum virgatum L.) using CRISPR/Cas9.

PubMed

Liu, Yang; Merrick, Paul; Zhang, Zhengzhi; Ji, Chonghui; Yang, Bing; Fei, Shui-Zhang

2018-02-01

The CRISPR/Cas9 system has become a powerful tool for targeted mutagenesis. Switchgrass (Panicum virgatum L.) is a high yielding perennial grass species that has been designated as a model biomass crop by the U.S. Department of Energy. The self-infertility and high ploidy level make it difficult to study gene function or improve germplasm. To overcome these constraints, we explored the feasibility of using CRISPR/Cas9 for targeted mutagenesis in a tetraploid cultivar 'Alamo' switchgrass. We first developed a transient assay by which a non-functional green-fluorescent protein gene containing a 1-bp frameshift insertion in its 5' coding region was successfully mutated by a Cas9/sgRNA complex resulting in its restored function. Agrobacterium-mediated stable transformation of embryogenic calli derived from mature caryopses averaged a 3.0% transformation efficiency targeting the genes of teosinte branched 1(tb1)a and b and phosphoglycerate mutase (PGM). With a single construct containing two sgRNAs targeting different regions of tb1a and tb1b genes, primary transformants (T0) containing CRISPR/Cas9-induced mutations were obtained at frequencies of 95.5% (tb1a) and 11% (tb1b), respectively, with T0 mutants exhibiting increased tiller production. Meanwhile, a mutation frequency of 13.7% was obtained for the PGM gene with a CRISPR/Cas9 construct containing a single sgRNA. Among the PGM T0 mutants, six are heterozygous and one is homozygous for a 1-bp deletion in the target region with no apparent phenotypical alterations. We show that CRISPR/Cas9 system can generate targeted mutagenesis effectively and obtain targeted homozygous mutants in T0 generation in switchgrass, circumventing the need of inbreeding. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Switchgrass (Panicum virgatum L.) Intraspecific Variation and Thermotolerance Classification Using in Vitro Seed Germination Assay

DOE PAGES

Seepaul, Ramdeo; Macoon, Bisoondat; Reddy, K. Raja; ...

2011-01-01

Cardinal temperatures for plant processes have been used for thermotolerance screening of genotypes, geoclimatic adaptability determination and phenological prediction. Current simulation models for switchgrass (Panicum virgatum L.) utilize single cardinal temperatures across genotypes for both vegetative and reproductive processes although in-tra-specific variation exists among genotypes. An experiment was conducted to estimate the cardinal temperatures for seed germination of 14 diverse switchgrass genotypes and to classify genotypes for temperature tolerance. Stratified seeds of each genotype were germinated at eight constant temperatures from 10 °C to 45 °C under a constant light intensity of 35 μmol m -2s -1 for 12 hdmore » -1. Germination was recorded at 6-h intervals in all treatments. Maximum seed germination (MSG) and germination rate (GR), estimated by fitting Sigmoidal function to germination-time series data, varied among genotypes. Quadratic and bilinear models best described the MSG and GR responses to temperature, respectively. The mean cardinal temperatures, T min, T opt, and T max, were 8.1, 26.6, and 45.1 °C for MSG and 11.1, 33.1, and 46.0 °C for GR, respectively. Cardinal temperatures for MSG and GR; however, varied significantly among genotypes. Genotypes were classified as sensitive (Cave-in-Rock, Dacotah, Expresso, Forestburg, Kanlow, Sunburst, Trailblazer, and Tusca), intermediate (Alamo, Blackwell, Carthage, Shawnee, and Shelter) and tolerant (Summer) to high temperature based on cumulative temperature response index (CTRI) estimated by summing individual response indices estimated from the MSG and GR cardinal temperatures. Similarly, genotypes were also classified as sensitive (Alamo, Blackwell, Carthage, Dacotah, Shawnee, Shelter and Summer), moderately sensitive (Cave-in-rock, Forestburg, Kanlow, Sunburst, and Tusca), moderately tolerant (Trailblazer), and tolerant (Expresso) to low temperatures. The cardinal temperature estimates

30 years of progress toward increased biomass yield of switchgrass and big bluestem

USDA-ARS?s Scientific Manuscript database

Breeding to improved biomass production of switchgrass and big bluestem for conversion to bioenergy began in 1992. The purpose of this study was (1) to develop a platform for uniform regional testing of cultivars and experimental populations for these species and (2) to estimate the gains made by br...

ASSESSING TRANSBOUNDARY INFLUENCES IN THE LOWER RIO GRANDE VALLEY (COMMUNITY SUMMARY)

EPA Science Inventory

The Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was done to determine if movement of air pollutants across the U.S.-Mexico border was occurring in the Lower Rio Grande Valley (hereinafter called "the Valley") and, if so, the extent. The study w...

Quantitative trait loci mapping for flowering time in a switchgrass pseudo-F2 population

USDA-ARS?s Scientific Manuscript database

Flowering is an important developmental event in switchgrass (Panicum virgatum) because the onset of flowering causes the cessation of vegetative growth and biomass accumulation. The objective of this study was to generate a linkage map using single nucleotide polymorphism (SNP) markers to identify ...

Toxicity of coal fly ash (CFA) and toxicological response of switchgrass in mycorrhiza-mediated CFA-soil admixtures.

PubMed

Awoyemi, Olushola M; Dzantor, E Kudjo

2017-10-01

Increasing support for the use of Coal fly ash (CFA) in agriculture has necessitated a better understanding of the effects of the CFA in various cropping schemes. Experiments were conducted to assess mutagenic response of a mutant strain of Salmonella enterica serovar Typhimurium (TA100) to varying concentrations of CFA-water extracts, determine oxidative stress in switchgrass (Panicum virgatum L.) at varying levels of CFA-soil admixtures, and evaluate mycorrhiza-mediated modulation of oxidative stress responses of CFA-grown switchgrass. The TA100 exposed to 0%, 5%, 10%, 15%, 20% and 25% (w/v) CFA-water extracts elicited significant (p < 0.05) mutagenic responses at 20% and 25% extract levels but not below the 15% level. In greenhouse pot experiment, CFA-soil admixtures at 7.5% and 15% (w/w) significantly (p < 0.05) decreased the activities of superoxide dismutase (SOD) by 19.1% and 28.3% respectively, compared to control soil (0% w/w CFA/soil). Under the same conditions, activities of glutathione peroxidase (GPx) decreased by 75.9% and 66.9%. In contrast to the antioxidant enzyme activities, levels of malondialdehyde (MDA) an indicator of lipid peroxidation increased significantly (p < 0.05) by 30.49% and 38.38%. Inoculation of 7.5% and 15% CFA-soil admixtures with arbuscular mycorrhizal fungi (AMF), Rhizophaga clarus enhanced the activities of both SOD and GPx in the switchgrass, while it significantly (p < 0.05) reduced the levels of MDA. The study demonstrated that incorporation of CFA (at concentrations considered to be non-mutagenic against TA100) as soil amendment produced concentration-dependent oxidative stress responses in switchgrass; however, inoculation of the CFA-soil admixtures with AMF significantly modulated the oxidative stress responses. Copyright © 2017 Elsevier Inc. All rights reserved.

Gas exchange and stand-level estimates of water use and gross primary productivity in an experimental pine and switchgrass intercrop forestry system on the Lower Coastal Plain of North Carolina, U.S.A

Treesearch

Janine M. Albaugha; Jean-Christophe Domeca; Chris A. Maier; Eric B. Sucre; Zakiya H. Leggett; John S. King

2014-01-01

Despite growing interest in using switchgrass (Panicum virgatum L.) as a biofuel, there are limiteddata on the physiology of this species and its effect on stand water use and carbon (C) assimilationwhen grown as a forest intercrop for bioenergy. Therefore, we quantified gas exchange rates of switch-grass within intercropped plots and in pure switchgrass plots during...

Predicted harvest time effects on switchgrass moisture content, nutrient concentration, yield, and profitability

USDA-ARS?s Scientific Manuscript database

Production costs change with harvest date of switchgrass (Panicum virgatum L.) as a result of nutrient recycling and changes in yield of this perennial crop. This study examines the range of cost of production from an early, yield-maximizing harvest date to a late winter harvest date at low moisture...

Evaluation of the groundwater flow model for southern Utah and Goshen Valleys, Utah, updated to conditions through 2011, with new projections and groundwater management simulations

USGS Publications Warehouse

Brooks, Lynette E.

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Southern Utah Valley Municipal Water Association, updated an existing USGS model of southern Utah and Goshen Valleys for hydrologic and climatic conditions from 1991 to 2011 and used the model for projection and groundwater management simulations. All model files used in the transient model were updated to be compatible with MODFLOW-2005 and with the additional stress periods. The well and recharge files had the most extensive changes. Discharge to pumping wells in southern Utah and Goshen Valleys was estimated and simulated on an annual basis from 1991 to 2011. Recharge estimates for 1991 to 2011 were included in the updated model by using precipitation, streamflow, canal diversions, and irrigation groundwater withdrawals for each year. The model was evaluated to determine how well it simulates groundwater conditions during recent increased withdrawals and drought, and to determine if the model is adequate for use in future planning. In southern Utah Valley, the magnitude and direction of annual water-level fluctuation simulated by the updated model reasonably match measured water-level changes, but they do not simulate as much decline as was measured in some locations from 2000 to 2002. Both the rapid increase in groundwater withdrawals and the total groundwater withdrawals in southern Utah Valley during this period exceed the variations and magnitudes simulated during the 1949 to 1990 calibration period. It is possible that hydraulic properties may be locally incorrect or that changes, such as land use or irrigation diversions, occurred that are not simulated. In the northern part of Goshen Valley, simulated water-level changes reasonably match measured changes. Farther south, however, simulated declines are much less than measured declines. Land-use changes indicate that groundwater withdrawals in Goshen Valley are possibly greater than estimated and simulated. It is also possible that irrigation

Valley-polarized quantum transport generated by gauge fields in graphene

NASA Astrophysics Data System (ADS)

Settnes, Mikkel; Garcia, Jose H.; Roche, Stephan

2017-09-01

We report on the possibility to simultaneously generate in graphene a bulk valley-polarized dissipative transport and a quantum valley Hall effect by combining strain-induced gauge fields and real magnetic fields. Such unique phenomenon results from a ‘resonance/anti-resonance’ effect driven by the superposition/cancellation of superimposed gauge fields which differently affect time reversal symmetry. The onset of a valley-polarized Hall current concomitant to a dissipative valley-polarized current flow in the opposite valley is revealed by a {{e}2}/h Hall conductivity plateau. We employ efficient linear scaling Kubo transport methods combined with a valley projection scheme to access valley-dependent conductivities and show that the results are robust against disorder.

Soil and variety effects on energy use and carbon emissions associated with switchgrass-based ethanol production in Mississippi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woli, Prem; Paz, Joel O.; Baldwin, Brian S.

2012-06-29

High biomass production potential, wide adaptability, low input requirement, and low environmental risk make switchgrass an economically and ecologically viable energy crop.The inherent variablity in switchgrass productivity due to variations in soil and variety could affect the sustainability and eco-friendliness of switchgrass-based ethanol production. This study examined the soil and variety effects on these variables. Three locations in Mississippi were selected based on latitude and potential acreage. Using ALMANAC, switchgrass biomass yields were simulated for several scenarios of soils and varities. The simulated yields were fed to IBSAL to compute energy use and CO2 emissions in various operations in themore » biomass supply From the energy and emissions values, the sustainability and eco-friendliness of ethanol production were determined using net energy value (NEV) and carbon credit balance (CCB) as indicators, respectively. Soil and variety effects on NEV and CCB were analyzed using the Kruskal-Wallis test. Results showed significant differences in NEV and CCB across soils and varieties. Both NEV and CCB increased in the direction of heavier to lighter soils and on the order of north-upland , south-upland, north-lowland, and south-lowland varieties. Only north-upland and south-lowland varieties were significantly significantly different because they were different in both cytotype and ecotype. Gaps between lowland and upland varieties were smaller in a dry year than in a wet year. The NEV and CCB increased in the direction of dry to wet year. From south to north, they decreased for lowland cytotypes but increased for upland cytotypes. Thus, the differences among varieties decreased northwards.« less

Switchgrass composition and yield response to alternative soil amendments under intensified heat and drought conditions

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum L.) and guinea grass (Panicum maximum Jacq.) have been proposed as sustainable alternatives to fossil fuels in temperate and tropical environments, respectively; although still requiring non-renewable inputs, notably, fertilizer-nitrogen (N). Furthermore, climate change...

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Shiyu; Kaeppler, Shawn M.; Vogel, Kenneth P.

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system or to volatile fatty acids in a livestock production system is strongly and negatively influenced by lignification of cell walls. This study detects specific loci that exhibit selection signatures across switchgrass breeding populations that differ in in vitro dry matter digestibility (IVDMD), ethanol yield, and lignin concentration. Allele frequency changes in candidate genes were used to detect loci under selection. Out of the 183 polymorphisms identified in the four candidate genes, twenty-five loci in the intron regions and four locimore » in coding regions were found to display a selection signature. All loci in the coding regions are synonymous substitutions. Selection in both directions were observed on polymorphisms that appeared to be under selection. Genetic diversity and linkage disequilibrium within the candidate genes were low. The recurrent divergent selection caused excessive moderate allele frequencies in the cycle 3 reduced lignin population as compared to the base population. As a result, this study provides valuable insight on genetic changes occurring in short-term selection in the polyploid populations, and discovered potential markers for breeding switchgrass with improved biomass quality.« less

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

DOE PAGES

Chen, Shiyu; Kaeppler, Shawn M.; Vogel, Kenneth P.; ...

2016-11-28

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system or to volatile fatty acids in a livestock production system is strongly and negatively influenced by lignification of cell walls. This study detects specific loci that exhibit selection signatures across switchgrass breeding populations that differ in in vitro dry matter digestibility (IVDMD), ethanol yield, and lignin concentration. Allele frequency changes in candidate genes were used to detect loci under selection. Out of the 183 polymorphisms identified in the four candidate genes, twenty-five loci in the intron regions and four locimore » in coding regions were found to display a selection signature. All loci in the coding regions are synonymous substitutions. Selection in both directions were observed on polymorphisms that appeared to be under selection. Genetic diversity and linkage disequilibrium within the candidate genes were low. The recurrent divergent selection caused excessive moderate allele frequencies in the cycle 3 reduced lignin population as compared to the base population. As a result, this study provides valuable insight on genetic changes occurring in short-term selection in the polyploid populations, and discovered potential markers for breeding switchgrass with improved biomass quality.« less

Water quality effects of switchgrass intercropping on pine forest in Coastal North Carolina.

Treesearch

Augustine Muwamba; Devendra Amatya; George M Chescheir; Jamie Nettles; Timothy Appelboom; Herbert Ssegane; Ernest Tollner; Mohamed Youssef; Francois Birgand; R. Wayne Skaggs; Shiying Tian

2017-01-01

Interplanting a cellulosic bioenergy crop (switchgrass, Panicum virgatum L.) between loblolly pine (Pinus taeda L.) rows could potentially provide a sustainable source of bio-feedstock without competing for land currently in food production. The objectives of this study were to: (1) quantify the concentrations and loads of drainage water nitrogen (N) and phosphorus (...

Structure of the active rift zone and margins of the northern Imperial Valley from Salton Seismic Imaging Project (SSIP) data

NASA Astrophysics Data System (ADS)

Livers, A.; Han, L.; Delph, J. R.; White-Gaynor, A. L.; Petit, R.; Hole, J. A.; Stock, J. M.; Fuis, G. S.

2012-12-01

First-arrival refraction data were used to create a seismic velocity model of the upper crust across the actively rifting northern Imperial Valley and its margins. The densely sampled seismic refraction data were acquired by the Salton Seismic Imaging Project (SSIP) , which is investigating rift processes in the northern-most rift segment of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. A 95-km long seismic line was acquired across the northern Imperial Valley, through the Salton Sea geothermal field, parallel to the five Salton Butte volcanoes and perpendicular to the Brawley Seismic Zone and major strike-slip faults. Nineteen explosive shots were recorded with 100 m seismometer spacing across the valley and with 300-500 m spacing into the adjacent ranges. First-arrival travel times were picked from shot gathers along this line and a seismic velocity model was produced using tomographic inversion. Sedimentary basement and seismic basement in the valley are interpreted to be sediment metamorphosed by the very high heat flow. The velocity model shows that this basement to the west of the Brawley Seismic Zone is at ~4-km depth. The basement shallows to ~2-km depth in the active geothermal field and Salton Buttes volcanic field which locally coincide with the Brawley Seismic Zone. At the eastern edge of the geothermal field, the basement drops off again to ~3.5-km depth. The eastern edge of the valley appears to be fault bounded by the along-strike extension of the Sand Hills Fault, an inactive strike-slip fault. The seismic velocities to the east of the fault correspond to metamorphic rock of the Chocolate Mountains, different from the metamorphosed basement in the valley. The western edge of the valley appears to be fault bounded by the active Superstition Hills Fault. To the west of the valley, >4-km deep valley basement extends to the active Superstition Hills Fault. Basement then shallows

Time course field analysis of COMT-downregulated switchgrass: Lignification, recalcitrance, and rust susceptibility

DOE PAGES

Baxter, Holly L.; Mazarei, Mitra; Fu, Chunxiang; ...

2016-05-18

Modifying plant cell walls by manipulating lignin biosynthesis can improve biofuel yields from lignocellulosic crops. For example, transgenic switchgrass lines with downregulated expression of caffeic acid O-methyltransferase, a lignin biosynthetic enzyme, produce up to 38% more ethanol than controls. The aim of the present study was to understand cell wall lignification over the second and third growing seasons of COMT-downregulated field-grown switchgrass. COMT gene expression, lignification, and cell wall recalcitrance were assayed for two independent transgenic lines at monthly intervals. Switchgrass rust (Puccinia emaculata) incidence was also tracked across the seasons. Trends in lignification over time differed between the 2more » years. In 2012, sampling was initiated in mid-growing season on reproductive-stage plants and there was little variation in the lignin content of all lines (COMT-downregulated and control) over time. COMT-downregulated lines maintained 11-16% less lignin, 33-40% lower S/G (syringyl-to-guaiacyl) ratios, and 15-42% higher sugar release relative to controls for all time points. In 2013, sampling was initiated earlier in the season on elongation-stage plants and the lignin content of all lines steadily increased over time, while sugar release expectedly decreased. S/G ratios increased in non-transgenic control plants as biomass accumulated over the season, while remaining relatively stable across the season in the COMT-downregulated lines. Differences in cell wall chemistry between transgenic and non-transgenic lines were not apparent until plants transitioned to reproductive growth in mid-season, after which the cell walls of COMT-downregulated plants exhibited phenotypes consistent with what was observed in 2012. There were no differences in rust damage between transgenics and controls at any time point. Finally, these results provide relevant fundamental insights into the process of lignification in a maturing field-grown biofuel

Time course field analysis of COMT-downregulated switchgrass: Lignification, recalcitrance, and rust susceptibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, Holly L.; Mazarei, Mitra; Fu, Chunxiang

Modifying plant cell walls by manipulating lignin biosynthesis can improve biofuel yields from lignocellulosic crops. For example, transgenic switchgrass lines with downregulated expression of caffeic acid O-methyltransferase, a lignin biosynthetic enzyme, produce up to 38% more ethanol than controls. The aim of the present study was to understand cell wall lignification over the second and third growing seasons of COMT-downregulated field-grown switchgrass. COMT gene expression, lignification, and cell wall recalcitrance were assayed for two independent transgenic lines at monthly intervals. Switchgrass rust (Puccinia emaculata) incidence was also tracked across the seasons. Trends in lignification over time differed between the 2more » years. In 2012, sampling was initiated in mid-growing season on reproductive-stage plants and there was little variation in the lignin content of all lines (COMT-downregulated and control) over time. COMT-downregulated lines maintained 11-16% less lignin, 33-40% lower S/G (syringyl-to-guaiacyl) ratios, and 15-42% higher sugar release relative to controls for all time points. In 2013, sampling was initiated earlier in the season on elongation-stage plants and the lignin content of all lines steadily increased over time, while sugar release expectedly decreased. S/G ratios increased in non-transgenic control plants as biomass accumulated over the season, while remaining relatively stable across the season in the COMT-downregulated lines. Differences in cell wall chemistry between transgenic and non-transgenic lines were not apparent until plants transitioned to reproductive growth in mid-season, after which the cell walls of COMT-downregulated plants exhibited phenotypes consistent with what was observed in 2012. There were no differences in rust damage between transgenics and controls at any time point. Finally, these results provide relevant fundamental insights into the process of lignification in a maturing field-grown biofuel

Structural characterization (1->2)-beta-xylose-(1->3)-alpha-arabinose-containing oligosaccharide products of extracted switchgrass (Panicum virgatum, L.) xylan treatment with alpha-arabinofuranosidase and beta-endo-xylanase.

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum, L.) is a potential dedicated biomass crop for use in biocatalytic conversion systems to biofuels. Nearly 30% of switchgrass cell wall material is xylan. The complete depolymerization of xylan is desirable both as an additional carbon source for microbial fermentation a...

Impact of AFEX™ Pretreatment and Extrusion Pelleting on Pellet Physical Properties and Sugar Recovery from Corn Stover, Prairie Cord Grass, and Switchgrass.

PubMed

Sundaram, Vijay; Muthukumarappan, Kasiviswanathan

2016-05-01

The effects of AFEX™ pretreatment, feedstock moisture content (5,10, and 15 % wb), particle size (screen sizes of 2, 4, and 8 mm), and extrusion temperature (75, 100, and 125 °C) on pellet bulk density, pellet hardness, and sugar recovery from corn stover, prairie cord grass, and switchgrass were investigated. Pellets were produced from untreated and AFEX™ pretreated feedstocks using a laboratory-scale extruder. AFEX™ pretreatment increased subsequent pellet bulk density from 453.0 to 650.6 kg m(-3) for corn stover from 463.2 to 680.1 kg m(-3) for prairie cord grass, and from 433.9 to 627.7 kg m(-3) for switchgrass. Maximum pellet hardness of 2342.8, 2424.3, and 1298.6 N was recorded for AFEX™ pretreated corn stover, prairie cord grass, and switchgrass, respectively. Glucose yields of AFEX™ corn stover pellets, prairie cord grass, and switchgrass pellets varied from 88.9 to 94.9 %, 90.1 to 94.9 %, and 87.0 to 92.9 %, respectively. Glucose and xylose yields of AFEX™ pellets were not affected by the extruder barrel temperature and the hammer mill screen size. The results obtained showed that low temperature and large particle size during the extrusion pelleting process can be employed for AFEX™-treated biomass without compromising sugar yields.

Nitrogen uptake by corn and switchgrass plants in soils of varying depths in Central Missouri

USDA-ARS?s Scientific Manuscript database

Sustainable biomass feedstock production systems involve biomass generation from non-agricultural or marginal lands with minimal external inputs. Switchgrass based alley cropping systems have been proposed as biomass feedstock crop systems in marginal lands. In many areas in the Midwest United State...

Genomic diversity in switchgrass (Panicum virgatum): from the continental scale to a dune landscape

PubMed Central

Morris, Geoffrey P.; Grabowski, Paul; Borevitz, Justin O.

2011-01-01

Connecting broad-scale patterns of genetic variation and population structure to genetic diversity on a landscape is a key step towards understanding historical processes of migration and adaptation. New genomic approaches can be used to increase the resolution of phylogeographic studies while reducing locus sampling effects and circumventing ascertainment bias. Here, we use a novel approach based on high-throughput sequencing to characterize genetic diversity in complete chloroplast genomes and >10,000 nuclear loci in switchgrass, across a continental and landscape scale. Switchgrass is a North American tallgrass species, which is widely used in conservation and perennial biomass production, and shows strong ecotypic adaptation and population structure across the continental range. We sequenced 40.9 billion base pairs from 24 individuals from across the species’ range and 20 individuals from the Indiana Dunes. Analysis of plastome sequence revealed 203 variable SNP sites that define eight haplogroups, which are differentiated by 4 to 127 SNPs and confirmed by patterns of indel variation. These include three deeply divergent haplogroups, which correspond to the previously described lowland-upland ecotypic split and a novel upland haplogroup split that dates to the mid-Pleistoscene. Most of the plastome haplogroup diversity present in the northern switchgrass range, including in the Indiana Dunes, originated in the mid- or upper-Pleistocene prior to the most recent postglacial recolonization. Furthermore, a recently colonized landscape feature (~150 ya) in the Indiana Dunes contains several deeply divergent upland haplogroups. Nuclear markers also support a deep lowland-upland split, followed by limited gene flow, and show extensive gene flow in the local population of the Indiana Dunes. PMID:22060816

The Role of the Goldstone Apple Valley Radio Telescope Project in Promoting Scientific Efficacy among Middle and High School Students.

ERIC Educational Resources Information Center

Ibe, Mary; Deutscher, Rebecca

This study investigated the effects on student scientific efficacy after participation in the Goldstone Apple Valley Radio Telescope (GAVRT) project. In the GAVRT program, students use computers to record extremely faint radio waves collected by the telescope and analyze real data. Scientific efficacy is a type of self-knowledge a person uses to…

Impacts of root traits and genotypic diversity in switchgrass cropping systems on biogeochemical cycling of soil carbon and nitrogen

NASA Astrophysics Data System (ADS)

De Graaff, M. A.; Jastrow, J. D.; Adkins, J.; Johns, A. C.; Morris, G.; Six, J.

2016-12-01

Land-use change for bioenergy production can create greenhouse gas (GHG) emissions through disturbance of soil carbon (C) pools, but native species with extensive root systems may rapidly repay the GHG debt by enhancing soil C sequestration upon land-use change, particularly when grown in diverse mixtures. Here we investigated how root traits and genotypic diversity in switchgrass (Panicum virgatum) impacts yield, nitrogen (N) cycling and soil C stabilization. Owing to extensive within-species variation in root morphology and architecture among the switchgrass cultivars, we hypothesized that increasing cultivar diversity would enhance belowground niche differentiation, thereby increasing N use efficiency, yield, and ultimately soil C stabilization. Our experiment was conducted at the Fermilab National Environmental Research Park, in northeastern Illinois, USA, where we varied the level of switchgrass genotypic diversity using various local and non-local cultivars (1, 2, 4, or 6 cultivars per plot) in a replicated field trial. We found that genotypic mixtures had one-third higher biomass production than the average monoculture, and no monoculture was significantly higher yielding than the average mixture. Further, year-to-year variation in yields was reduced in the mixture of switchgrass relative to the species monocultures. Despite positive impacts of increased intraspecific diversity on biomass production, we found no effect on N use efficiency, or soil C sequestration. However there were differences among cultivars in soil C input and soil C stabilization. These differences were related to specific root length (SRL), where greater SRL was accompanied by more root-derived soil C. Our findings suggest SRL is a root trait that affects soil C input, and that genotypic mixtures could help provide high, stable yields of high-quality biomass feedstocks.

Different Effects of Corn Ethanol and Switchgrass-Based Biofuels on Soil Erosion and Nutrients Loads in the Iowa River Basin

NASA Astrophysics Data System (ADS)

Wu, Y.; Liu, S.

2010-12-01

Biofuels have become important alternative energy resources and their use is likely to expand in the foreseeable future. The expansion of corn-based ethanol production has resulted in a tightening of the global corn supply-and-demand balance. Perennial grasses such as switchgrass (Panicum virgatum) are also being considered as candidates for biofuel feedstocks. Expansion of biofuel production will generate diverse impacts on the economy and environment. How to optimize land use activities to address the need for biofuel production while protecting the environment is still a grand challenge. Unfortunately, little is known about the effects of biofuel-oriented alternative land uses on water quality. Can we produce the same amount or more biofuels by converting some cornfields to switchgrass, for example, while reducing environmental pressure? The objective of this study was to evaluate the potential impacts of land cover change from corn to switchgrass (e.g., on marginal lands) and related management activities on water quality in the Iowa River Basin (drainage area of 32,360 km2) using the Soil and Water Assessment Tool (SWAT). The model was calibrated and validated under baseline conditions using daily streamflow and sediment, and monthly nutrients at Wapello, Iowa (near the outlet of the watershed). The preliminary results show that both the annual average sediment yield and nitrate nitrogen load would decrease when marginal corn areas are converted to switchgrass. However, the magnitude of change depends greatly on the detailed management practices, such as techniques and amount of fertilization, harvesting practices, and residue management.

Geologic history of the Yosemite Valley

USGS Publications Warehouse

Matthes, Francois E.

1930-01-01

Projection of the longitudinal profiles of these hanging valleys forward to the axis of the Merced Canyon shows that they are closely accordant in height. Their profiles indicate a series of points on a former profile of the Merced with respect to which the side streams had graded their courses prior to the last uplift. This old profile can be extended upward into the glaciated part of the Merced Canyon above El Portal and even into the profoundly glaciated Yosemite Valley, accordant points being furnished by a number of hanging side valleys (due allowance being made for glacial erosion suffered by those valleys). However, not all the hanging valleys of the Yosemite region are accordant with this set. Several of them, including the upland valley of Yosemite Creek, constitute a separate set indicating another old profile of the Merced at a level 600 to 1,000 feet higher than the first. Others, including the hanging gulch of lower Bridalveil Creek, point to an old profile of the Merced about 1,200 feet lower than the first. There are thus three distinct sets of hanging valleys produced in three cycles of stream erosion. The valleys of the upper set, like those of the middle set, were left hanging as a result of rapid trenching by the Merced induced by an uplift of the range, there having been two such uplifts. Only the valleys of the lower set hang because of glacial deepening and widening of the Yosemite Valley, the cycle in which they were cut having been interrupted by the advent of the Pleistocene glaciers. They consequently indicate the preglacial depth of the Yosemite Valley. That depth, measured from the brow of El Capitan, was about 2,400 feet; measured from the rim at Glacier Point it was about 2,000 feet.

Responses of switchgrass soil respiration and its components to precipitation gradient in a mescocosm study

USDA-ARS?s Scientific Manuscript database

The objectives of this study were to investigate the effects of the precipitation changes on soil, microbial and root respirations of switchgrass soils, and the relationships between soil respiration and plant growth, soil moisture and temperature. A mesocosm experiment was conducted with five prec...

Evaluation of chopped switchgrass and chopped bermudagrass as litter materials over multiple heavy broiler flocks

USDA-ARS?s Scientific Manuscript database

Chopped switchgrass (SG) and chopped bermudagrass (BG) were evaluated as alternatives to pine shavings (PS) for broiler litter over 3 flocks. Twenty-four pens were filled with the 3 litter types. Live performance parameters included mortality, BW, BW gain, feed consumption, and feed conversion. Mort...

Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

USDA-ARS?s Scientific Manuscript database

The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

Intercropping with switchgrass improves net greenhouse gas balance in hybrid poplar plantations on a sand soil

USDA-ARS?s Scientific Manuscript database

Highly productive, commercial hybrid poplar plantations are being managed in the Pacific Northwest for high-value timber production at relatively low stocking densities under irrigation. The open understory was used to produce switchgrass (Panicum virgatum) prior to canopy closure. The objectives ...

Industrial hemp as a potential bioenergy crop in comparison with kenaf, switchgrass and biomass sorghum.

PubMed

Das, Lalitendu; Liu, Enshi; Saeed, Areej; Williams, David W; Hu, Hongqiang; Li, Chenlin; Ray, Allison E; Shi, Jian

2017-11-01

This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of Weather on the Predicted Moisture Content of Field Chopped EnergySorghum and Switchgrass

DOE PAGES

Popp, Michael P.; Searcy, Stephen S.; Sokhansanj, Shahab; ...

2015-03-25

To determine the effects of weather on harvested moisture content (MC) of switchgrass (Panicum virgatum) and energy sorghum (Sorghum bicolor), tracking of harvest progress on individual fields in the Integrated Biomass Supply and Logistics (IBSAL) model was modified to allow: i) rewetting of swathed material in the drying formulae; and ii) field queuing rules based on equipment availability and weather. Estimated crop yield and initial MC by harvest date, as observed in field trials, along with the modeling of different delays between mowing and harvest allowed estimation of harvested MC, annual tonnage processed and associated processing cost differences by cropmore » and location over 10 years. Extending the hours of annual equipment use had minor implications on cost of production. Energy sorghum proved difficult to dry in the field. Its higher yield, leading to shorter supply distance to the plant, may justify harvesting of energy sorghum early in the season with drier weather. Lastly, later harvest for lower-yielding switchgrass offers MC advantages.« less

Influence of Weather on the Predicted Moisture Content of Field Chopped EnergySorghum and Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popp, Michael P.; Searcy, Stephen S.; Sokhansanj, Shahab

To determine the effects of weather on harvested moisture content (MC) of switchgrass (Panicum virgatum) and energy sorghum (Sorghum bicolor), tracking of harvest progress on individual fields in the Integrated Biomass Supply and Logistics (IBSAL) model was modified to allow: i) rewetting of swathed material in the drying formulae; and ii) field queuing rules based on equipment availability and weather. Estimated crop yield and initial MC by harvest date, as observed in field trials, along with the modeling of different delays between mowing and harvest allowed estimation of harvested MC, annual tonnage processed and associated processing cost differences by cropmore » and location over 10 years. Extending the hours of annual equipment use had minor implications on cost of production. Energy sorghum proved difficult to dry in the field. Its higher yield, leading to shorter supply distance to the plant, may justify harvesting of energy sorghum early in the season with drier weather. Lastly, later harvest for lower-yielding switchgrass offers MC advantages.« less

Groundwater availability of the Central Valley Aquifer, California

USGS Publications Warehouse

Faunt, Claudia C.

2009-01-01

California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

Valley Physics in Non-Hermitian Artificial Acoustic Boron Nitride

NASA Astrophysics Data System (ADS)

Wang, Mudi; Ye, Liping; Christensen, J.; Liu, Zhengyou

2018-06-01

The valley can serve as a new degree of freedom in the manipulation of particles or waves in condensed matter physics, whereas systems containing combinations of gain and loss elements constitute rich building units that can mimic non-Hermitian properties. By introducing gain and loss in artificial acoustic boron nitride, we show that the acoustic valley states and the valley-projected edge states display exotic behaviors in that they sustain either attenuated or amplified wave propagation. Our findings show how non-Hermiticity introduces a mechanism in tuning topological protected valley transports, which may have significance in advanced wave control for sensing and communication applications.

Miscanthus and switchgrass production in central Illinois: impacts on hydrology and inorganic nitrogen leaching.

PubMed

McIsaac, Gregory F; David, Mark B; Mitchell, Corey A

2010-01-01

Biomass crops are being promoted as environmentally favorable alternatives to fossil fuels or ethanol production from maize (Zea mays L.), particularly across the Corn Belt of the United States. However, there are few if any empirical studies on inorganic N leaching losses from perennial grasses that are harvested on an annual basis, nor has there been empirical evaluation of the hydrologic consequences of perennial cropping systems. Here we report on the results of 4 yr of field measurements of soil moisture and inorganic N leaching from a conventional maize-soybean [Glycine max (L.) Merr.] system and two unfertilized perennial grasses harvested in winter for biomass: Miscanthus x giganteus and switchgrass (Panicum virgatum cv. Cave-in-Rock). All crops were grown on fertile Mollisols in east-central Illinois. Inorganic N leaching was measured with ion exchange resin lysimeters placed 50 cm below the soil surface. Maize--soybean nitrate leaching averaged 40.4 kg N ha(-1) yr(-1), whereas switchgrass and Miscanthus had values of 1.4 and 3.0 kg N ha(-1) yr(-1), respectively. Soil moisture monitoring (to a depth of 90 cm) indicated that both perennial grasses dried the soil out earlier in the growing season compared with maize-soybean. Later in the growing season, soil moisture under switchgrass tended to be greater than maize-soybean or Miscanthus, whereas the soil under Miscanthus was consistently drier than under maize--soybean. Water budget calculations indicated that evapotranspiration from Miscanthus was about 104 mm yr(-1) greater than under maize-soybean, which could reduce annual drainage water flows by 32% in central Illinois. Drainage water is a primary source of surface water flows in the region, and the impact ofextensive Miscanthus production on surface water supplies and aquatic ecosystems deserves further investigation.

76 FR 12212 - Notice of Availability of the Finding of No Significant Impact for the Klingle Valley Trail

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-04

... Significant Impact for the Klingle Valley Trail AGENCIES: Federal Highway Administration, District of Columbia...: Notice of availability of the Finding of No Significant Impact for the Klingle Valley Trail Project... availability of the Finding of No Significant Impact (FONSI) for the Klingle Valley Trail Project, pursuant to...

Soil nitrogen dynamics in switchgrass seeded to a marginally yielding cropland of South Dakota

USDA-ARS?s Scientific Manuscript database

Soil nitrate (NO3-), nitrate leaching, and nitrous oxide (N2O) emissions for 2009 through 2015 were monitored to explore N dynamics in switchgrass (Panicum virgatum L.) seeded to a marginally yielding cropland. Our findings indicated that N rate impacted soil NO3- (0-5 cm depth) and soil surface N2O...

Switchgrass biomass composition traits and their effects on its digestion by ruminants and bioconversion to ethanol

USDA-ARS?s Scientific Manuscript database

Six generations of divergent breeding in switchgrass (Panicum virgatum L.) for forage in vitro digestibility (IVDMD) resulted in significant changes in 20 biomass composition traits. Stepwise multi-regression was used to determine which of the 20 composition traits had largest significant effects on...

Water use efficiency by switchgrass compared to a native grass or a native grass alfalfa mixture

USDA-ARS?s Scientific Manuscript database

Development of sustainable cellulosic biofuel systems requires knowing the water use efficiency (WUE) of potential bioenergy crops. Impact of early and late season droughts on WUE and soil water deficits were evaluated in switchgrass (Panicum virgatum L.), western wheatgrass (Pascopyrum smithii (Ry...

Evaluation of intercropped switchgrass establishment under a range of experimental site preparation treatments in a forested setting on the Lower Coastal Plain of North Carolina, U.S.A

Treesearch

Janine M. Albaugh; Eric B. Sucre; Zakiya H. Leggett; Jean-Christophe Domec; John S. King

2012-01-01

There is growing interest in using switchgrass (Panicum virgatum L.) as a biofuel crop and for its potential to sequester carbon. However, there are limited data on the establishment success of this species when grown as a forest intercrop in coastal plain settings of the U.S. Southeast. Therefore, we studied establishment success of switchgrass...

Effect of acid, steam explosion, and size reduction pretreatments on bio-oil production from sweetgum, switchgrass, and corn stover.

PubMed

Wang, Hui; Srinivasan, Radhakrishnan; Yu, Fei; Steele, Philip; Li, Qi; Mitchell, Brian; Samala, Aditya

2012-05-01

Bio-oil produced from biomass by fast pyrolysis has the potential to be a valuable substitute for fossil fuels. In a recent work on pinewood, we found that pretreatment alters the structure and chemical composition of biomass, which influence fast pyrolysis. In this study, we evaluated dilute acid, steam explosion, and size reduction pretreatments on sweetgum, switchgrass, and corn stover feedstocks. Bio-oils were produced from untreated and pretreated feedstocks in an auger reactor at 450 °C. The bio-oil's physical properties of pH, water content, acid value, density, and viscosity were measured. The chemical characteristics of the bio-oils were determined by gas chromatography-mass spectrometry. The results showed that bio-oil yield and composition were influenced by the pretreatment method and feedstock type. Bio-oil yields of 52, 33, and 35 wt% were obtained from medium-sized (0.68-1.532 mm) untreated sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from other sizes. Bio-oil yields of 56, 46, and 51 wt% were obtained from 1% H(2)SO(4)-treated medium-sized sweetgum, switchgrass, and corn stover, respectively, which were higher than the yields from untreated and steam explosion treatments.

The TcEG1 beetle (Tribolium castaneum) cellulase produced in transgenic switchgrass is active at alkaline pH and auto-hydrolyzes biomass for increased cellobiose release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willis, Jonathan D.; Grant, Joshua N.; Mazarei, Mitra

Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes would reduce costs of cellulosic biofuel production. To date, non-bioenergy plant models have been used in nearly all studies assessing the synthesis and activity of plant-produced fungal and bacterial cellulases. One potential source for cellulolytic enzyme genes is herbivorous insects adapted to digest plant cell walls. Here we examine the potential of transgenic switchgrass-produced TcEG1 cellulase from Tribolium castaneum (red flour beetle). This enzyme, when overproduced in Escherichia coli and Saccharomyces cerevisiae, efficiently digests cellulose at optima of 50 °C and pHmore » 12.0. TcEG1 that was produced in green transgenic switchgrass tissue had a range of endoglucanase activity of 0.16–0.05 units (µM glucose release/min/mg) at 50 °C and pH 12.0. TcEG1 activity from air-dried leaves was unchanged from that from green tissue, but when tissue was dried in a desiccant oven (46 °C), specific enzyme activity decreased by 60%. When transgenic biomass was “dropped-in” into an alkaline buffer (pH 12.0) and allowed to incubate at 50 °C, cellobiose release was increased up to 77% over non-transgenic biomass. Saccharification was increased in one transgenic event by 28%, which had a concurrent decrease in lignin content of 9%. Histological analysis revealed an increase in cell wall thickness with no change to cell area or perimeter. Transgenic plants produced more, albeit narrower, tillers with equivalent dry biomass as the control. This work describes the first study in which an insect cellulase has been produced in transgenic plants; in this case, the dedicated bioenergy crop switchgrass. Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic

The TcEG1 beetle (Tribolium castaneum) cellulase produced in transgenic switchgrass is active at alkaline pH and auto-hydrolyzes biomass for increased cellobiose release

DOE PAGES

Willis, Jonathan D.; Grant, Joshua N.; Mazarei, Mitra; ...

2017-11-30

Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes would reduce costs of cellulosic biofuel production. To date, non-bioenergy plant models have been used in nearly all studies assessing the synthesis and activity of plant-produced fungal and bacterial cellulases. One potential source for cellulolytic enzyme genes is herbivorous insects adapted to digest plant cell walls. Here we examine the potential of transgenic switchgrass-produced TcEG1 cellulase from Tribolium castaneum (red flour beetle). This enzyme, when overproduced in Escherichia coli and Saccharomyces cerevisiae, efficiently digests cellulose at optima of 50 °C and pHmore » 12.0. TcEG1 that was produced in green transgenic switchgrass tissue had a range of endoglucanase activity of 0.16–0.05 units (µM glucose release/min/mg) at 50 °C and pH 12.0. TcEG1 activity from air-dried leaves was unchanged from that from green tissue, but when tissue was dried in a desiccant oven (46 °C), specific enzyme activity decreased by 60%. When transgenic biomass was “dropped-in” into an alkaline buffer (pH 12.0) and allowed to incubate at 50 °C, cellobiose release was increased up to 77% over non-transgenic biomass. Saccharification was increased in one transgenic event by 28%, which had a concurrent decrease in lignin content of 9%. Histological analysis revealed an increase in cell wall thickness with no change to cell area or perimeter. Transgenic plants produced more, albeit narrower, tillers with equivalent dry biomass as the control. This work describes the first study in which an insect cellulase has been produced in transgenic plants; in this case, the dedicated bioenergy crop switchgrass. Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic

76 FR 26336 - Notice of Final Federal Agency Actions on the Proposed Klingle Valley Trail in Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-06

... on the Proposed Klingle Valley Trail in Washington, DC AGENCY: Federal Highway Administration (FHWA... final within the meaning of 23 U.S.C. 139(l)(1). The actions relate to the proposed Klingle Valley Trail... approvals for the following project in Northwest Washington, DC: The Klingle Valley Trail project. The...

Economic potential for switchgrass production in the U.S. Northern Plains: A minimum-data analysis

USDA-ARS?s Scientific Manuscript database

There is a demand for timely information to support policy decision making. There is also interest in the potential for alternative crops such as switchgrass to be used for ethanol production and which would have a positive impact on net greenhouse gas emission. This paper uses a new minimum-data mo...

Switchgrass response to nitrogen fertilizer across diverse environments in the USA: a regional feedstock partnership report

USDA-ARS?s Scientific Manuscript database

The Regional Feedstock Partnership is a collaborative effort between the Sun Grant Initiative (through Land Grant Universities), the US Department of Energy, and the US Department of Agriculture. One segment of this partnership is the field-scale evaluation of switchgrass (Panicum virgatum L.) in di...

Fretted Terrain Valley in Coloe Fossae Region

NASA Technical Reports Server (NTRS)

2006-01-01

[figure removed for brevity, see original site] Figure 1 Click on image for larger version

The image in figure 1 shows lineated valley fill in one of a series of enclosed, intersecting troughs known as Coloe (Choloe) Fossae. Lineated valley fill consists of rows of material in valley centers that are parallel to the valley walls. It is probably made of ice-rich material and boulders that are left behind when the ice-rich material sublimates. Very distinct rows can be seen near the south (bottom) wall of the valley. Lineated valley fill is thought to result from mass wasting (downslope movement) of ice-rich material from valley walls towards their centers. It is commonly found in valleys near the crustal dichotomy that separates the two hemispheres of Mars. The valley shown here joins four other valleys with lineated fill near the top left corner of this image. Their juncture is a topographic low, suggesting that the lineated valley fill from the different valleys may be flowing or creeping towards the low area (movement towards the upper left of the image). The valley walls appear smooth at first glance but are seen to be speckled with small craters several meters in diameter at HiRISE resolution (see contrast-enhanced subimage). This indicates that at least some of the wall material has been stable to mass wasting for some period of time. Also seen on the valley wall are elongated features shaped like teardrops. These are most likely slightly older craters that have been degraded due to potentially recent downhill creep. It is unknown whether the valley walls are shedding material today. The subimage is approximately 140 x 400 m (450 x 1280 ft).

Image PSP_001372_2160 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on November 11, 2006. The complete image is centered at 35.5 degrees latitude, 56.8 degrees East longitude. The range to the target site was 290.3 km (181

Asymmetric valley-resolved beam splitting and incident modes in slanted graphene junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsieh, S. H.; Chu, C. S.

2016-01-18

Electron injection into a graphene sheet through a slanted armchair graphene nanoribbon (AGNR) is investigated. An incident mode, or subband, in the AGNR is valley-unpolarized. Our attention is on the valley-resolved nature of the injected electron beams and its connection to the incident mode. It is known for a normal injection that an incident mode will split symmetrically into two valley-resolved beams of equal intensity. We show, in contrast, that slanted injections result in asymmetric valley-resolved beam splitting. The most asymmetric beam splitting cases, when one of the valley-resolved beams has basically disappeared, are found and the condition derived. Thismore » is shown not due to trigonal warping because it holds even in the low incident energy regime, as long as collimation allows. These most asymmetric beam splitting cases occur at energies within an energy interval near and include the subband edge of an incident mode. The physical picture is best illustrated by a projection of the slanted AGNR subband states onto that of the 2D graphene sheet. It follows that the disappearing of a valley-resolved beam coincides with the situation that the group velocities of the projected states in the corresponding valley are in backward directions.« less

Effect of topsoil thickness on soil water infiltration in corn-soybean rotation and switchgrass production systems

USDA-ARS?s Scientific Manuscript database

Switchgrass and corn are sometimes used as a resource for biofuel production. The effect of production management systems on water infiltration is very critical in claypan landscape to increase production as well as minimize economic and environmental risks. The objective of this study was to evalua...

Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

USDA-ARS?s Scientific Manuscript database

This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

Long Valley Coring Project, Inyo County, California, 1998, preliminary stratigraphy and images of recovered core

USGS Publications Warehouse

Sackett, Penelope C.; McConnell, Vicki S.; Roach, Angela L.; Priest, Susan S.; Sass, John H.

1999-01-01

Phase III of the Long Valley Exploratory Well, the Long Valley Coring Project, obtained continuous core between the depths of 7,180 and 9,831 ft (2,188 to 2,996 meters) during the summer of 1998. This report contains a compendium of information designed to facilitate post-drilling research focussed on the study of the core. Included are a preliminary stratigraphic column compiled primarily from field observations and a general description of well lithology for the Phase III drilling interval. Also included are high-resolution digital photographs of every core box (10 feet per box) as well as scanned images of pieces of recovered core. The user can easily move from the stratigraphic column to corresponding core box photographs for any depth. From there, compressed, "unrolled" images of the individual core pieces (core scans) can be accessed. Those interested in higher-resolution core scans can go to archive CD-ROMs stored at a number of locations specified herein. All core is stored at the USGS Core Research Center in Denver, Colorado where it is available to researchers following the protocol described in this report. Preliminary examination of core provided by this report and the archive CD-ROMs should assist researchers in narrowing their choices when requesting core splits.

76 FR 78628 - Copper Valley Electric Association, Inc.; Notice of Application and Applicant-Prepared EA...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-19

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13124-003] Copper Valley... Application: Major License. b. Project No.: P-13124-003. c. Date filed: August 30, 2011. d. Applicant: Copper.... 791 (a)-825(r). h. Applicant Contact: Robert A. Wilkinson, CEO, Copper Valley Electric Association...

Salton Seismic Imaging Project Line 5—the San Andreas Fault and Northern Coachella Valley Structure, Riverside County, California

NASA Astrophysics Data System (ADS)

Rymer, M. J.; Fuis, G.; Catchings, R. D.; Goldman, M.; Tarnowski, J. M.; Hole, J. A.; Stock, J. M.; Matti, J. C.

2012-12-01

The Salton Seismic Imaging Project (SSIP) is a large-scale, active- and passive-source seismic project designed to image the San Andreas Fault (SAF) and the adjacent basins (Imperial and Coachella Valleys) in southern California. Here, we focus on SSIP Line 5, one of four 2-D NE-SW-oriented seismic profiles that were acquired across the Coachella Valley. The 38-km-long SSIP-Line-5 seismic profile extends from the Santa Rosa Ranges to the Little San Bernardino Mountains and crosses both strands of the SAF, the Mission Creek (MCF) and Banning (BF) strands, near Palm Desert. Data for Line 5 were generated from nine buried explosive sources (most spaced about 2 to 8 km apart) and were recorded on approximately 281 Texan seismographs (average spacing 138 m). First-arrival refractions were used to develop a refraction tomographic velocity image of the upper crust along the seismic profile. The seismic data were also stacked and migrated to develop low-fold reflection images of the crust. From the surface to about 8 km depth, P-wave velocities range from about 2 km/s to more than 7.5 km/s, with the lowest velocities within a well-defined (~2-km-deep, 15-km-wide) basin (< 4 km/s), and the highest velocities below the transition from the Coachella Valley to the Santa Rosa Ranges on the southwest and within the Little San Bernardino Mountains on the northeast. The MCF and BF strands of the SAF bound an approximately 2.5-km-wide horst-type structure on the northeastern side of the Coachella Valley, beneath which the upper crust is characterized by a pronounced low-velocity zone that extends to the bottom of the velocity image. Rocks within the low-velocity zone have significantly lower velocities than those to the northeast and the southwest at the same depths. Conversely, the velocities of rocks on both sides of the Coachella Valley are greater than 7 km/s at depths exceeding about 4 km. The relatively narrow zone of shallow high-velocity rocks between the surface traces of

Phytoremediation of biosolids from an end-of-life municipal lagoon using cattail (Typha latifolia L.) and switchgrass (Panicum virgatum L.).

PubMed

Jeke, Nicholson N; Hassan, Adenike O; Zvomuya, Francis

2017-03-04

Land spreading of biosolids as a disposal option is expensive and can disperse pathogens and contaminants in the environment. This growth room study examined phytoremediation using switchgrass (Panicum virgatum L.) and cattail (Typha latifolia L.) as an alternative to land spreading of biosolids. Seedlings were transplanted into pots containing 3.9 kg of biosolids (dry wt.). Aboveground biomass (AGB) was harvested either once or twice during each 90-day growth period. Switchgrass AGB yield was greater with two harvests than with one harvest during the first 90-day growth period, whereas cattail yield was not affected by harvest frequency. In the second growth period, harvesting frequency did not affect the yield of either plant species. However, repeated harvesting significantly improved nitrogen (N) and phosphorus (P) uptake by both plants in the first period. Phytoextraction of P was significantly greater for switchgrass (3.9% of initial biosolids P content) than for cattail (2.8%), while plant species did not have a significant effect on N phytoextraction. The trace element accumulation in the AGB of both plant species was negligible. Phytoextraction rates attained in this study suggest that phytoremediation can effectively remove P from biosolids and offers a potentially viable alternative to the disposal of biosolids on agricultural land.

Survival of Salmonella, Escherichia coli 0157:H7, non-0157 shiga toxin producing E.coli, and potential surrogate bacteria in crop soil as affected by the addition of fast pyrolysis-generated switchgrass biochar

USDA-ARS?s Scientific Manuscript database

Fast pyrolysis of switchgrass (and resultant biochar) can be used for bio-fuel production, soil amendments for fertilizing crops, binding heavy metals, and sequestering environmental biocarbon. To determine the influence of fast pyrolysis-generated switchgrass biochar on survival of foodborne path...

Selection signatures in four lignin genes from switchgrass populations divergently selected for in vitro dry matter digestibility

USDA-ARS?s Scientific Manuscript database

Switchgrass is undergoing development as a dedicated cellulosic bioenergy crop. Fermentation of lignocellulosic biomass to ethanol in a bioenergy system, or to volatile fatty acids in a livestock production system, is strongly and negatively influenced by lignification of cell walls. This study dete...

Greenhouse gas fluxes and root productivity in a switchgrass and loblolly pine intercropping system for bioenergy production

Treesearch

Paliza Shrestha; John R. Seiler; Brian D. Strahm; Eric B. Sucre; Zakiya H. Leggett

2015-01-01

This study is part of a larger collaborative effort to determine the overall environmental sustainability of intercropping pine (Pinus taeda L.) and switchgrass (Panicum virgatum L.), both of which are promising feedstock for bioenergy production in the Lower Coastal Plain in North Carolina.

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

PubMed Central

Milano, Elizabeth R.; Lowry, David B.; Juenger, Thomas E.

2016-01-01

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes. PMID:27613751

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE PAGES

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

2016-09-09

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

Changes in forage quality, ingestive mastication, and digesta kinetics resulting from switchgrass maturity.

PubMed

Burns, J C; Pond, K R; Fisher, D S; Luginbuhl, J M

1997-05-01

Five maturities of switchgrass hay harvested at 14-d intervals (vegetative through 20% heading) were fed to Hereford steers (297 kg) in a 5 x 5 Latin square. Relationships with switchgrass maturity were negative and quadratic (P < .05) for DMI and cubic (P < .05) for digestible DMI. Declines in apparent digestibilities of DM, ADF, and cellulose were cubic (P < .05), whereas these were quadratic (P < .05) for NDF, hemicellulose, and CP. Whole masticates from the least, mid, and most mature hays showed linear (P < .05) declines in DM concentration and IVDMD with increasing maturity, whereas NDF concentrations increased linearly (P < .05). Mean retention time of gastrointestinal DM increased linearly (P < .01) from 64 to 94 h from the least to the most mature hay, and the associated rate of passage declined linearly (P < .01) from 3.3 to 2.1%/h. Sieving of masticate DM showed a reduced proportion of large particles (> or = 2.8 mm) and an increased proportion of small particles (< or = .5 mm) with advancing forage maturity. More than 94% of the sieved fecal DM passed a 1.0-mm sieve, but particle sizes showed the same relationship with forage maturity as noted for masticate DM. This occurred despite the comminution from the rumination and digestive processes.

Global Simulation of Bioenergy Crop Productivity: Analytical Framework and Case Study for Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Shujiang; Kline, Keith L; Nair, S. Surendran

A global energy crop productivity model that provides geospatially explicit quantitative details on biomass potential and factors affecting sustainability would be useful, but does not exist now. This study describes a modeling platform capable of meeting many challenges associated with global-scale agro-ecosystem modeling. We designed an analytical framework for bioenergy crops consisting of six major components: (i) standardized natural resources datasets, (ii) global field-trial data and crop management practices, (iii) simulation units and management scenarios, (iv) model calibration and validation, (v) high-performance computing (HPC) simulation, and (vi) simulation output processing and analysis. The HPC-Environmental Policy Integrated Climate (HPC-EPIC) model simulatedmore » a perennial bioenergy crop, switchgrass (Panicum virgatum L.), estimating feedstock production potentials and effects across the globe. This modeling platform can assess soil C sequestration, net greenhouse gas (GHG) emissions, nonpoint source pollution (e.g., nutrient and pesticide loss), and energy exchange with the atmosphere. It can be expanded to include additional bioenergy crops (e.g., miscanthus, energy cane, and agave) and food crops under different management scenarios. The platform and switchgrass field-trial dataset are available to support global analysis of biomass feedstock production potential and corresponding metrics of sustainability.« less

Defined tetra-allelic gene disruption of the 4-coumarate:coenzyme A ligase 1 (Pv4CL1) gene by CRISPR/Cas9 in switchgrass results in lignin reduction and improved sugar release.

PubMed

Park, Jong-Jin; Yoo, Chang Geun; Flanagan, Amy; Pu, Yunqiao; Debnath, Smriti; Ge, Yaxin; Ragauskas, Arthur J; Wang, Zeng-Yu

2017-01-01

The development of genome editing technologies offers new prospects in improving bioenergy crops like switchgrass ( Panicum virgatum ). Switchgrass is an outcrossing species with an allotetraploid genome (2 n  = 4 x  = 36), a complexity which forms an impediment to generating homozygous knock-out plants. Lignin, a major component of the plant cell wall and a contributor to cellulosic feedstock's recalcitrance to decomposition, stands as a barrier to efficient biofuel production by limiting enzyme access to cell wall polymers during the fermentation process. We developed a CRISPR/Cas9 genome editing system in switchgrass to target a key enzyme involved in the early steps of monolignol biosynthesis, 4-Coumarate:coenzyme A ligase (4CL). Three 4CL genes, Pv4CL1 , Pv4CL2, and Pv4CL3 , were identified in switchgrass. Expression analysis revealed that Pv4CL1 transcripts were more abundant in the stem than in the leaf, while Pv4CL2 transcripts were barely detectable and Pv4CL3 was mainly expressed in the leaf. Pv4CL1 was selected as the target for CRISPR/Cas9 editing because of its preferential expression in highly lignified stem tissues. Specific guide RNA was constructed to target Pv4CL1 . After introducing the construct into switchgrass calli, 39 transgenic plants were regenerated. Using two rounds of PCR screening and sequencing, four plants were confirmed to have tetra-allelic mutations simultaneously. The Pv4CL1 knock-out plants had reduced cell wall thickness, an 8-30% reduction in total lignin content, a 7-11% increase in glucose release, and a 23-32% increase in xylose release. This study established a successful CRISPR/Cas9 system in switchgrass with mutation efficiency reaching 10%. The system allows the precise targeting of the selected Pv4CL1 gene to create switchgrass knock-out mutant plants with decreased lignin content and reduced recalcitrance.

Temporal dynamics of fibrolytic and methanogenic rumen microorganisms during in situ incubation of switchgrass determined by 16S rRNA gene profiling.

PubMed

Piao, Hailan; Lachman, Medora; Malfatti, Stephanie; Sczyrba, Alexander; Knierim, Bernhard; Auer, Manfred; Tringe, Susannah G; Mackie, Roderick I; Yeoman, Carl J; Hess, Matthias

2014-01-01

The rumen microbial ecosystem is known for its biomass-degrading and methane-producing phenotype. Fermentation of recalcitrant plant material, comprised of a multitude of interwoven fibers, necessitates the synergistic activity of diverse microbial taxonomic groups that inhabit the anaerobic rumen ecosystem. Although interspecies hydrogen (H2) transfer, a process during which bacterially generated H2 is transferred to methanogenic Archaea, has obtained significant attention over the last decades, the temporal variation of the different taxa involved in in situ biomass-degradation, H2 transfer and the methanogenesis process remains to be established. Here we investigated the temporal succession of microbial taxa and its effect on fiber composition during rumen incubation using 16S rRNA amplicon sequencing. Switchgrass filled nylon bags were placed in the rumen of a cannulated cow and collected at nine time points for DNA extraction and 16S pyrotag profiling. The microbial community colonizing the air-dried and non-incubated (0 h) switchgrass was dominated by members of the Bacilli (recruiting 63% of the pyrotag reads). During in situ incubation of the switchgrass, two major shifts in the community composition were observed: Bacilli were replaced within 30 min by members belonging to the Bacteroidia and Clostridia, which recruited 34 and 25% of the 16S rRNA reads generated, respectively. A second significant shift was observed after 16 h of rumen incubation, when members of the Spirochaetes and Fibrobacteria classes became more abundant in the fiber-adherent community. During the first 30 min of rumen incubation ~13% of the switchgrass dry matter was degraded, whereas little biomass degradation appeared to have occurred between 30 min and 4 h after the switchgrass was placed in the rumen. Interestingly, methanogenic members of the Euryarchaeota (i.e., Methanobacteria) increased up to 3-fold during this period of reduced biomass-degradation, with peak abundance just

75 FR 76971 - Lower Valley Energy; Notice of Application for Amendment of License and Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 1651-059] Lower Valley Energy; Notice of Application for Amendment of License and Soliciting Comments, Motions To Intervene, and.... Project No: 1651-059. c. Date Filed: November 17, 2010. d. Applicant: Lower Valley Energy, Inc. e. Name of...

Seedling Biomass Partition and Water Use Efficiency of Switchgrass and Milkvetch in Monocultures and Mixtures in Response to Various Water Availabilities

NASA Astrophysics Data System (ADS)

Xu, Bingcheng; Deng, Xiping; Zhang, Suiqi; Shan, Lun

2010-10-01

Seedling biomass and allocation, transpiration water use efficiency (TWUE), and species competition between switchgrass ( Panicum virgatum L.) and milkvetch ( Astragalus adsurgens Pall.) were investigated in a pot-cultivated experiment under different levels of water availability. The experiment was conducted using a simple replacement design in which switchgrass and milkvetch were grown in growth chamber with ten seedlings per pot, in three combinations of the two species (0:10, 5:5 and 10:0). Five water treatments included sufficient water supply (HW), gradual soil drying from HW (DHW), moderate water stress (LW), gradual soil drying from LW (DLW), and re-establishment of LW conditions after 12 days of drying from LW (RLW). Water treatments were applied over a 15-day period. Biomass production and its partitioning, and TWUE were determined at the end of the experiment. Species competitive indices (competitive ratio (CR), aggressivity (A) and relative yield total (RYT)) were calculated from the biomass dry weight data for shoots, roots and total biomass. Water stress significantly reduced seedling biomass production but increased root:shoot ratios in both monocultures and mixtures. In the RLW treatment, only switchgrass monocultures displayed compensatory biomass production and TWUE, while both species demonstrated compensatory growth in the mixture. Switchgrass was the dominant species and much more aggressive than milkvetch in the LW treatment, while in the other four treatments milkvetch was the dominant species as measured by the positive value of aggressivity and higher values of CR. The total biomass RYT values of the two species were higher than 1.0, indicating some degree of resource complimentarity. In the two-species mixture, although the biomass production was lower than that of milkvetch in the monoculture, there was better TWUE, especially under low and fluctuating water availability.

Bioavailability of Carbohydrate Content in Natural and Transgenic Switchgrasses for the Extreme Thermophile Caldicellulosiruptor bescii

PubMed Central

Zurawski, Jeffrey V.; Khatibi, Piyum A.; Akinosho, Hannah O.; Straub, Christopher T.; Compton, Scott H.; Conway, Jonathan M.; Lee, Laura L.; Ragauskas, Arthur J.; Davison, Brian H.; Adams, Michael W. W.

2017-01-01

ABSTRACT Improving access to the carbohydrate content of lignocellulose is key to reducing recalcitrance for microbial deconstruction and conversion to fuels and chemicals. Caldicellulosiruptor bescii completely solubilizes naked microcrystalline cellulose, yet this transformation is impeded within the context of the plant cell wall by a network of lignin and hemicellulose. Here, the bioavailability of carbohydrates to C. bescii at 70°C was examined for reduced lignin transgenic switchgrass lines COMT3(+) and MYB Trans, their corresponding parental lines (cultivar Alamo) COMT3(−) and MYB wild type (WT), and the natural variant cultivar Cave-in-Rock (CR). Transgenic modification improved carbohydrate solubilization by C. bescii to 15% (2.3-fold) for MYB and to 36% (1.5-fold) for COMT, comparable to the levels achieved for the natural variant, CR (36%). Carbohydrate solubilization was nearly doubled after two consecutive microbial fermentations compared to one microbial step, but it never exceeded 50% overall. Hydrothermal treatment (180°C) prior to microbial steps improved solubilization 3.7-fold for the most recalcitrant line (MYB WT) and increased carbohydrate recovery to nearly 50% for the least recalcitrant lines [COMT3(+) and CR]. Alternating microbial and hydrothermal steps (T→M→T→M) further increased bioavailability, achieving carbohydrate solubilization ranging from 50% for MYB WT to above 70% for COMT3(+) and CR. Incomplete carbohydrate solubilization suggests that cellulose in the highly lignified residue was inaccessible; indeed, residue from the T→M→T→M treatment was primarily glucan and inert materials (lignin and ash). While C. bescii could significantly solubilize the transgenic switchgrass lines and natural variant tested here, additional or alternative strategies (physical, chemical, enzymatic, and/or genetic) are needed to eliminate recalcitrance. IMPORTANCE Key to a microbial process for solubilization of plant biomass is the

Investigation of enzyme formulation on pretreated switchgrass.

PubMed

Falls, Matthew; Shi, Jian; Ebrik, Mirvat A; Redmond, Tim; Yang, Bin; Wyman, Charles E; Garlock, Rebecca; Balan, Venkatesh; Dale, Bruce E; Pallapolu, V Ramesh; Lee, Y Y; Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R; Hames, Bonnie; Thomas, Steve; Donohoe, Bryon S; Vinzant, Todd B; Elander, Richard T; Warner, Ryan E; Sierra-Ramirez, Rocio; Holtzapple, Mark T

2011-12-01

This work studied the benefits of adding different enzyme cocktails (cellulase, xylanase, β-glucosidase) to pretreated switchgrass. Pretreatment methods included ammonia fiber expansion (AFEX), dilute-acid (DA), liquid hot water (LHW), lime, lime+ball-milling, soaking in aqueous ammonia (SAA), and sulfur dioxide (SO(2)). The compositions of the pretreated materials were analyzed and showed a strong correlation between initial xylan composition and the benefits of xylanase addition. Adding xylanase dramatically improved xylan yields for SAA (+8.4%) and AFEX (+6.3%), and showed negligible improvement (0-2%) for the pretreatments with low xylan content (dilute-acid, SO(2)). Xylanase addition also improved overall yields with lime+ball-milling and SO(2) achieving the highest overall yields from pretreated biomass (98.3% and 93.2%, respectively). Lime+ball-milling obtained an enzymatic yield of 92.3kg of sugar digested/kg of protein loaded. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative relationships and chromosome evolution in switchgrass (Panicum virgatum) and its genomic model, foxtail millet (Setaria italica)

USDA-ARS?s Scientific Manuscript database

A switchgrass (Panicum virgatum L.) consensus map was developed that combined data from two mapping populations and integrated recombination data from both parents of this largely obligate outcrossing species. The consensus map consisted of 1,321 loci and spanned 2,122 cM. An analysis of the distri...

Production of polyhydroxybutyrate in switchgrass, a value-added co-product in an important lignocellulosic biomass crop.

PubMed

Somleva, Maria N; Snell, Kristi D; Beaulieu, Julie J; Peoples, Oliver P; Garrison, Bradley R; Patterson, Nii A

2008-09-01

Polyhydroxyalkanoate bio-based plastics made from renewable resources can reduce petroleum consumption and decrease plastic waste disposal issues as they are inherently biodegradable in soil, compost and marine environments. In this paper, the successful engineering of the biomass crop switchgrass (Panicum virgatum L.) for the synthesis of polyhydroxybutyrate (PHB) is reported. Polymer production was monitored in more than 400 primary transformants grown under in vitro and glasshouse conditions. Plants containing up to 3.72% dry weight of PHB in leaf tissues and 1.23% dry weight of PHB in whole tillers were obtained. Results from the analysis of the polymer distribution at the cellular and whole plant levels are presented, and target areas for the improvement of PHB production are highlighted. Polymer accumulation was also analysed in the T(1) generation obtained from controlled crosses of transgenic plants. This study presents the first successful expression of a functional multigene pathway in switchgrass, and demonstrates that this high-yielding biomass crop is amenable to the complex metabolic engineering strategies necessary to produce high-value biomaterials with lignocellulose-derived biofuels.

ASSESSING TRANSBOUNDARY INFLUENCES IN THE LOWER RIO GRANDE VALLEY

EPA Science Inventory

The Lower Rio Grande Valley Transboundary Air Pollution Project (TAPP) was a U.S.-Mexico Border XXI Program project to assess transboundary air pollution in and near Brownsville, Texas. The study used a three-site air monitoring network very close to the border to capture the d...

Preliminary Study of the Effect of the Proposed Long Lake Valley Project Operation on the Transport of Larval Suckers in Upper Klamath Lake, Oregon

USGS Publications Warehouse

Wood, Tamara M.

2009-01-01

A hydrodynamic model of Upper Klamath and Agency Lakes, Oregon, was used to explore the effects of the operation of proposed offstream storage at Long Lake Valley on transport of larval suckers through the Upper Klamath and Agency Lakes system during May and June, when larval fish leave spawning sites in the Williamson River and springs along the eastern shoreline and become entrained in lake currents. A range in hydrologic conditions was considered, including historically high and low outflows and inflows, lake elevations, and the operation of pumps between Upper Klamath Lake and storage in Long Lake Valley. Two wind-forcing scenarios were considered: one dominated by moderate prevailing winds and another dominated by a strong reversal of winds from the prevailing direction. On the basis of 24 model simulations that used all combinations of hydrology and wind forcing, as well as With Project and No Action scenarios, it was determined that the biggest effect of project operations on larval transport was the result of alterations in project management of the elevation in Upper Klamath Lake and the outflow at the Link River and A Canal, rather than the result of pumping operations. This was because, during the spring time period of interest, the amount of water pumped between Upper Klamath Lake and Long Lake Valley was generally small. The dominant effect was that an increase in lake elevation would result in more larvae in the Williamson River delta and in Agency Lake, an effect that was enhanced under conditions of wind reversal. A decrease in lake elevation accompanied by an increase in the outflow at the Link River had the opposite effect on larval concentration and residence time.

Status of groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units, 2005-08: California GAMA Priority Basin Project

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study units are located in California's Central Valley and include parts of Butte, Colusa, Glenn, Placer, Sacramento, Shasta, Solano, Sutter, Tehama, Yolo, and Yuba Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The three study units were designated to provide spatially-unbiased assessments of the quality of untreated groundwater in three parts of the Central Valley hydrogeologic province, as well as to provide a statistically consistent basis for comparing water quality regionally and statewide. Samples were collected in 2005 (Southern Sacramento Valley), 2006 (Middle Sacramento Valley), and 2007-08 (Northern Sacramento Valley). The GAMA studies in the Southern, Middle, and Northern Sacramento Valley were designed to provide statistically robust assessments of the quality of untreated groundwater in the primary aquifer systems that are used for drinking-water supply. The assessments are based on water-quality data collected by the USGS from 235 wells in the three study units in 2005-08, and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter, referred to as primary aquifers) assessed in this study are defined by the depth intervals of the wells in the CDPH database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. The status of the current quality of the groundwater resource was assessed by using data from samples analyzed for volatile organic

78 FR 61984 - Copper Valley Electric Association, Inc.; Notice of Application To Amend License and Accepted for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13124-005] Copper Valley...: Amendment to License. b. Project No: 13124-005. c. Date Filed: September 27, 2013. d. Applicant: Copper..., Copper Valley Electric Association, Inc., P.O. Box 45, Mile 187 Glenn Highway, Glennallen, AK 99588, (907...

Bio-remediation of Pb and Cd polluted soils by switchgrass: A case study in India.

PubMed

Arora, Kalpana; Sharma, Satyawati; Monti, Andrea

2016-01-01

In the present study bioremediation potential of a high biomass yielding grass, Panicum virgatum (switchgrass), along with plant associated microbes (AM fungi and Azospirillum), was tested against lead and cadmium in pot trials. A pot trial was set up in order to evaluate bioremediation efficiency of P. virgatum in association with PAMs (Plant Associated Microbes). Growth parameters and bioremediation potential of endomycorrhizal fungi (AMF) and Azospirillum against different concentrations of Pb and Cd were compared. AM fungi and Azospirillum increased the root length, branches, surface area, and root and shoot biomass. The soil pH was found towards neutral with AMF and Azospirillum inoculations. The bioconcentration factor (BCF) for Pb (12 mg kg(-1)) and Cd (10 mg kg(-1)) were found to be 0.25 and 0.23 respectively and translocation index (Ti) was 17.8 and 16.7 respectively (approx 45% higher than control). The lower values of BCF and Ti, even at highest concentration of Pb and Cd, revealed the capability of switchgrass of accumulating high concentration of Pb and Cd in the roots, while preventing the translocation of Pb and Cd to aerial biomass.

Complete genome sequence of switchgrass mosaic virus, a member of a proposed new species in the genus Marafivirus

USDA-ARS?s Scientific Manuscript database

The complete genome sequence of a virus recently detected in switchgrass (Panicum virgatum) was determined and was found to be closely related to Maize rayado fino virus (MRFV), genus Marafivirus, family Tymoviridae. The genomic RNA is 6408 nucleotides long, excluding the poly (A) tail, and encodes...

Advanced seismic imaging of overdeepened alpine valleys

NASA Astrophysics Data System (ADS)

Burschil, Thomas; Buness, Hermann; Tanner, David; Gabriel, Gerald; Krawczyk, Charlotte M.

2017-04-01

Major European alpine valleys and basins are densely populated areas with infrastructure of international importance. To protect the environment by, e.g., geohazard assessment or groundwater estimation, understanding of the geological structure of these valleys is essential. The shape and deposits of a valley can clarify its genesis and allows a prediction of behaviour in future glaciations. The term "overdeepened" refers to valleys and basins, in which pressurized melt-water under the glacier erodes the valley below the fluvial level. Most overdeepened valleys or basins were thus refilled during the ice melt or remain in the form of lakes. The ICDP-project Drilling Overdeepened Alpine Valleys (DOVE) intends to correlate the sedimentary succession from boreholes between valleys in the entire alpine range. Hereby, seismic exploration is essential to predict the most promising well path and drilling site. In a first step, this DFG-funded project investigates the benefit of multi-component techniques for seismic imaging. At two test sites, the Tannwald Basin and the Lienz Basin, the Leibniz Institute for Applied Geophysics acquired P-wave reflection profiles to gain structural and facies information. Built on the P-wave information, several S-wave reflection profiles were acquired in the pure SH-wave domain as well as 6-C reflection profiles using a horizontal S-wave source in inline and crossline excitation and 3-C receivers. Five P-wave sections reveal the structure of the Tannwald Basin, which is a distal branch basin of the Rhine Glacier. Strong reflections mark the base of the basin, which has a maximum depth of 240 metres. Internal structures and facies vary strongly and spatially, but allow a seismic facies characterization. We distinguish lacustrine, glacio-fluvial, and deltaic deposits, which make up the fill of the Tannwald Basin. Elements of the SH-wave and 6-C seismic imaging correlate with major structures in the P-wave image, but vary in detail. Based on

Production of Butanol (a Biofuel) from Agricultural Residues: Part II - Use of Corn Stover and Switchgrass Hydrolysates

USDA-ARS?s Scientific Manuscript database

Acetone butanol ethanol (ABE or AB, or solvent) was produced from hydrolyzed corn stover and switchgrass using Clostridium beijerinckii P260. A control experiment using glucose resulted in the production of 21.06 gL**-1 total ABE. In this experiment, an AB yield and productivity of 0.41 and 0.31 g...

75 FR 28279 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Hyder Valley Solar...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... Valley Solar Energy Project, Maricopa County, AZ AGENCY: Bureau of Land Management, Interior. ACTION... Solar Energy Project by any of the following methods: E-mail: HyderValley_Solar@blm.gov . Mail: Bureau.... Pacific Solar Investments is also considering the use of thermal energy storage. Thermal energy storage...

A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data

NASA Astrophysics Data System (ADS)

Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.

2013-12-01

The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.

Comparison of solid-state and submerged-state fermentation for the bioprocessing of switchgrass to ethanol and acetate by Clostridium phytofermentans.

PubMed

Jain, Abhiney; Morlok, Charles K; Henson, J Michael

2013-01-01

The conversion of sustainable energy crops using microbiological fermentation to biofuels and bioproducts typically uses submerged-state processes. Alternatively, solid-state fermentation processes have several advantages when compared to the typical submerged-state processes. This study compares the use of solid-state versus submerged-state fermentation using the mesophilic anaerobic bacterium Clostridium phytofermentans in the conversion of switchgrass to the end products of ethanol, acetate, and hydrogen. A shift in the ratio of metabolic products towards more acetate and hydrogen production than ethanol production was observed when C. phytofermentans was grown under solid-state conditions as compared to submerged-state conditions. Results indicated that the end product concentrations (in millimolar) obtained using solid-state fermentation were higher than using submerged-state fermentation. In contrast, the total fermentation products (in weight of product per weight of carbohydrates consumed) and switchgrass conversion were higher for submerged-state fermentation. The conversion of xylan was greater than glucan conversion under both fermentation conditions. An initial pH of 7 and moisture content of 80 % resulted in maximum end products formation. Scanning electron microscopy study showed the presence of biofilm formed by C. phytofermentans growing on switchgrass under submerged-state fermentation whereas bacterial cells attached to surface and no apparent biofilm was observed when grown under solid-state fermentation. To our knowledge, this is the first study reporting consolidated bioprocessing of a lignocellulosic substrate by a mesophilic anaerobic bacterium under solid-state fermentation conditions.

The Salton Seismic Imaging Project: Tomographic characterization of a sediment-filled rift valley and adjacent ranges, southern California

NASA Astrophysics Data System (ADS)

Davenport, K.; Hole, J. A.; Stock, J. M.; Fuis, G. S.; Carrick, E.; Tikoff, B.

2011-12-01

The Salton Trough in Southern California represents the northernmost rift of the Gulf of California extensional system. Relative motion between the Pacific and North American plates is accommodated by continental rifting in step-over zones between the San Andreas, Imperial, and Cerro Prieto transform faults. Rapid sedimentation from the Colorado River has isolated the trough from the southern portion of the Gulf of California, progressively filling the subsiding rift basin. Based on data from previous seismic surveys, the pre-existing continent has ruptured completely, and a new ~22 km thick crust has been created entirely by sedimentation overlying rift-related magmatism. The MARGINS, EarthScope, and USGS-funded Salton Seismic Imaging Project (SSIP) was designed to investigate the nature of this new crust, the ongoing process of continental rifting, and associated earthquake hazards. SSIP, acquired in March 2011, comprises 7 lines of onshore seismic refraction / wide-angle reflection data, 2 lines of refraction / reflection data in the Salton Sea, and a line of broadband stations. This presentation focuses on the refraction / wide-angle reflection line across the Imperial Valley, extending ~220 km across California from Otay Mesa, near Tijuana, to the Colorado River. The data from this line includes seventeen 100-160 kg explosive shots and receivers at 100 m spacing across the Imperial Valley to constrain the structure of the Salton Trough rift basin, including the Imperial Fault. Eight larger shots (600-920 kg) at 20-35 km spacing and receivers at 200-500 m spacing extend the line across the Peninsular Ranges and the Chocolate Mountains. These data will contrast the structure of the rift to that of the surrounding crust and provide constraints on whole-crust and uppermost mantle structure. Preliminary work has included tomographic inversion of first-arrival travel times across the Valley, emphasizing a minimum-structure approach to create a velocity model of the

Extracting valley-ridge lines from point-cloud-based 3D fingerprint models.

PubMed

Pang, Xufang; Song, Zhan; Xie, Wuyuan

2013-01-01

3D fingerprinting is an emerging technology with the distinct advantage of touchless operation. More important, 3D fingerprint models contain more biometric information than traditional 2D fingerprint images. However, current approaches to fingerprint feature detection usually must transform the 3D models to a 2D space through unwrapping or other methods, which might introduce distortions. A new approach directly extracts valley-ridge features from point-cloud-based 3D fingerprint models. It first applies the moving least-squares method to fit a local paraboloid surface and represent the local point cloud area. It then computes the local surface's curvatures and curvature tensors to facilitate detection of the potential valley and ridge points. The approach projects those points to the most likely valley-ridge lines, using statistical means such as covariance analysis and cross correlation. To finally extract the valley-ridge lines, it grows the polylines that approximate the projected feature points and removes the perturbations between the sampled points. Experiments with different 3D fingerprint models demonstrate this approach's feasibility and performance.

Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

DOE PAGES

Yao, Lan; Yang, Haitao; Yoo, Chang Geun; ...

2018-02-06

To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH), three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i) ethanol extraction, followed by (ii) dioxane/H2O extraction, and (iii) cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S) and guaiacyl (G) units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acidmore » (pCA) unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H) unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.« less

Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Lan; Yang, Haitao; Yoo, Chang Geun

To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH), three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i) ethanol extraction, followed by (ii) dioxane/H2O extraction, and (iii) cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S) and guaiacyl (G) units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acidmore » (pCA) unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H) unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.« less

7. Photocopy of map of the Agua Fria Valley and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Photocopy of map of the Agua Fria Valley and lands to be irrigated by the Agua Fria Water and Land Company. Photographer Mark Durben, 1987 Source: 'Map of the Agua Fria Valley and the Western Portion of the Salt River Valley Showing the System of Reservoirs and Canals of the Agua Fria Water and Land Company and the Land to be Irrigated Thereby 160,000 Acres of New Land to be Reclaimed in the Maricopa County, Arizona Territory,' (Brochure) Union Photo Engraving Company, c. 1895, Salt River Project Research Archives, Tempe, Arizona. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

The Use of Radar to Improve Rainfall Estimation over the Tennessee and San Joaquin River Valleys

NASA Technical Reports Server (NTRS)

Petersen, Walter A.; Gatlin, Patrick N.; Felix, Mariana; Carey, Lawrence D.

2010-01-01

This slide presentation provides an overview of the collaborative radar rainfall project between the Tennessee Valley Authority (TVA), the Von Braun Center for Science & Innovation (VCSI), NASA MSFC and UAHuntsville. Two systems were used in this project, Advanced Radar for Meteorological & Operational Research (ARMOR) Rainfall Estimation Processing System (AREPS), a demonstration project of real-time radar rainfall using a research radar and NEXRAD Rainfall Estimation Processing System (NREPS). The objectives, methodology, some results and validation, operational experience and lessons learned are reviewed. The presentation. Another project that is using radar to improve rainfall estimations is in California, specifically the San Joaquin River Valley. This is part of a overall project to develop a integrated tool to assist water management within the San Joaquin River Valley. This involves integrating several components: (1) Radar precipitation estimates, (2) Distributed hydro model, (3) Snowfall measurements and Surface temperature / moisture measurements. NREPS was selected to provide precipitation component.

The Pahrump Valley Museum Yucca Mountain History Exhibit - 12389

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voegele, Michael; McCracken, Robert; Herrera, Troy

As part of its management of the Yucca Mountain project, the Department of Energy maintained several information centers to provide public access to information about the status of the Yucca Mountain project. Those information centers contained numerous displays, historical information, and served as the location for the Department's outreach activities. As the Department of Energy dealt with reduced budgets in 2009 following the Obama Administration's intent to terminate the program, it shut down its information centers. Nye County considered it important to maintain a public information center where people would be able to find information about what was happening withmore » the Yucca Mountain project. Initially the Nye County assumed responsibility for the information center in Pahrump; eventually the County made a decision to move that information center into an expansion of the existing Pahrump Valley Museum. Nye County undertook an effort to update the information about the Yucca Mountain project and modernize the displays. A parallel effort to create a source of historical information where people could find out about the Yucca Mountain project was undertaken. To accompany the Yucca Mountain exhibits in the Pahrump Valley Museum, Nye County also sponsored a series of interviews to document, through oral histories, as much information about the Yucca Mountain project as could be found in these interviews. The paper presents an overview of the Yucca Mountain exhibits in the Pahrump Valley Museum, and the accompanying oral histories. An important conclusion that can be drawn from the interviews is that construction of a repository in Nevada should have been conceptualized as but the first step in transforming the economy of central Nevada by turning part of the Nevada National Security Site and adjoining area into a world-class energy production and energy research center. (authors)« less

Water transfer and major environmental provisions of the Central Valley Project Improvement Act: A preliminary economic evaluation

NASA Astrophysics Data System (ADS)

Loomis, John B.

1994-06-01

Increasing block water pricing, water transfer, and wildlife refuge water supply provisions of the Central Valley Project (CVP) Improvement Act are analyzed in terms of likely farmer response and economic efficiency of these provisions. Based on a simplified partial equilibrium analysis, we estimate small, but significant water conservation savings due to pricing reform, the potential for substantial water transfers to non-CVP customers in severe drought years when the water price exceeds 110 per acre foot (1 acre foot equals 1.234 × 103 m3) and positive net benefits for implementation of the wildlife refuge water supply provisions. The high threshold water price is partly a result of requiring farmers to pay full cost on transferred water plus a surcharge of 25 per acre foot if the water is transferred to a non-CVP user. The act also sets an important precedent for water pricing reform, water transfer provisions, and environmental surcharges on water users that may find their way to other Bureau of Reclamation projects.

Effect of alfalfa (medicago sativa) on fermentation profile and nutritive value of switchgrass (panicum virgatum) and bermudagrass (cynodon dactylon) silages

USDA-ARS?s Scientific Manuscript database

An experiment was conducted at the University of Kentucky Spindletop Farm in Lexington, Kentucky between October and November, 2009 to evaluate the effect of different percentages of alfalfa (Medicago sativa) as mixtures in switchgrass (Panicum virgatus) and bermudagrass (Cynodon dactylon) silages. ...

Valley-dependent band structure and valley polarization in periodically modulated graphene

NASA Astrophysics Data System (ADS)

Lu, Wei-Tao

2016-08-01

The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

Impacts of switchgrass intercropping in traditional pine forests on hydrology and water quality in the southeastern United States.

Treesearch

Devendra Amatya; G.M. Chescheir; J.E. Nettles

2016-01-01

Preliminary results indicate that switchgrass (Panicum virgatum L.), grown as a cellulosic biofuel between managed loblolly pine (Pinus taeda L.) beds on the Atlantic Coastal Plain forests has no significant effect on shallow ground water table and stream outflows. Although management operations (e.g. harvesting, shearing between pine rows, raking, and bedding)...

Modelling the effect of buried valleys on groundwater flow: case study in Ventspils vicinity, Latvia

NASA Astrophysics Data System (ADS)

Delina, Aija; Popovs, Konrads; Bikse, Janis; Retike, Inga; Babre, Alise; Kalvane, Gunta

2015-04-01

encourage groundwater recharge from shallower aquifers. Modelling results with and without valleys shows that buried valleys affect piezometric head in narrow zone around valley. Sand and gravel filled buried valleys recharges confined aquifer with relatively "new" water, thus creating high vulnerability zones in the study area. This research is supported by European Regional Development Fund project Nr.2013/0054/2DP/2.1.1.1.0/13/APIA/VIAA/007 and NRP project EVIDENnT project "Groundwater and climate scenarios" subproject "Groundwater Research". References: Virbulis, J., Timuhins, A., Klints, I., Seņņikovs, J., Bethers, U., Popovs, K. 2012. Script based MOSYS system for the generation of a three dimensional geological structure and the calculation of groundwater flow: case study of the Baltic Artesian Basin. In: Highlights of groundwater research in the Baltic Artesian Basin. University of Latvia, Riga, pp. 53-74.

Development of In Vitro Systems for Switchgrass (Panicum virgatum) - Final Report for 1992 to 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conger, B.V.

2003-01-16

Our project began on July 1, 1992, with the objective of developing systems that could be used in biotechnological approaches to switchgrass improvement. Within six months after initiation of the project, we had worked out protocols in which plants could be regenerated from callus cultures through both organogenesis and somatic embryogenesis. Documentation for both modes of regeneration was provided in our progress reports and in publications. One thousand regenerated plants were established in the field during the first year. We found that Alamo (lowland type) was much more amenable to in vitro culture, and plants could be regenerated much moremore » easily than from Cave-in-Rock (upland type). During the first three years of the project, we studied the influence of genotype, culture medium components, explant type, etc., on regeneration. As mentioned, we found that the lowland cultivars Alamo and Kanlow were much easier to regenerate than upland cultivars, such as Trailblazer, Blackwell, and Cave-in-Rock. For callus induction, we initially used mature caryopses, young leaf tissue, and portions of seedlings. We were successful in inducing callus and regenerating plants from all explants. Two other systems developed during the 4th to 6th year period of the project included multiple shoot formation initiated from germinated seedlings and regenerable suspension cultures. The latter were initiated from embryogenic calluses produced from in vitro developed inflorescences. An important factor for producing multiple shoots was the presence of thidiazuron in the medium. The shoots could be easily rooted and numerous plantlets produced. The last 3 to 4 years of the project focused on anther and microspore culture experiments to produce haploid plants and on genetic transformation. Although thousands of putative haploid plants were produced from a few anthers, they were very weak and difficult to keep alive. Chromosome counts revealed the gametic number in cells where it

76 FR 58293 - Rate Adjustments for Indian Irrigation Projects

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

... 1st Avenue, Parker, AZ 85344, Telephone: (928) 669-7111. Duck Valley Irrigation Project.... Joseph...-feet. Duck Valley Irrigation Project. Basic per acre.... 5.30 5.30 Fort Yuma Irrigation Project Basic...)). Information Quality Act In developing this notice, we did not conduct or use a study, experiment, or survey...

Environmental change and Rift Valley fever in eastern Africa: projecting beyond HEALTHY FUTURES.

PubMed

Taylor, David; Hagenlocher, Michael; Jones, Anne E; Kienberger, Stefan; Leedale, Joseph; Morse, Andrew P

2016-03-31

Outbreaks of Rift Valley fever (RVF), a relatively recently emerged zoonosis endemic to large parts of sub-Saharan Africa that has the potential to spread beyond the continent, have profound health and socio-economic impacts, particularly in communities where resilience is already low. Here output from a new, dynamic disease model [the Liverpool RVF (LRVF) model], driven by downscaled, bias-corrected climate change data from an ensemble of global circulation models from the Inter-Sectoral Impact Model Intercomparison Project run according to two radiative forcing scenarios [representative concentration pathway (RCP)4.5 and RCP8.5], is combined with results of a spatial assessment of social vulnerability to the disease in eastern Africa. The combined approach allowed for analyses of spatial and temporal variations in the risk of RVF to the end of the current century. Results for both scenarios highlight the high-risk of future RVF outbreaks, including in parts of eastern Africa to date unaffected by the disease. The results also highlight the risk of spread from/to countries adjacent to the study area, and possibly farther afield, and the value of considering the geography of future projections of disease risk. Based on the results, there is a clear need to remain vigilant and to invest not only in surveillance and early warning systems, but also in addressing the socio-economic factors that underpin social vulnerability in order to mitigate, effectively, future impacts.

A West Valley Demonstration Project Milestone - Achieving Certification to Ship Waste to the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, J. P.; Pastor, R. S.

2002-02-28

The West Valley Demonstration Project (WVDP) has successfully pretreated and vitrified nearly all of the 600,000 gallons of liquid high-level radioactive waste that was generated at the site of the only commercial nuclear fuel reprocessing plant to have operated in the United States. Low-level waste (LLW) generated during the course of the cleanup effort now requires disposal. Currently the WVDP only ships Class A LLW for off-site disposal. It has been shipping Class A wastes to Envirocare of Utah, Inc. since 1997. However, the WVDP may also have a future need to ship Class B and Class C waste, whichmore » Envirocare is not currently authorized to accept. The Nevada Test Site (NTS), a U.S. Department of Energy (DOE) facility, can accept all three waste classifications. The WVDP set a goal to receive certification to begin shipping Class A wastes to NTS by 2001. Formal certification/approval was granted by the DOE Nevada Operations Office on July 12, 2001. This paper discusses how the WVDP contractor, West Valley Nuclear Services Company (WVNSCO), completed the activities required to achieve NTS certification in 2001 to ship waste to its facility. The information and lessons learned provided are significant because the WVDP is the only new generator receiving certification based on an NTS audit in January 2001 that resulted in no findings and only two observations--a rating that is unparalleled in the DOE Complex.« less

Sun Valley Elementary School Reading and Writing Assessment Project: Final Report.

ERIC Educational Resources Information Center

Zakaluk, Beverley L.

A study investigated the effectiveness of integrating computer technology (multimedia learning resources in a "virtual" classroom) with content area and reading and writing curriculum. All students in grades 2 through 5 at Sun Valley Elementary School, Canada, had their reading and writing assessed. In addition, the writing performance…

Inhibition of microbial biofuel production in drought-stressed switchgrass hydrolysate

DOE PAGES

Ong, Rebecca Garlock; Higbee, Alan; Bottoms, Scott; ...

2016-11-08

Here, interannual variability in precipitation, particularly drought, can affect lignocellulosic crop biomass yields and composition, and is expected to increase biofuel yield variability. However, the effect of precipitation on downstream fermentation processes has never been directly characterized. In order to investigate the impact of interannual climate variability on biofuel production, corn stover and switchgrass were collected during 3 years with significantly different precipitation profiles, representing a major drought year (2012) and 2 years with average precipitation for the entire season (2010 and 2013). All feedstocks were AFEX (ammonia fiber expansion)-pretreated, enzymatically hydrolyzed, and the hydrolysates separately fermented using xylose-utilizing strainsmore » of Saccharomyces cerevisiae and Zymomonas mobilis. As a result, a chemical genomics approach was also used to evaluate the growth of yeast mutants in the hydrolysates.« less

Phosphoric acid based pretreatment of switchgrass and fermentation of entire slurry to ethanol using a simplified process.

PubMed

Wu, Wei; Rondon, Vanessa; Weeks, Kalvin; Pullammanappallil, Pratap; Ingram, Lonnie O; Shanmugam, K T

2018-03-01

Switchgrass (Alamo) was pretreated with phosphoric acid (0.75 and 1%, w/w) at three temperatures (160, 175 and 190 °C) and time (5, 7.5 and 10 min) using a steam gun. The slurry after pretreatment was liquefied by enzymes and the released sugars were fermented in a simultaneous saccharification and co-fermentation process to ethanol using ethanologenic Escherichia coli strain SL100. Among the three variables in pretreatment, temperature and time were critical in supporting ethanol titer and yield. Enzyme hydrolysis significantly increased the concentration of furans in slurries, apparently due to release of furans bound to the solids. The highest ethanol titer of 21.2 ± 0.3 g/L ethanol obtained at the pretreatment condition of 190-1-7.5 (temperature-acid concentration-time) and 10% solids loading accounted for 190 ± 2.9 g ethanol/kg of raw switch grass. This converts to 61.7 gallons of ethanol per ton of dry switchgrass, a value that is comparable to other published pretreatment conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Valley Fill Design and Construction Alternatives to Improve Ecological Performance

EPA Pesticide Factsheets

This presentation discusses; current challenges, comprehensive approaches, BMPs, the Middlefork Development, the Guy Cove project, and a path forward when looking at construction alternatives to improve the ecological performance of valley fills.

Dynamic changes in transcriptome and cell wall composition underlying brassinosteroid-mediated lignification of switchgrass suspension cells.

PubMed

Rao, Xiaolan; Shen, Hui; Pattathil, Sivakumar; Hahn, Michael G; Gelineo-Albersheim, Ivana; Mohnen, Debra; Pu, Yunqiao; Ragauskas, Arthur J; Chen, Xin; Chen, Fang; Dixon, Richard A

2017-01-01

Plant cell walls contribute the majority of plant biomass that can be used to produce transportation fuels. However, the complexity and variability in composition and structure of cell walls, particularly the presence of lignin, negatively impacts their deconstruction for bioenergy. Metabolic and genetic changes associated with secondary wall development in the biofuel crop switchgrass ( Panicum virgatum ) have yet to be reported. Our previous studies have established a cell suspension system for switchgrass, in which cell wall lignification can be induced by application of brassinolide (BL). We have now collected cell wall composition and microarray-based transcriptome profiles for BL-induced and non-induced suspension cultures to provide an overview of the dynamic changes in transcriptional reprogramming during BL-induced cell wall modification. From this analysis, we have identified changes in candidate genes involved in cell wall precursor synthesis, cellulose, hemicellulose, and pectin formation and ester-linkage generation. We have also identified a large number of transcription factors with expression correlated with lignin biosynthesis genes, among which are candidates for control of syringyl (S) lignin accumulation. Together, this work provides an overview of the dynamic compositional changes during brassinosteroid-induced cell wall remodeling, and identifies candidate genes for future plant genetic engineering to overcome cell wall recalcitrance.

Host Genotype and Harvest Practices Shape the Leaf and Root Microbiomes of the Biofuel Crop Switchgrass

NASA Astrophysics Data System (ADS)

Singer, E.; Gonzalez, J.; Juenger, T. E.; Woyke, T.

2016-12-01

Growing energy demands and concerns for climate change have urgently pushed forward the timeline for the implementation of biofuel energies. Switchgrass (Panicum virgatum) is a leading biofuel crop in the United States. Bacteria living on and inside leaves and roots affect plant health, hence a plant's genetic control over its microbiota is of great interest to crop breeders and evolutionary biologists. We present a large-scale field experiment to untangle the effects of genotype, environment, soil horizon and harvest treatment practices on prokaryotic and fungal communities associated with leaves and roots of switchgrass. Using V4 16S rRNA and ITS gene as well as metagenome sequencing, we show that host genotype is significant in both, leaves and roots, and varies among sites. Microbiome composition along the rhizosphere also shifts with soil depth. Furthermore, plant harvest significantly changes both, leaf surface and rhizosphere communities, which can be seen a year after the harvest event. Gene function analysis shows that rhizosphere communities are enriched in genes encoding nitrate reduction, carbohydrate transport and metabolism, motility, and sensory and signal transduction proteins relative to leaf surface communities. Our results demonstrate how genotype-environment interactions contribute to the complexity of microbiome assembly in natural environments.

Evaluation of biogas production potential by dry anaerobic digestion of switchgrass--animal manure mixtures.

PubMed

Ahn, H K; Smith, M C; Kondrad, S L; White, J W

2010-02-01

Anaerobic digestion is a biological method used to convert organic wastes into a stable product for land application with reduced environmental impacts. The biogas produced can be used as an alternative renewable energy source. Dry anaerobic digestion [>15% total solid (TS)] has an advantage over wet digestion (<10% TS) because it allows for the use of a smaller volume of reactor and because it reduces wastewater production. In addition, it produces a fertilizer that is easier to transport. Performance of anaerobic digestion of animal manure-switchgrass mixture was evaluated under dry (15% TS) and thermophilic conditions (55 degrees C). Three different mixtures of animal manure (swine, poultry, and dairy) and switchgrass were digested using batch-operated 1-L reactors. The swine manure test units showed 52.9% volatile solids (VS) removal during the 62-day trial, while dairy and poultry manure test units showed 9.3% and 20.2%, respectively. Over the 62 day digestion, the swine manure test units yielded the highest amount of methane 0.337 L CH4/g VS, while the dairy and poultry manure test units showed very poor methane yield 0.028 L CH4/g VS and 0.002 L CH4/g VS, respectively. Although dairy and poultry manure performed poorly, they may still have high potential as biomass for dry anaerobic digestion if appropriate designs are developed to prevent significant volatile fatty acid (VFA) accumulation and pH drop.

Induced Phytoextraction of Lead Through Chemical Manipulation of Switchgrass and Corn; Role of Iron Supplement.

PubMed

Johnson, Deayne M; Deocampo, Daniel M; El-Mayas, Hanan; Greipsson, Sigurdur

2015-01-01

The effects of combined chemical application of benomyl, ethylenedianinetetraacetate (EDTA), and iron (Fe) (foliar and root) on lead (Pb) phytoextraction by switchgrass (Panicum virgatum) and corn (Zea mays) was examined. Switchgrass was grown in Pb-contaminated urban topsoil with the following treatments: (C) Control, (B) benomyl, (E) EDTA, (F) foliar-Fe, (BE) benomyl + EDTA, (BF) benomyl + foliar-Fe, (FE) foliar-Fe + EDTA, (BFE) benomyl + foliar-Fe + EDTA. Corn was grown in sand-culture supplemented with Pb (500 mg kg(-1)) with the following treatments: (C) control, (B) benomyl, (E) EDTA, (F) root-Fe, (BE) benomyl + EDTA, (BF) benomyl + root-Fe, (FE) root-iron + EDTA, and, (BFE) benomyl + root-Fe + EDTA. All treatments were replicated three times and pots were arranged in a completely randomized design. Plants were analyzed for element concentration (Fe, Zn, P, and Pb) using either inductively coupled plasma (argon) atomic emission spectroscopy (ICP-AES) or graphite furnace atomic absorption spectrometer. Iron supplementation (foliar and root) affected Pb-translocation in plants. Foliar-Fe treatment increased translocation ratio of Pb (TF-Pb) significantly compared to other treatments with the exception of plants treated with benomyl and BF. Root-Fe treatment in combination with EDTA (FE) increased TF-Pb significantly compared to other treatments. Phytoextraction was improved by the combined chemical application; plants treated with BFE treatment increased Pb-total-phytoextraction by 424% compared to Control plants.

Gravity Data from Newark Valley, White Pine County, Nevada

USGS Publications Warehouse

Mankinen, Edward A.; McKee, Edwin H.

2007-01-01

The Newark Valley area, eastern Nevada is one of thirteen major ground-water basins investigated by the BARCAS (Basin and Range Carbonate Aquifer Study) Project. Gravity data are being used to help characterize the geophysical framework of the region. Although gravity coverage was extensive over parts of the BARCAS study area, data were sparse for a number of the valleys, including the northern part of Newark Valley. We addressed this lack of data by establishing seventy new gravity stations in and around Newark Valley. All available gravity data were then evaluated to determine their reliability, prior to calculating an isostatic residual gravity map to be used for subsequent analyses. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a view of subsurface shape of the basin and will provide information useful for the development of hydrogeologic models for the region.

Evapotranspiration of a pine-switchgrass intercropping bioenergy system measured by combined surface renewal and energy balance method

NASA Astrophysics Data System (ADS)

Fischer, M.; Noormets, A.; Domec, J. C.; Rosa, R.; Williamson, J.; Boone, J.; Sucre, E.; Trnka, M.; King, J.

2015-12-01

Intercropping bioenergy grasses within traditional pine silvicultural systems provides an opportunity for economic diversification and regional bioenergy production in a way that complements existing land use systems. Bioenergy intercropping in pine plantations does not compete with food production for land and it is thought will increase ecosystem resource-use efficiencies. As the frequency and intensity of drought is expected to increase with the changing climate, maximizing water use-efficiency of intercropped bioenergy systems will become increasingly important for long-term economic and environmental sustainability. The presented study is focused on evapotranspiration (ET) of an experimental pine-switchgrass intercropping system in the Lower Coastal Plain of North Carolina. We measured ET of two pure switchgrass fields, two pure pine stands and two pine-switchgrass intercropping systems using combined surface renewal (SR) and energy balance (EB) method throughout 2015. SR is based on high-frequency measurement of air temperature at or above canopy. As previously demonstrated, temperature time series are associated with identifiable, repeated patterns called "turbulent coherent structures". These coherent structures are considered to be responsible for most of the turbulent transport. Statistical analysis of the coherent structures in temperature time series allows quantification of sensible heat flux density (H) from the investigated area. Information about H can be combined with measurement of net radiation and soil heat flux density to indirectly obtain ET estimates as a residual of the energy balance equation. Despite the recent progress in the SR method, there is no standard methodology and each method available includes assumptions which require more research. To validate our SR estimates of ET, we used an eddy covariance (EC) system placed temporarily next to the each SR station as a comparative measurement of H. The conference contribution will include

Valley-selective photon-dressed states in transition metal dichalcogenides

NASA Astrophysics Data System (ADS)

LaMountain, Trevor; Chen, Yen-Jung; Stanev, Teodor K.; Stern, Nathaniel P.

2018-02-01

When electronic excitations in a semiconductor interact with light, the relevant quasiparticles are hybrid lightmatter dressed states, or exciton-polaritons. In monolayer transition metal dichalcogenides, a class of 2D direct bandgap semiconductors, optical excitations selectively populate distinct momentum valleys with correlated spin projection. The combination of this spin-valley locking with photon dressed states can lead to new optical phenomena in these materials. We present spectroscopic measurements of valley-specific exciton-polaritons in monolayer 2D materials in distinct regimes. When a monolayer is embedded in a dielectric microcavity, strong coupling exciton-polaritons are achieved. Cavity-modified dynamics of the dressed states are inferred from emission. Polarization persists up to room temperature in monolayer MoS2, in contrast with bare material. We also show that distinct regimes of valley-polarized exciton-polaritons can be accessed with microcavity engineering by tuning system parameters such as cavity decay rate and exciton-photon coupling strength. Further, we report results showing that polarization-sensitive ultrafast spectroscopy can enable sensitive measurements of the valley optical Stark shift, a light-induced dressed state energy shift, in monolayer semiconductors such as WSe2 and MoS2. These findings demonstrate distinct approaches to manipulating the picosecond dynamics of valleysensitive dressed states in monolayer semiconductors.

Water in the Humboldt River Valley near Winnemucca, Nevada

USGS Publications Warehouse

Cohen, Philip M.

1966-01-01

Most of the work of the interagency Humboldt River Research Project in the Winnemucca reach of the Humboldt River valley has been completed. More than a dozen State and Federal agencies and several private organizations and individuals participated in the study. The major objective of the project, which began in 1959, is to evaluate the water resources of the entire Humboldt River basin. However, because of the large size of the basin, most of the work during the first 5 years of the project was done in the Winnemucca area. The purpose of this report is to summarize briefly and simply the information regarding the water resources of the Winnemucca area-especially the quantitative aspects of the flow system-given in previous reports of the project. The Winnemucca reach of the Humboldt River valley, which is in north-central Nevada, is about 200 miles downstream from the headwaters of the Humboldt River and includes that part of the valley between the Comus and Rose Creek gaging stations. Average annual inflow to the storage area (the valley lowlands) in the Winnemucca reach in water years 1949-62 was about 250,000 acre-feet. Of this amount, about 68 percent was Humboldt River streamflow, as measured at the Comus gaging station, 23 percent was precipitation directly on the storage area, 6 percent was ground-water inflow, and about 3 percent was tributary streamflow. Average annual streamflow at the Rose Creek gaging station during the same period was about 155,000 acre-feet, or about 17,000 acre-feet less than that at the Comus gaging station. Nearly all the streamflow lost was consumed by evapotranspiration in the project area. Total average annual evapotranspiration loss during the period was about 115,000 acre-feet, or about 42 percent of the total average annual outflow. The most abundant ions in the ground and surface water in the area are commonly sodium and bicarbonate. Much of the water has a dissolved-solids content that ranges from 500 to 750 parts per

Groundwater quality in Coachella Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to

77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National Park, Inyo... an Environmental Impact Statement for the Saline Valley Warm Springs Management Plan, Death Valley... analysis process for the Saline Valley Warm Springs Management Plan for Death Valley [[Page 33238...

Volume of Valley Networks on Mars and Its Hydrologic Implications

NASA Astrophysics Data System (ADS)

Luo, W.; Cang, X.; Howard, A. D.; Heo, J.

2015-12-01

Valley networks on Mars are river-like features that offer the best evidence for water activities in its geologic past. Previous studies have extracted valley network lines automatically from digital elevation model (DEM) data and manually from remotely sensed images. The volume of material removed by valley networks is an important parameter that could help us infer the amount of water needed to carve the valleys. A progressive black top hat (PBTH) transformation algorithm has been adapted from image processing to extract valley volume and successfully applied to simulated landform and Ma'adim Valles, Mars. However, the volume of valley network excavation on Mars has not been estimated on a global scale. In this study, the PBTH method was applied to the whole Mars to estimate this important parameter. The process was automated with Python in ArcGIS. Polygons delineating the valley associated depressions were generated by using a multi-flow direction growth method, which started with selected high point seeds on a depth grid (essentially an inverted valley) created by PBTH transformation and grew outward following multi-flow direction on the depth grid. Two published versions of valley network lines were integrated to automatically select depression polygons that represent the valleys. Some crater depressions that are connected with valleys and thus selected in the previous step were removed by using information from a crater database. Because of large distortion associated with global dataset in projected maps, the volume of each cell within a valley was calculated using the depth of the cell multiplied by the spherical area of the cell. The volumes of all the valley cells were then summed to produce the estimate of global valley excavation volume. Our initial result of this estimate was ~2.4×1014 m3. Assuming a sediment density of 2900 kg/m3, a porosity of 0.35, and a sediment load of 1.5 kg/m3, the global volume of water needed to carve the valleys was

Fy00 Treasure Valley ITS Deployment Project : advanced traffic management system (ATMS) software procurement and implementation process

DOT National Transportation Integrated Search

2006-08-02

In 2000, the Treasure Valley area of the State of Idaho received a federal earmark of $390,000 to develop an Advanced Transportation Management System (ATMS) for the Treasure Valley region of Idaho. The Ada County Highway District (ACHD), located in ...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

27 CFR 9.57 - Green Valley of Russian River Valley.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River...

DEVELOPMENT OF A POPULATION BALANCE MODEL TO SIMULATE FRACTIONATION OF GROUND SWITCHGRASS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naimi, L.J.; Bi, X.T.; Lau, A.K.

The population balance model represents a time-dependent formulation of mass conservation for a ground biomass that flows through a set of sieves. The model is suitable for predicting the change in size and distribution of ground biomass while taking into account the flow rate processes of particles through a grinder. This article describes the development and application of this model to a switchgrass grinding operation. The mass conservation formulation of the model contains two parameters: breakage rate and breakage ratio. A laboratory knife mill was modified to act as a batch or flow-through grinder. The ground switchgrass was analyzed overmore » a set of six Tyler sieves with apertures ranging from 5.66 mm (top sieve) to 1 mm (bottom sieve). The breakage rate was estimated from the sieving tests. For estimating the breakage ratio, each of the six fractions was further ground and sieved to 11 fractions on a set of sieves with apertures ranging from 5.66 to 0.25 mm (and pan). These data formed a matrix of values for determining the breakage ratio. Using the two estimated parameters, the transient population balance model was solved numerically. Results indicated that the population balance model generally underpredicted the fractions remaining on sieves with 5.66, 4.00, and 2.83 mm apertures and overpredicted fractions remaining on sieves with 2.00, 1.41, and 1.00 mm apertures. These trends were similar for both the batch and flow-through grinder configurations. The root mean square of residuals (RSE), representing the difference between experimental and simulated mass of fractions, was 0.32 g for batch grinding and 0.1 g for flow-through grinding. The breakage rate exhibited a linear function of the logarithm of particle size, with a regression coefficient of 0.99.« less

A project of reuse of reclaimed wastewater in the Po Valley, Italy: Polishing sequence and cost benefit analysis

NASA Astrophysics Data System (ADS)

Verlicchi, P.; Al Aukidy, M.; Galletti, A.; Zambello, E.; Zanni, G.; Masotti, L.

2012-04-01

SummaryThe paper presents a study carried out in the environmentally sensitive area of the Po Valley in northern Italy, with the aim of evaluating, from technical and economic perspectives, a project to reuse part of the final effluent from the Ferrara wastewater treatment plant for irrigation and to develop the site for recreational purposes. Although this area features plentiful supplies of surface water, the Ministry of the Environment has declared it to be at risk of environmental crises due to eutrophication and the drought recurring over the last decade. Thus the availability of fresh water, particularly for agricultural purposes, is threatened, and prompt water saving and protection measures are required. Hence, the possibility of reusing reclaimed wastewater from this plant was investigated, with the aim of exploiting the space around the WWTP, situated within a large urban park, to install natural polishing treatment systems and create green spaces for recreational use. Based on experimental investigation on a pilot plant (featuring both natural and conventional treatments), the study outlines the rationale behind the treatment train selected for the project, details the initial and ongoing costs involved, evaluates the benefits deriving from the project, and assesses public acceptance of the project by the contingent valuation method. A cost-benefit analysis completes the study, and various economic indicators (net present value, benefit-cost ratio, pay-back period, and internal rate of return) revealed that the proposed project was financially feasible.

Defined tetra-allelic gene disruption of the 4-coumarate:coenzyme A ligase 1 (Pv4CL1) gene by CRISPR/Cas9 in switchgrass results in lignin reduction and improved sugar release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jong -Jin; Yoo, Chang Geun; Flanagan, Amy

The development of genome editing technologies offers new prospects in improving bioenergy crops like switchgrass (Panicum virgatum). Switchgrass is an outcrossing species with an allotetraploid genome (2n = 4x = 36), a complexity which forms an impediment to generating homozygous knock-out plants. Lignin, a major component of the plant cell wall and a contributor to cellulosic feedstock’s recalcitrance to decomposition, stands as a barrier to efficient biofuel production by limiting enzyme access to cell wall polymers during the fermentation process.

Defined tetra-allelic gene disruption of the 4-coumarate:coenzyme A ligase 1 (Pv4CL1) gene by CRISPR/Cas9 in switchgrass results in lignin reduction and improved sugar release

DOE PAGES

Park, Jong -Jin; Yoo, Chang Geun; Flanagan, Amy; ...

2017-11-30

The development of genome editing technologies offers new prospects in improving bioenergy crops like switchgrass (Panicum virgatum). Switchgrass is an outcrossing species with an allotetraploid genome (2n = 4x = 36), a complexity which forms an impediment to generating homozygous knock-out plants. Lignin, a major component of the plant cell wall and a contributor to cellulosic feedstock’s recalcitrance to decomposition, stands as a barrier to efficient biofuel production by limiting enzyme access to cell wall polymers during the fermentation process.

Data for ground-water test hole near Zamora, Central Valley Aquifer Project, California

USGS Publications Warehouse

French, J.J.; Page, R.W.; Bertoldi, G.L.

1982-01-01

Preliminary data are presented for the first of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 SE 1/4 sec. 34, T. 12 N. , R. 1 E., Yolo County, California, about 3 miles northeast of the town of Zamora. Drilled to a depth of 2,500 feet below land surface, the hole is cased to a depth of 190 feet and equipped with three piezometer tubes to depths of 947, 1,401, and 2,125 feet. A 5-foot well screen is at the bottom of each piezometer. Eighteen cores and 68 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, diatom identification, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

NASA Technical Reports Server (NTRS)

Kochel, R. Craig; Piper, Jonathan F.

1986-01-01

Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

Diversity and population structure of northern switchgrass as revealed through exome capture sequencing

DOE PAGES

Evans, Joseph; Crisovan, Emily; Barry, Kerrie; ...

2015-10-01

Panicum virgatum L. (switchgrass) is a polyploid, perennial grass species that is native to North America, and is being developed as a future biofuel feedstock crop. Switchgrass is present primarily in two ecotypes: a northern upland ecotype, composed of tetraploid and octoploid accessions, and a southern lowland ecotype, composed of primarily tetraploid accessions. We employed high-coverage exome capture sequencing (~2.4 Tb) to genotype 537 individuals from 45 upland and 21 lowland populations. From these data, we identified ~27 million single-nucleotide polymorphisms (SNPs), of which 1 590 653 high-confidence SNPs were used in downstream analyses of diversity within and between themore » populations. From the 66 populations, we identified five primary population groups within the upland and lowland ecotypes, a result that was further supported through genetic distance analysis. We identified conserved, ecotype-restricted, non-synonymous SNPs that are predicted to affect the protein function of CONSTANS (CO) and EARLY HEADING DATE 1 (EHD1), key genes involved in flowering, which may contribute to the phenotypic differences between the two ecotypes. We also identified, relative to the near-reference Kanlow population, 17 228 genes present in more copies than in the reference genome (up-CNVs), 112 630 genes present in fewer copies than in the reference genome (down-CNVs) and 14 430 presence/absence variants (PAVs), affecting a total of 9979 genes, including two upland-specific CNV clusters. In total, 45 719 genes were affected by an SNP, CNV, or PAV across the panel, providing a firm foundation to identify functional variation associated with phenotypic traits of interest for biofuel feedstock production.« less

Diversity and population structure of northern switchgrass as revealed through exome capture sequencing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Joseph; Crisovan, Emily; Barry, Kerrie

Panicum virgatum L. (switchgrass) is a polyploid, perennial grass species that is native to North America, and is being developed as a future biofuel feedstock crop. Switchgrass is present primarily in two ecotypes: a northern upland ecotype, composed of tetraploid and octoploid accessions, and a southern lowland ecotype, composed of primarily tetraploid accessions. We employed high-coverage exome capture sequencing (~2.4 Tb) to genotype 537 individuals from 45 upland and 21 lowland populations. From these data, we identified ~27 million single-nucleotide polymorphisms (SNPs), of which 1 590 653 high-confidence SNPs were used in downstream analyses of diversity within and between themore » populations. From the 66 populations, we identified five primary population groups within the upland and lowland ecotypes, a result that was further supported through genetic distance analysis. We identified conserved, ecotype-restricted, non-synonymous SNPs that are predicted to affect the protein function of CONSTANS (CO) and EARLY HEADING DATE 1 (EHD1), key genes involved in flowering, which may contribute to the phenotypic differences between the two ecotypes. We also identified, relative to the near-reference Kanlow population, 17 228 genes present in more copies than in the reference genome (up-CNVs), 112 630 genes present in fewer copies than in the reference genome (down-CNVs) and 14 430 presence/absence variants (PAVs), affecting a total of 9979 genes, including two upland-specific CNV clusters. In total, 45 719 genes were affected by an SNP, CNV, or PAV across the panel, providing a firm foundation to identify functional variation associated with phenotypic traits of interest for biofuel feedstock production.« less

76 FR 58256 - Notice of Application Tendered for Filing With the Commission; Copper Valley Electric Association...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-20

... Application Tendered for Filing With the Commission; Copper Valley Electric Association, Inc. Take notice that..., 2011. d. Applicant: Copper Valley Electric Association, Inc.. e. Name of Project: Allison Creek...: Federal Power Act 16 U.S.C. 791 (a)--825(r) . h. Applicant Contact: Robert A. Wilkinson, CEO, Copper...

Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death.

PubMed

Liu, Sijia; Fu, Chunxiang; Gou, Jiqing; Sun, Liang; Huhman, David; Zhang, Yunwei; Wang, Zeng-Yu

2017-01-01

Switchgrass ( Panicum virgatum ) has been developed into a model lignocellulosic bioenergy crop. Downregulation of caffeic acid O -methyltransferase (COMT), a key enzyme in lignin biosynthesis, has been shown to alter lignification and increase biofuel yield in switchgrass. Methylenetetrahydrofolate reductase (MTHFR) mediates C1 metabolism and provides methyl units consumed by COMT. It was predicted that co-silencing of MTHFR and COMT would impact lignification even more than either of the single genes. However, our results showed that strong downregulation of MTHFR in a COMT -deficient background led to altered plant growth and development, but no significant change in lignin content or composition was found when compared with COMT plants. Another unexpected finding was that the double MTHFR/COMT downregulated plants showed a novel lesion-mimic leaf phenotype. Molecular analyses revealed that the lesion-mimic phenotype was caused by the synergistic effect of MTHFR and COMT genes, with MTHFR playing a predominant role. Microarray analysis showed significant induction of genes related to oxidative and defense responses. The results demonstrated the lack of additive effects of MTHFR and COMT on lignification. Furthermore, this research revealed an unexpected role of the two genes in the modulation of lesion-mimic cell death as well as their synergistic effects on agronomic performance.

Simultaneous Downregulation of MTHFR and COMT in Switchgrass Affects Plant Performance and Induces Lesion-Mimic Cell Death

PubMed Central

Liu, Sijia; Fu, Chunxiang; Gou, Jiqing; Sun, Liang; Huhman, David; Zhang, Yunwei; Wang, Zeng-Yu

2017-01-01

Switchgrass (Panicum virgatum) has been developed into a model lignocellulosic bioenergy crop. Downregulation of caffeic acid O-methyltransferase (COMT), a key enzyme in lignin biosynthesis, has been shown to alter lignification and increase biofuel yield in switchgrass. Methylenetetrahydrofolate reductase (MTHFR) mediates C1 metabolism and provides methyl units consumed by COMT. It was predicted that co-silencing of MTHFR and COMT would impact lignification even more than either of the single genes. However, our results showed that strong downregulation of MTHFR in a COMT-deficient background led to altered plant growth and development, but no significant change in lignin content or composition was found when compared with COMT plants. Another unexpected finding was that the double MTHFR/COMT downregulated plants showed a novel lesion-mimic leaf phenotype. Molecular analyses revealed that the lesion-mimic phenotype was caused by the synergistic effect of MTHFR and COMT genes, with MTHFR playing a predominant role. Microarray analysis showed significant induction of genes related to oxidative and defense responses. The results demonstrated the lack of additive effects of MTHFR and COMT on lignification. Furthermore, this research revealed an unexpected role of the two genes in the modulation of lesion-mimic cell death as well as their synergistic effects on agronomic performance. PMID:28676804

Protection of drinking water reservoirs in buried glacial valleys in the ice-marginal landscape for securing future demand in the European perspective (ENCORE-Project).

NASA Astrophysics Data System (ADS)

Smit, F. W. H.; Bregman, E. P. H.

2012-04-01

Quaternary glaciations have left a significant sedimentological fingerprint in the subsurface of north Europe, in the form of buried glacial valleys. These structures are important drinking water reservoirs for millions of people in the ice-marginal landscape, but are increasingly threatened by anthropogenic pollution (nitrate, sulphate and organic pollutants) and geogenic pollution (salinization). That is one of the conclusion of a recent overview study in the IML of northern Europe from the North Sea to the southern Baltic area. Adequate policy making is yet not possible for several reasons: - Large amounts of data are needed to get a good grip on the lateral continuity of the complex infill. - The BurVal Working Group (2006) has shown that a combination of high resolution seismic survey, together with transient electromagnetic (TEM) surveys can provide realistic data for 3D hydrogeological models. However, these data have not yet been retrieved on a European scale. - Available borehole data can only be used as control points in 3D hydrological models, since the infill of buried glacial valleys is often lateral too complex to make sound interpolations possible. Pollution in buried glacial valleys crosses national borders in northern Europe and therefore national geological surveys have to cooperate in a newly formed European project on protection of these structures. The ENCORE - project (Environmental Conference of the European Regions) has shown in the past that it can facilitate fruitful European cooperation, which is urgently needed due to the costs of gathering data and due to knowledge gaps between different countries. By working together in a European context, these problems can be reduced so that better policy making is possible in order to secure our future drinking water availability.

The use of marker-data transformations to account for linkage disequilibrium in genomic selection: a case study in switchgrass (Panicum virgatum L.)

USDA-ARS?s Scientific Manuscript database

Genomic selection (GS) is an attractive technology to generate rapid genetic gains, particularly in perennial grass species like switchgrass, where phenotyping generally requires at least two years of field trial. In this study, we empirically assessed prediction procedures for GS in two different p...

An exergy based assessment of the production and conversion of switchgrass, equine waste and forest residue to bio-oil using fast pyrolysis

USDA-ARS?s Scientific Manuscript database

The resource efficiency of biofuel production via biomass pyrolysis is evaluated using exergy as an assessment metric. Three feedstocks, important to various sectors of US agriculture, switchgrass, forest residue and equine waste are considered for conversion to bio-oil (pyrolysis oil) via fast pyro...

Isolation and characterization of N2 -fixing bacteria from giant reed and switchgrass for plant growth promotion and nutrient uptake.

PubMed

Xu, Jia; Kloepper, Joseph W; Huang, Ping; McInroy, John A; Hu, Chia H

2018-05-01

The aims of this study were to isolate and characterize N 2 -fixing bacteria from giant reed and switchgrass and evaluate their plant growth promotion and nutrient uptake potential for use as biofertilizers. A total of 190 bacteria were obtained from rhizosphere soil and inside stems and roots of giant reed and switchgrass. All the isolates were confirmed to have nitrogenase activity, 96.9% produced auxin, and 85% produced siderophores. Then the top six strains, including Sphingomonas trueperi NNA-14, Sphingomonas trueperi NNA-19, Sphingomonas trueperi NNA-17, Sphingomonas trueperi NNA-20, Psychrobacillus psychrodurans NP-3, and Enterobacter oryzae NXU-38, based on nitrogenase activity, were inoculated on maize and wheat seeds in greenhouse tests to assess their potential benefits to plants. All the selected strains promoted plant growth by increasing at least one plant growth parameter or increasing the nutrient concentration of maize or wheat plants. NNA-14 outperformed others in promoting early growth and nutrient uptake by maize. Specifically, NNA-14 significantly increased root length, surface area, and fine roots of maize by 14%, 12%, and 17%, respectively, and enhanced N, Ca, S, B, Cu, and Zn in maize. NNA-19 and NXU-38 outperformed others in promoting both early growth and nutrient uptake by wheat. Specifically, NNA-19 significantly increased root dry weight and number of root tips of wheat by 25% and 96%, respectively, and enhanced Ca in wheat. NXU-38 significantly increased root length, surface area, and fine roots of wheat by 21%, 13%, and 26%, respectively, and enhanced levels of Ca and Mg in wheat. It is concluded that switchgrass and giant reed are colonized by N 2 -fixing bacteria that have the potential to contribute to plant growth and nutrient uptake by agricultural crops. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

78 FR 48716 - Notice of Availability of the Final Environmental Impact Statement for the Arkansas Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

... Reservoir to store up to 29,938 acre-feet of water. A long-term storage contract, rather than short-term... Availability of the Final Environmental Impact Statement for the Arkansas Valley Conduit and Long-Term Excess... Valley Conduit (AVC) and Long-Term Excess Capacity Contract, Fryingpan-Arkansas Project, Colorado, is...

Dechlorination of PCBs in the rhizosphere of Switchgrass and Poplar

PubMed Central

Meggo, Richard E.; Schnoor, Jerald L.; Hu, Dingfei

2014-01-01

Polychlorinated biphenyl (PCB) congeners (PCB 52, 77, and 153) singly and in mixture were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks. There was evidence of reductive dechlorination in both planted and unplanted systems, but the planted microcosms with fully developed roots and rhizospheres showed greater biotransformation than the unplanted reactors. These dechlorination products accounted for approximately all of the molar mass of parent compound lost. Based on the transformation products, reductive dechlorination pathways are proposed for rhizospheric biotransformation of PCB 52, 77, and 153. This is the first report of rhizosphere biotransformation pathways for reductive dechlorination in marginally aerobic, intermittently flooded soil as evidenced by a mass balance on transformation products. PMID:23603468

Duck Valley Habitat Enhancement and Protection, 2001-2002 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, Mattie H.; Sellman, Jake

The Duck Valley Indian Reservation's Habitat Enhancement project is an ongoing project designed to enhance and protect critical riparian areas, natural springs, the Owhyee River and its tributaries, and native fish spawning areas on the Reservation. The project commenced in 1997 and addresses the Northwest Power Planning Council's measures 10.8C.2, 10.8C.3, and 10.8C.5 of the 1994 Columbia River Basin Fish and Wildlife Program. The performance period covers dates from April 2001 through August 2002.

Demonstration of Advanced Geophysics and Classification Methods on Munitions Response Sites - East Fork Valley Range Complex, Former Camp Hale

DTIC Science & Technology

2016-04-01

with cores of igneous and metamorphic rocks flanked by steeply dipping sedimentary rocks . The valley floors range in elevation from about 9,310 to...Camp Hale, East Fork Valley Range Complex Munitions Response Site. This project is one in a series of projects funded by ESTCP to use advanced...Technology Certification Program ft Feet FUDS Formerly Used Defense Site GPS Global Positioning System ID Identification IMU Inertial Measurement Unit

The Breakup of Temperature Inversions In Steep Valleys

NASA Astrophysics Data System (ADS)

Colette, A.; Street, R.

The purpose of this research is to model and provide a better understanding of tem- perature inversions breakup in steep valleys. The Advanced Regional Prediction Sys- tem (ARPS), a three-dimensional, compressible, and non-hydrostatic modeling tool developed by the Center for Analysis and Prediction of Storms at the University of Oklahoma was used. Many field studies indicate that the evolution of the convective and inversion layers are strongly dependant on the surrounding topography. In relatively open valleys, the convective boundary layer usually grows from the bottom of the valley while in steeper cases, the upslope morning winds affects the dynamic of the mixing layer resulting in the destruction of the inversion from its bottom and its top (see Whiteman 1980). ARPS allows one to perform accurate simulation of such situations. First, written in terrain following coordinates, it handles steep topographies; then its extensive radi- ation and surface flux packages provide a good treatment of land related processes. Moreover, ARPS accounts for the incidence angle of sunrays, differencing the ex- posed and non-exposed mountain slopes. However, it neglects the topographic shade which can delay the sunrise of a hour or more in steep valleys. A new subroutine described by Colette etal. 2002 is thus used to compute the projected shade on the surrounding topography. Simulations of temperature inversion breakup for various two-dimensional valleys are presented. The time scale of evolution of the mixing layer is in good agreement with field studies and, as expected, the convective boundary layer shows an asymmetry between east and west facing slopes. The different patterns of inversion breakup doc- umented by Whiteman are also reproduced. These simulations of idealized cases give a better understanding of inversion breakup in steep valleys. Our code is now being applied to a real case: the study of a peculiar wind, la Ora del Garda, caused by the interaction between a

Groundwater quality in the Antelope Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

75 FR 44278 - Notice of Availability of the Final Environmental Impact Statement for the Imperial Valley Solar...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-28

... mirrors concentrate solar energy onto the solar receiver of the PCU. The project also includes an..., LVRAB109AA01] Notice of Availability of the Final Environmental Impact Statement for the Imperial Valley Solar... Management Plan (RMP) Amendment/Final Environmental Impact Statement (EIS) for the Imperial Valley Solar, LLC...

A Comparison of Microbial Community Structures by Depth and Season Under Switchgrass

NASA Astrophysics Data System (ADS)

Fansler, S. J.; Smith, J. L.; Bolton, H.; Bailey, V. L.

2008-12-01

As part of a multidisciplinary study of C sequestration in switchgrass production systems, the soil microbial community structure was monitored at 6 different depths (reaching 90 cm) in both spring and autumn. Microbial community structure was assessed using ribosomal intergenic spacer analysis (RISA), and primers were used specific to either bacteria or fungi, generating microbial community fingerprints for each taxonomic group. Diverse microbial communities for both groups were detected throughout the soil profile. It is notable that while community structure clearly changed with depth, there was the deepest soil samples still retained relatively diverse communities. Seasonally, differences are clearly evident within plots at the surface. As the plots were replicated, significant differences in the community fingerprints with depth and season are reported.

Valley Fever (Coccidioidomycosis) Statistics

MedlinePlus

... Valley fever may be under-recognized. 2 , 3 Public health surveillance for Valley fever Valley fever is reportable ... MMWR) . Check with your local, state, or territorial public health department for more information about disease reporting requirements ...

Seasonality and Management Affect Land Surface Temperature Differences Between Loblolly Pine and Switchgrass Ecosystems in Central Virginia

NASA Astrophysics Data System (ADS)

Ahlswede, B.; Thomas, R. Q.; O'Halloran, T. L.; Rady, J.; LeMoine, J.

2017-12-01

Changes in land-use and land management can have biogeochemical and biophysical effects on local and global climate. While managed ecosystems provide known food and fiber benefits, their influence on climate is less well quantified. In the southeastern United States, there are numerous types of intensely managed ecosystems but pine plantations and switchgrass fields represent two biogeochemical and biophysical extremes; a tall, low albedo forest with trees harvested after multiple decades vs. a short, higher albedo C4 grass field that is harvested annually. Despite the wide spread use of these ecosystems for timber and bioenergy, a quantitative, empirical evaluation of the net influence of these ecosystems on climate is lacking because it requires measuring both the greenhouse gas and energy balance of the ecosystems while controlling for the background weather and soil environment. To address this need, we established a pair of eddy flux towers in these ecosystems that are co-located (1.5 km apart) in Central Virginia and measured the radiative energy, non-radiative energy and carbon fluxes, along with associated biometeorology variables; the paired site has run since April 2016. During the first 1.5 years (two growing seasons), we found strong seasonality in the difference in surface temperature between the two ecosystems. In the growing seasons, both sites had similar surface temperature despite higher net radiation in pine. Following harvest of the switchgrass in September, the switchgrass temperatures increased relative to pine. In the winter, the pine ecosystem was warmer. We evaluate the drivers of these intra-annual dynamics and compare the climate influence of these biophysical differences to the differences in carbon fluxes between the sites using a suite of established climate regulation services metrics. Overall, our results show tradeoffs exist between the biogeochemical and biophysical climate services in managed ecosystems in the southeastern United

Microplate-Based Evaluation of the Sugar Yield from Giant Reed, Giant Miscanthus and Switchgrass after Mild Chemical Pre-Treatments and Hydrolysis with Tailored Trichoderma Enzymatic Blends.

PubMed

Cianchetta, Stefano; Bregoli, Luca; Galletti, Stefania

2017-11-01

Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (H 2 SO 4 0.2-2%, w/v) or alkali (NaOH 0.02-0.2%, w/v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R 2  = 0.5), indicating a role for other accessory enzymes.

Valley polarization in bismuth

NASA Astrophysics Data System (ADS)

Fauque, Benoit

2013-03-01

The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

Salton Seismic Imaging Project Line 6: San Andreas Fault and Northern Coachella Valley Structure, Riverside and San Bernardino Counties, California

NASA Astrophysics Data System (ADS)

Catchings, R. D.; Fuis, G.; Rymer, M. J.; Goldman, M.; Tarnowski, J. M.; Hole, J. A.; Stock, J. M.; Matti, J. C.

2012-12-01

The Salton Seismic Imaging Project (SSIP) is a large-scale, active- and passive-source seismic project designed to image the San Andreas fault (SAF) and adjacent basins (Imperial and Coachella Valleys) in southernmost California. Data and preliminary results from many of the seismic profiles are reported elsewhere (including Fuis et al., Rymer et al., Goldman et al., Langenheim et al., this meeting). Here, we focus on SSIP Line 6, one of four 2-D seismic profiles that were acquired across the Coachella Valley. The 44-km-long, SSIP-Line-6 seismic profile extended from the east flank of Mt. San Jacinto northwest of Palm Springs to the Little San Bernardino Mountains and crossed the SAF (Mission Creek (MCF), Banning (BF), and Garnet Hill (GHF) strands) roughly normal to strike. Data were generated by 10 downhole explosive sources (most spaced about 3 to 5 km apart) and were recorded by approximately 347 Texan seismographs (average spacing 126 m). We used first-arrival refractions to develop a P-wave refraction tomography velocity image of the upper crust along the seismic profile. The seismic data were also stacked and migrated to develop low-fold reflection images of the crust. From the surface to about 7 km depth, P-wave velocities range from about 2.5 km/s to about 7.2 km/s, with the lowest velocities within an ~2-km-deep, ~20-km-wide basin, and the highest velocities below the transition zone from the Coachella Valley to Mt. San Jacinto and within the Little San Bernardino Mountains. The BF and GHF strands bound a shallow sub-basin on the southwestern side of the Coachella Valley, but the underlying shallow-depth (~4 km) basement rocks are P-wave high in velocity (~7.2 km/s). The lack of a low-velocity zone beneath BF and GHF suggests that both faults dip northeastward. In a similar manner, high-velocity basement rocks beneath the Little San Bernardino Mountains suggest that the MCF dips vertically or southwestward. However, there is a pronounced low-velocity zone

West Valley demonstration project: Implementation of the kerosene mitigation plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blickwedehl, R.R.; Goodman, J.; Valenti, P.J.

1987-05-01

An aggressive program was implemented to mitigate the migration of radioactive kerosene believed to have originated from the West Valley NRC-Licensed Disposal Area (NDA) disposal trenches designated as SH-10 and SH-11 (Special Holes 10 and 11). This report provides a historical background of the events leading to the migration problem, the results of a detailed investigation to determine the location and source of the kerosene migration, the remediation plan to mitigate the migration, and the actions taken to successfully stabilize the kerosene. 7 refs., 19 figs., 1 tab.

Identification and molecular characterization of the switchgrass AP2/ERF transcription factor superfamily, and overexpression of PvERF001 for improvement of biomass characteristics for biofuel

DOE PAGES

Wuddineh, Wegi A.; Mazarei, Mitra; Turner, Geoffry B.; ...

2015-07-20

The APETALA2/ethylene response factor (AP2/ERF) superfamily of transcription factors (TFs) plays essential roles in the regulation of various growth and developmental programs including stress responses. Members of these TFs in other plant species have been implicated to play a role in the regulation of cell wall biosynthesis. Here, we identified a total of 207 AP2/ERF TF genes in the switchgrass genome and grouped into four gene families comprised of 25 AP2-, 121 ERF-, 55 DREB (dehydration responsive element binding)-, and 5 RAV (related to API3/VP) genes, as well as a singleton gene not fitting any of the above families. Themore » ERF and DREB subfamilies comprised seven and four distinct groups, respectively. Analysis of exon/intron structures of switchgrass AP2/ERF genes showed high diversity in the distribution of introns in AP2 genes versus a single or no intron in most genes in the ERF and RAV families. The majority of the subfamilies or groups within it were characterized by the presence of one or more specific conserved protein motifs. In silico functional analysis revealed that many genes in these families might be associated with the regulation of responses to environmental stimuli via transcriptional regulation of the response genes. Moreover, these genes had diverse endogenous expression patterns in switchgrass during seed germination, vegetative growth, flower development, and seed formation. Interestingly, several members of the ERF and DREB families were found to be highly expressed in plant tissues where active lignification occurs. These results provide vital resources to select candidate genes to potentially impart tolerance to environmental stress as well as reduced recalcitrance. Furthermore, overexpression of one of the ERF genes ( PvERF001) in switchgrass was associated with increased biomass yield and sugar release efficiency in transgenic lines, exemplifying the potential of these TFs in the development of lignocellulosic feedstocks with

Single Parent/Homemaker Project Reports.

ERIC Educational Resources Information Center

Kentucky State Dept. of Education, Frankfort. Office of Vocational Education.

Annual reports, project descriptions, and various other materials are provided for 35 projects. Most of the projects focus on homemaking; some are on sex equity. Project titles include: Single Parent/Adult Homemaker Reentry Program (Ashland Community College); Career Awareness Class for the Single Parent and/or Homemaker (Cumberland Valley Health…

Valley Topological Phases in Bilayer Sonic Crystals

NASA Astrophysics Data System (ADS)

Lu, Jiuyang; Qiu, Chunyin; Deng, Weiyin; Huang, Xueqin; Li, Feng; Zhang, Fan; Chen, Shuqi; Liu, Zhengyou

2018-03-01

Recently, the topological physics in artificial crystals for classical waves has become an emerging research area. In this Letter, we propose a unique bilayer design of sonic crystals that are constructed by two layers of coupled hexagonal array of triangular scatterers. Assisted by the additional layer degree of freedom, a rich topological phase diagram is achieved by simply rotating scatterers in both layers. Under a unified theoretical framework, two kinds of valley-projected topological acoustic insulators are distinguished analytically, i.e., the layer-mixed and layer-polarized topological valley Hall phases, respectively. The theory is evidently confirmed by our numerical and experimental observations of the nontrivial edge states that propagate along the interfaces separating different topological phases. Various applications such as sound communications in integrated devices can be anticipated by the intriguing acoustic edge states enriched by the layer information.

Diurnal Patterns of Heterotrophic and Autotrophic Soil Respiration in Maize and Switchgrass Bioenergy Cropping Systems

NASA Astrophysics Data System (ADS)

von Haden, A.; Marin-Spiotta, E.; Jackson, R. D.; Kucharik, C. J.

2016-12-01

A high proportion of carbon lost from terrestrial ecosystems occurs via soil CO2 respiration. Soil respiration is comprised of two contrasting sources: heterotrophic respiration (RH) from the decomposition of organic matter and autotrophic respiration (RA) from plant root metabolism. Since the two sources of soil respiration vary widely in their origin, the controls of each source are also likely to differ. However, the challenge of partitioning soil respiration sources in situ has limited our mechanistic understanding of RH and RA. Our objective was to evaluate the in situ diurnal controls of RH and RA in maize (Zea mays L.) and switchgrass (Panicum virgatum L.) bioenergy cropping systems. We hypothesized that both RH and RA would follow diurnal soil temperature trends, but that RA would also respond to diel patterns of photosynthetically active radiation (PAR). We also expected that diurnal soil respiration patterns would vary significantly within the growing season. We evaluated our hypothesis with six diurnal soil respiration campaigns during the 2015 and 2016 growing seasons at Arlington, WI, USA. RH showed clear oscillating diel trends, typically peaking in the mid-afternoon when near-surface soil temperatures were highest. Diurnal RA patterns were more nuanced than RH, but were generally highest in the late afternoon and showed the most pronounced diel trends during peak growing season in July. RA also tended to spike in concert with PAR, but this effect was much more prominent in maize than switchgrass. Continuing efforts will attempt to quantitatively separate the effects of soil temperature and PAR on RA.

Optical manipulation of valley pseudospin

DOE PAGES

Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

2016-09-19

The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however,more » remained out of reach. In this paper, we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe 2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. Finally, this study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.« less

An Ecosystem-Based Approach to Valley Oak Mitigation

Treesearch

Marcus S. Rawlings; Daniel A. Airola

1997-01-01

The Contra Costa Water District’s (CCWD’s) Los Vaqueros Reservoir Project will inundate 180 acres of valley oak habitats. Instead of using replacement ratios to identify mitigation needs, we designed an approach that would efficiently replace lost ecological values. We developed a habitat quality index model to assess the value of lost wildlife habitat and...

Hazard connected to tunnel construction in Mt Stena karstic area (Rosandra Valley, Classical Karst)

NASA Astrophysics Data System (ADS)

Cucchi, F.; Boschin, W.; Visintin, L.; Zini, L.

2009-04-01

Rosandra Valley -a unique geomorphological environment- is located in the western side of the Classical Karst plateau. This deep limestone gorge is crossed by a stream that is fed by a large basin located in Slovenia. Rosandra Valley is the only example of Classical Karst river valley with surface hydrography; the torrent digs a deep gully into the rock, rich in rapids, swirl holes, small waterfalls, enclosed meanders and basins; here, the first seepage phenomena occur, and part of the water feeds the underground aquifer. Rosandra Valley is theatre to complex structural situation; the NE slope culminates in the structure of Mt Stena, a limestone tectonic scale located between two faults and firmly rooted in the karst platform. Tectonics is quite important for the development of deep karst in this area; Mt Stena, in particular, hosts a comprehensive net of articulated and diversely shaped caves, basically organised on several levels, which stretches over a total of 9,000 metres, bearing testimony to ancient geological and hydrogeological origins. The deepest areas of the system reach a suspended aquifer that is probably sustained by an overthrust and placed about 100 meters above Rosandra torrent underground aquifer. During feasibility studies about Trieste-Divača high velocity railway link, interaction between project and karst features was examined; in fact the proximity of proposal project and Mt Stena karst system suggest to improve the knowledge related to karst and hydrogeological aspects of the massif. Compatibly with the project requirements, risk of voids intersection and water contamination were analyzed. In fact the Mt Stena suspended aquifer partially feeds Rosandra torrent which flows in a protected natural area. Karst features were represented in a 3D model in order to better understand the spatial relationship between railway project and karst system.

Central Avra Valley Storage and Recovery Project (CAVSARP) Site, Tucson, Arizona: Floodwater and Soil Moisture Investigations with Extraterrestrial Applications

NASA Technical Reports Server (NTRS)

Rucker, D. F.; Dohm, J. M.; Ferre, T. P. A.; Ip, Felipe; Baker, V. R.; Davies, A. G.; Castano, R.; Chien, S.; Doggett, T. C.

2004-01-01

Planetary geologists, geomorphologists, and hydrologists have hypothesized that Mars is a dynamic, water-enriched planet since the Mariner and Viking missions based on geologic, geomorphic, and topographic information. Recent acquisition of Gamma Ray and Neutron Spectrometer information has added further credence to this hypothesis. A unique investigation is underway to work towards being able to successfully map the extent and depth of water on Mars. Researchers from the University of Arizona and members of the Autonomous Sciencecraft Experiment (ASE) have been compiling multiple layers of information in time and space at the Central Avra Valley Storage and Recovery Project (CAVSARP) site, Tucson, Arizona, for eventual comparative analysis. This information has been acquired from a variety of observational/scientific platforms in controlled conditions. CAVSARP facility:

New Ancient Egyptian Human Mummies from the Valley of the Kings, Luxor: Anthropological, Radiological, and Egyptological Investigations.

PubMed

Rühli, Frank; Ikram, Salima; Bickel, Susanne

2015-01-01

The Valley of the Kings (arab. Wadi al Muluk; KV) situated on the West Bank near Luxor (Egypt) was the site for royal and elite burials during the New Kingdom (ca. 1500-1100 BC), with many tombs being reused in subsequent periods. In 2009, the scientific project "The University of Basel Kings' Valley Project" was launched. The main purpose of this transdisciplinary project is the clearance and documentation of nonroyal tombs in the surrounding of the tomb of Pharaoh Thutmosis III (ca. 1479-1424 BC; KV 34). This paper reports on newly discovered ancient Egyptian human mummified remains originating from the field seasons 2010-2012. Besides macroscopic assessments, the remains were conventionally X-rayed by a portable X-ray unit in situ inside KV 31. These image data serve as basis for individual sex and age determination and for the study of probable pathologies and embalming techniques. A total of five human individuals have been examined so far and set into an Egyptological context. This project highlights the importance of ongoing excavation and science efforts even in well-studied areas of Egypt such as the Kings' Valley.

San Diego Gas and Electric Company Imperial Valley geothermal activities

NASA Technical Reports Server (NTRS)

Hinrichs, T. C.

1974-01-01

San Diego Gas and Electric and its wholly owned subsidiary New Albion Resources Co. have been affiliated with Magma Power Company, Magma Energy Inc. and Chevron Oil Company for the last 2-1/2 years in carrying out geothermal research and development in the private lands of the Imperial Valley. The steps undertaken in the program are reviewed and the sequence that must be considered by companies considering geothermal research and development is emphasized. Activities at the south end of the Salton Sea and in the Heber area of Imperial Valley are leading toward development of demonstration facilities within the near future. The current status of the project is reported.

Evolution of collapse valleys in karst - examples from the Carpatho-Balkanides of Serbia

NASA Astrophysics Data System (ADS)

Petrović, Aleksandar S.; Ćalić, Jelena; Spalević, Aleksandra; Pantić, Marko

2016-04-01

Development of valleys in karst is an issue which has not been sufficiently studied in karst surface morphology. THESE valleys are long linear forms whose orthogonal projections resemble normal valleys, but most of their characteristics are strongly influenced by karst process. In largest number of relevant references, this subject is either only briefly mentioned or completely lacking. This paper presents the examples of a particular type of valley in karst formed by cave ceiling collapse close to the topographical surface. Karst of the Carpatho-Balkanides in eastern Serbia is characterized by uneven spatial distribution in several large massifs, but also in a large number of relatively small outcrops (patches and belts), which enable the development of contact karst and fluviokarst. Many morphological elements are of fluvial origin, subsequently modified by karst process. Collapse valleys occur mostly at the downstream contacts (where a seasonal watercourse leaves limestones) or in karst/limestone belts. In the first phase, which is visible on the example of the Radovanska Reka, the river course sinks to the swallets in the riverbed and forms a blind valley. After sinking, the water flows through the tunnel cave, while largest part of the valley remains above the cave. The bottom of the dry valley is dissected by deep dolines, reaching almost to the cave roof. In this part of the study, the area was scanned by a multistation Leica Nova MS 50 (resolution 20 cm @ 10 m). In the second phase, the doline bottoms reach the cave ceilings which develop holes at certain points, as it is case at the Zamna River valley. These hollows tend to enlarge with time, and the surface of the cave ceiling is reduced. The third, final phase is characterised by collapse of larger segments of cave ceilings. Only the natural bridges remain, as the remnants of former caves (e.g. in the Vratna River valley, Ravna Reka valley). These parts of valleys in karst are usually narrow, steep

Status and understanding of groundwater quality in the Santa Clara River Valley, 2007-California GAMA Priority Basin Project

USGS Publications Warehouse

Burton, Carmen A.; Montrella, Joseph; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

Groundwater quality in the approximately 460-square-mile Santa Clara River Valley study unit was investigated from April through June 2007 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. The Santa Clara River Valley study unit contains eight groundwater basins located in Ventura and Los Angeles Counties and is within the Transverse and Selected Peninsular Ranges hydrogeologic province. The Santa Clara River Valley study unit was designed to provide a spatially unbiased assessment of the quality of untreated (raw) groundwater in the primary aquifer system. The assessment is based on water-quality and ancillary data collected in 2007 by the USGS from 42 wells on a spatially distributed grid, and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer system was defined as that part of the aquifer system corresponding to the perforation intervals of wells listed in the CDPH database for the Santa Clara River Valley study unit. The quality of groundwater in the primary aquifer system may differ from that in shallow or deep water-bearing zones; for example, shallow groundwater may be more vulnerable to surficial contamination. Eleven additional wells were sampled by the USGS to improve understanding of factors affecting water quality.The status assessment of the quality of the groundwater used data from samples analyzed for anthropogenic constituents, such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents, such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources in the primary aquifers of the Santa Clara River Valley study unit

Impact of pretreated Switchgrass and biomass carbohydrates on Clostridium thermocellum ATCC 27405 cellulosome composition: a quantitative proteomic analysis.

PubMed

Raman, Babu; Pan, Chongle; Hurst, Gregory B; Rodriguez, Miguel; McKeown, Catherine K; Lankford, Patricia K; Samatova, Nagiza F; Mielenz, Jonathan R

2009-01-01

Economic feasibility and sustainability of lignocellulosic ethanol production requires the development of robust microorganisms that can efficiently degrade and convert plant biomass to ethanol. The anaerobic thermophilic bacterium Clostridium thermocellum is a candidate microorganism as it is capable of hydrolyzing cellulose and fermenting the hydrolysis products to ethanol and other metabolites. C. thermocellum achieves efficient cellulose hydrolysis using multiprotein extracellular enzymatic complexes, termed cellulosomes. In this study, we used quantitative proteomics (multidimensional LC-MS/MS and (15)N-metabolic labeling) to measure relative changes in levels of cellulosomal subunit proteins (per CipA scaffoldin basis) when C. thermocellum ATCC 27405 was grown on a variety of carbon sources [dilute-acid pretreated switchgrass, cellobiose, amorphous cellulose, crystalline cellulose (Avicel) and combinations of crystalline cellulose with pectin or xylan or both]. Cellulosome samples isolated from cultures grown on these carbon sources were compared to (15)N labeled cellulosome samples isolated from crystalline cellulose-grown cultures. In total from all samples, proteomic analysis identified 59 dockerin- and 8 cohesin-module containing components, including 16 previously undetected cellulosomal subunits. Many cellulosomal components showed differential protein abundance in the presence of non-cellulose substrates in the growth medium. Cellulosome samples from amorphous cellulose, cellobiose and pretreated switchgrass-grown cultures displayed the most distinct differences in composition as compared to cellulosome samples from crystalline cellulose-grown cultures. While Glycoside Hydrolase Family 9 enzymes showed increased levels in the presence of crystalline cellulose, and pretreated switchgrass, in particular, GH5 enzymes showed increased levels in response to the presence of cellulose in general, amorphous or crystalline. Overall, the quantitative results

Chuckwalla Valley multiple-well monitoring site, Chuckwalla Valley, Riverside County

USGS Publications Warehouse

Everett, Rhett

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, is evaluating the geohydrology and water availability of the Chuckwalla Valley, California. As part of this evaluation, the USGS installed the Chuckwalla Valley multiple-well monitoring site (CWV1) in the southeastern portion of the Chuckwalla Basin. Data collected at this site provide information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus enhancing the understanding of the geohydrologic framework of the Chuckwalla Valley. This report presents construction information for the CWV1 multiple-well monitoring site and initial geohydrologic data collected from the site.

Groundwater quality in the Owens Valley, California

USGS Publications Warehouse

Dawson, Barbara J. Milby; Belitz, Kenneth

2012-01-01

Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

78 FR 27071 - Approval and Promulgation of Air Quality Implementation Plans; Alaska: Mendenhall Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-09

... lungs and cause serious adverse health effects. People with heart or lung diseases, children and older...) submitted with the Mendenhall Valley NAA PM 10 LMP, for base year 2004 and projected year 2018, identifies... projected to remain close to that level through 2018. Fugitive dust emissions from travel on unpaved roads...

Groundwater quality in the Northern Sacramento Valley, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Northern Sacramento Valley is one of the study units being evaluated.

Groundwater quality in the Southern Sacramento Valley, California

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The Southern Sacramento Valley is one of the study units being evaluated.

Application of the Evacuated Canister System for Removing Residual Molten Glass From the West Valley Demonstration Project High-Level Waste Melter

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Joseph J.; Dombrowski, David J.; Valenti, Paul J.

The principal mission of the West Valley Demonstration Project (WVDP) is to meet a series of objectives defined in the West Valley Demonstration Project Act (Public Law 96-368). Chief among these is the objective to solidify liquid high-level waste (HLW) at the WVDP site into a form suitable for disposal in a federal geologic repository. In 1982, the Secretary of Energy formally selected vitrification as the technology to be used to solidify HLW at the WVDP. One of the first steps in meeting the HLW solidification objective involved designing, constructing and operating the Vitrification (Vit) Facility, the WVDP facility thatmore » houses the systems and subsystems used to process HLW into stainless steel canisters of borosilicate waste-glass that satisfy waste acceptance criteria (WAC) for disposal in a federal geologic repository. HLW processing and canister production began in 1996. The final step in meeting the HLW solidification objective involved ending Vit system operations and shut ting down the Vit Facility. This was accomplished by conducting a discrete series of activities to remove as much residual material as practical from the primary process vessels, components, and associated piping used in HLW canister production before declaring a formal end to Vit system operations. Flushing was the primary method used to remove residual radioactive material from the vitrification system. The inventory of radioactivity contained within the entire primary processing system diminished by conducting the flushing activities. At the completion of flushing activities, the composition of residual molten material remaining in the melter (the primary system component used in glass production) consisted of a small quantity of radioactive material and large quantities of glass former materials needed to produce borosilicate waste-glass. A special system developed during the pre-operational and testing phase of Vit Facility operation, the Evacuated Canister System (ECS

Detailed study of selenium and other constituents in water, bottom sediment, soil, alfalfa, and biota associated with irrigation drainage in the Uncompahgre Project area and in the Grand Valley, west-central Colorado, 1991-93

USGS Publications Warehouse

Butler, D.L.; Wright, W.G.; Stewart, K.C.; Osmundson, B.C.; Krueger, R.P.; Crabtree, D.W.

1996-01-01

In 1985, the U.S. Department of the Interior began a program to study the effects of irrigation drainage in the Western United States. These studies were done to determine whether irrigation drainage was causing problems related to human health, water quality, and fish and wildlife resources. Results of a study in 1991-93 of irrigation drainage associated with the Uncompahgre Project area, located in the lower Gunnison River Basin, and of the Grand Valley, located along the Colorado River, are described in this report. The focus of the report is on the sources, distribution, movement, and fate of selenium in the hydrologic and biological systems and the effects on biota. Generally, other trace- constituent concentrations in water and biota were not elevated or were not at levels of concern. Soils in the Uncompahgre Project area that primarily were derived from Mancos Shale contained the highest concentrations of total and watrer-extractable selenium. Only 5 of 128\\x11alfalfa samples had selenium concentrations that exceeded a recommended dietary limit for livestock. Selenium data for soil and alfalfa indicate that irrigation might be mobilizing and redistributing selenium in the Uncompahgre Project area. Distribution of dissolved selenium in ground water is affected by the aqueous geochemical environment of the shallow ground- water system. Selenium concentrations were as high as 1,300\\x11micrograms per liter in water from shallow wells. The highest concentrations of dissolved selenium were in water from wells completed in alluvium overlying the Mancos Shale of Cretaceous age; selenium concentrations were lower in water from wells completed in Mancos Shale residuum. Selenium in the study area could be mobilized by oxidation of reduced selenium, desorption from aquifer sediments, ion exchange, and dissolution. Infiltration of irrigation water and, perhaps nitrate, provide oxidizing conditions for mobilization of selenium from alluvium and shale residuum and for

Potential effects of drought on carrying capacity for wintering waterfowl in the Central Valley of California

USGS Publications Warehouse

Petrie, Mark J.; Fleskes, Joseph P.; Wolder, Mike A.; Isola, Craig R.; Yarris, Gregory S.; Skalos, Daniel A.

2016-01-01

We used the bioenergetics model TRUEMET to evaluate potential effects of California's recent drought on food supplies for waterfowl wintering in the Central Valley under a range of habitat and waterfowl population scenarios. In nondrought years in the current Central Valley landscape, food supplies are projected to be adequate for waterfowl from fall through early spring (except late March) even if waterfowl populations reach North American Waterfowl Management Plan goals. However, in all drought scenarios that we evaluated, food supplies were projected to be exhausted for ducks by mid- to late winter and by late winter or early spring for geese. For ducks, these results were strongly related to projected declines in winter-flooded rice fields that provide 45% of all the food energy available to ducks in the Central Valley in nondrought water years. Delayed flooding of some managed wetlands may help alleviate food shortages by providing wetland food resources better timed with waterfowl migration and abundance patterns in the Central Valley, as well as reducing the amount of water needed to manage these habitats. However, future research is needed to evaluate the impacts of delayed flooding on waterfowl hunting, and whether California's existing water delivery system would make delayed flooding feasible. Securing adequate water supplies for waterfowl and other wetland-dependent birds is among the greatest challenges facing resource managers in coming years, especially in the increasingly arid western United States.

Data for ground-water test hole near Nicolaus, Central Valley aquifer project, California

USGS Publications Warehouse

French, James J.; Page, R.W.; Bertoldi, Gilbert L.

1983-01-01

Preliminary data are provided for the third of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 2, T.12N., R.3E., Sutter County, California, about 1 1/2 miles northwest of the town of Nicolaus. Drilled to a depth of 1,150 feet below land surface, the hole is cased to a depth of 100 feet and equipped with three piezometer tubes to depths of 311, 711, and 1,071 feet. A 5-foot well screen is set in sand at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer, and the well bore is filled between the plugs with sediment. Thirty-one cores and 34 sidewall cores were recovered. Laboratory tests were made for minerology, consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis of the three tapped zones and measured for water level. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

75 FR 62852 - Notice of Availability of the Record of Decision for the Chevron Energy Solutions Lucerne Valley...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-13

...-way (ROW) authorization to construct and operate a 45-megawatt (MW) solar photovoltaic project which... Solar Project, California and the Approved Plan Amendment to the California Desert Conservation Area...) Lucerne Valley Solar Project located in San Bernardino County, California. The Secretary of the Interior...

Education Outreach Associated with Technology Transfer in a Colonia of South Texas: Green Valley Farms Science and Space Club for Middle School Aged Children in Green Valley Farms, San Benito, Texas

NASA Technical Reports Server (NTRS)

Potess, Marla D.; Rainwater, Ken; Muirhead, Dean

2004-01-01

Texas colonias are unincorporated subdivisions characterized by inadequate water and wastewater infrastructure, inadequate drainage and road infrastructure, substandard housing, and poverty. Since 1989 the Texas Legislature has implemented policies to halt further development of colonias and to address water and wastewater infrastructure needs in existing and new colonias along the border with Mexico. Government programs and non-government and private organization projects aim to address these infrastructure needs. Texas Tech University's Water Resources Center demonstrated the use of alternative on-site wastewater treatment in the Green Valley Farms colonia, San Benito, Texas. The work in Green Valley Farms was a component of a NASA-funded project entitled Evaluation of NASA's Advanced Life Support Integrated Water Recovery System for Non-Optimal Conditions and Terrestrial Applications. Two households within the colonia are demonstration sites for constructed wetlands. A colonia resident and activist identified educational opportunities for colonia children as a primary goal for many colonia residents. Colonia parents view education as the door to opportunity and escape from poverty for their children. The educational outreach component of the project in Green Valley Farms was a Science and Space Club for middle-school age students. Involved parents, schoolteachers, and school administrators enthusiastically supported the monthly club meetings and activities. Each month, students participated in interactive learning experiences about water use and reuse in space and on earth. Activities increased knowledge and interest in water resource issues and in science and engineering fields. The Institute for the Development and Enrichment of Advanced Learners (IDEAL) at Texas Tech University provided full scholarships for five students from Green Valley Farms to attend the Shake Hands With Your Future camp at Texas Tech University in June 2003. The educational outreach

Observation of acoustic valley vortex states and valley-chirality locked beam splitting

NASA Astrophysics Data System (ADS)

Ye, Liping; Qiu, Chunyin; Lu, Jiuyang; Wen, Xinhua; Shen, Yuanyuan; Ke, Manzhu; Zhang, Fan; Liu, Zhengyou

2017-05-01

We report an experimental observation of the classical version of valley polarized states in a two-dimensional hexagonal sonic crystal. The acoustic valley states, which carry specific linear momenta and orbital angular momenta, were selectively excited by external Gaussian beams and conveniently confirmed by the pressure distribution outside the crystal, according to the criterion of momentum conservation. The vortex nature of such intriguing bulk crystal states was directly characterized by scanning the phase profile inside the crystal. In addition, we observed a peculiar beam-splitting phenomenon, in which the separated beams are constructed by different valleys and locked to the opposite vortex chirality. The exceptional sound transport, encoded with valley-chirality locked information, may serve as the basis of designing conceptually interesting acoustic devices with unconventional functions.

Climatic and morphological controls on post-glacial lake and river valley evolution in the Weichselian belt - an example from the Wda valley, Northern Poland

NASA Astrophysics Data System (ADS)

Kramkowski, M. A.; Błaszkiewicz, M.; Piotrowski, J. A.; Brauer, A.; Gierszewski, P.; Kordowski, J.; Lamparski, P.; Lorenz, S.; Noryśkiewicz, A. M.; Ott, F.; Slowinski, M. M.; Tyszkowski, S.

2014-12-01

The River Wda valley is a classical example of a polygenetic valley, consisting of former lake basins joined by erosive gap sections. In its middle section, which was the subject of our research, a fragment of an abandoned Lateglacial river valley is preserved, which is unique for the Weichselian moraine belt in the Central European Lowlands. The analysis of the relationship between the lacustrine and fluvial sediments and landforms enabled the authors to report many evolutionary connections between the initial period of the river system formation and the emergence of lakes during the Weichselian Lateglacial. The surface drainage essentially determined the progress of melting of dead ice blocks buried in the glacial depressions, which finally led to lake formation there. Most of the lake basins in the study area were formed during the Bølling-Allerød period. However, one section of the subglacial channel was not exposed to the thermokarst conditions and was therefore preserved with dead ice blocks throughout the entire Lateglacial. The dead ice decay at the beginning of the Holocene, as well as the emergence of another lake, created a lower base level of erosion in the close vicinity of the abandoned valley and induced a change of the river's course. Both fluvial and lacustrine deposits and landforms distributed in the central section of the River Wda valley indicate two processes, which proceeded simultaneously: (1) emergence of fluvially joined lake basins within a glacial channel, (2) degradation of the river bed in the gap sections interfering between the lakes. The processes described for the central section of the River Wda channel indicate a very dynamic river valley development during the Weichselian Lateglacial and the early Holocene. The valley formation was tightly interwoven with the morphogenesis of the primary basins within the valley, mainly with the melting of the buried blocks of dead ice and the development of lakes. This study is a contribution

Dry Valleys, Antarctica

NASA Image and Video Library

2009-11-02

The McMurdo Dry Valleys are a row of valleys west of McMurdo Sound, Antarctica. They are so named because of their extremely low humidity and lack of snow and ice cover. This image was acquired December 8, 2002 by NASA Terra spacecraft.

Integrated omics analyses reveal the details of metabolic adaptation of Clostridium thermocellum to lignocellulose-derived growth inhibitors released during the deconstruction of switchgrass.

PubMed

Poudel, Suresh; Giannone, Richard J; Rodriguez, Miguel; Raman, Babu; Martin, Madhavi Z; Engle, Nancy L; Mielenz, Jonathan R; Nookaew, Intawat; Brown, Steven D; Tschaplinski, Timothy J; Ussery, David; Hettich, Robert L

2017-01-01

Clostridium thermocellum is capable of solubilizing and converting lignocellulosic biomass into ethanol. Although much of the work-to-date has centered on characterizing this microbe's growth on model cellulosic substrates, such as cellobiose, Avicel, or filter paper, it is vitally important to understand its metabolism on more complex, lignocellulosic substrates to identify relevant industrial bottlenecks that could undermine efficient biofuel production. To this end, we have examined a time course progression of C. thermocellum grown on switchgrass to assess the metabolic and protein changes that occur during the conversion of plant biomass to ethanol. The most striking feature of the metabolome was the observed accumulation of long-chain, branched fatty acids over time, implying an adaptive restructuring of C. thermocellum's cellular membrane as the culture progresses. This is undoubtedly a response to the gradual accumulation of lignocellulose-derived inhibitory compounds as the organism deconstructs the switchgrass to access the embedded cellulose. Corroborating the metabolomics data, proteomic analysis revealed a corresponding time-dependent increase in various enzymes, including those involved in the interconversion of branched amino acids valine, leucine, and isoleucine to iso- and anteiso-fatty acid precursors. Additionally, the metabolic accumulation of hemicellulose-derived sugars and sugar alcohols concomitant with increased abundance of enzymes involved in C5 sugar metabolism/pentose phosphate pathway indicates that C. thermocellum shifts glycolytic intermediates to alternate pathways to modulate overall carbon flux in response to C5 sugar metabolites that increase during lignocellulose deconstruction. Integrated omic platforms provided complementary systems biological information that highlight C. thermocellum 's specific response to cytotoxic inhibitors released during the deconstruction and utilization of switchgrass. These additional viewpoints

Hydrogen production from switchgrass via an integrated pyrolysis-microbial electrolysis process.

PubMed

Lewis, A J; Ren, S; Ye, X; Kim, P; Labbe, N; Borole, A P

2015-11-01

A new approach to hydrogen production using an integrated pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L anode-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50±3.2% to 76±0.5% while anode Coulombic efficiency ranged from 54±6.5% to 96±0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%, respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process

DOE PAGES

Lewis, Alex J.; Ren, Shoujie; Ye, Philip; ...

2015-06-30

A new approach to hydrogen production using a hybrid pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50 3.2% to76 0.5% while anode coulombic efficiency ranged from 54 6.5% to 96 0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%,more » respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass.« less

Transboundary Contributions To Surface Ozone In California's Central Valley

NASA Astrophysics Data System (ADS)

Post, A.; Faloona, I. C.; Conley, S. A.; Lighthall, D.

2014-12-01

Rising concern over the impacts of exogenous air pollution in California's Central Valley has prompted the establishment of a coastal, high altitude monitoring site at the Chews Ridge Observatory (1550 m) approximately 30 km east of Point Sur in Monterey County, under the auspices of the Monterey Institute for Research in Astronomy. Two and a half years of continuous ozone data are presented in the context of long-range transport and its potential impact on surface air quality in the San Joaquin Valley (SJV). Past attempts to quantify the impact of transboundary ozone on surface levels have relied on uncertain model estimates, or have been limited to weekly ozonesonde data. Here, we present an observationally derived quantification of the contribution of free tropospheric ozone to surface sites in the San Joaquin Valley throughout three ozone seasons (June through September, 2012-2014). The diurnal ozone patterns at Chews Ridge, and their correlations with ozone aloft over the Valley, have been presented previously. Furthermore, reanalysis data of geopotential heights indicate consistent flow from Chews Ridge to the East, directly over the SJV. In a related airborne project we quantify the vertical exchange, or entrainment, rate over the Southern SJV from a series of focused flights measuring ozone concentrations during peak photochemical hours in conjunction with local meteorological data to quantify an ozone budget for the area. By applying the entrainment rates observed in that study here we are able to quantify the seasonal contributions of free tropospheric ozone measured at Chews Ridge to surface sites in the San Joaquin Valley, and compare prior model estimates to our observationally derived values.

California Freshwater Shrimp Project: An Eco-Action Project with Real Life Learning.

ERIC Educational Resources Information Center

Rogers, Laurette H.

The California Freshwater Shrimp Project is an example of a student-initiated, eco-action project. Students, from a fourth grade class in the Ross Valley School District in San Rafael, California, were linked to their community and environment through their work in rehabilitating habitat and educating the public. The paper gives an overview of a…

Intelligent transportation systems deployment project for the Ada County Highway District FY99 Treasure Valley ITS : final self evaluation report

DOT National Transportation Integrated Search

2004-11-01

In 1999, the Treasure Valley area of the State of Idaho received a federal earmark of $441,470 to develop an Incident Management Plan for the Treasure Valley and to design/deploy Intelligent Transportation Systems (ITS) devices for Interstates 84 and...

Mapping Ecosystem Services in the Jordan Valley, Jordan

NASA Astrophysics Data System (ADS)

Luz, Ana; Marques, Ana; Ribeiro, Inês; Alho, Maria; Catarina Afonso, Ana; Almeida, Erika; Branquinho, Cristina; Talozi, Samer; Pinho, Pedro

2016-04-01

In the last decade researchers started using ecosystem services as a new framework to understand the relationships between environment and society. Habitat quality and water quality are related with ecosystem services regulation and maintenance, or even provision. According to the Common International Classification of Ecosystem Services (CICES) both habitat quality and water quality are associated with lifecycle maintenance, habitat and gene pool protection, and water conditions, among others. As there is increased pressure on habitats and rivers especially for agricultural development, mapping and evaluating habitat and water quality has important implications for resource management and conservation, as well as for rural development. Here, we model and map habitat and water quality in the Jordan Valley, Jordan. In this study, we aim to identify and analyse ecosystem services both through 1) habitat quality and 2) water quality modelling using InVest, an integrated valuation of ecosystem services and tradeoffs. The data used in this study mainly includes the LULC, Jordan River watershed and main threats and pollutants in the study area, such as agriculture, industry, fish farms and urbanization. Results suggest a higher pressure on natural habitats in the Northern region of the Jordan Valley, where industry is dominant. Agriculture is present along the Jordan Valley and limits the few natural forested areas. Further, water pollution is mainly concentrated in disposal sites due to the low flow of the Jordan River. Our results can help to identify areas where natural resources and water resource management is most needed in the Jordan Valley. Acknowledgements: Transbasin FP7 project

Transforming the "Valley of Death" into a "Valley of Opportunity"

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Merceret, Francis J.; O'Brien, T. P.; Roeder, William P.; Huddleston, Lisa L.; Bauman, William H., III

2014-01-01

Transitioning technology from research to operations (23 R2O) is difficult. The problem's importance is exemplified in the literature and in every failed attempt to do so. Although the R2O gap is often called the "valley of death", a recent a Space Weather editorial called it a "Valley of Opportunity". There are significant opportunities for space weather organizations to learn from the terrestrial experience. Dedicated R2O organizations like those of the various NOAA testbeds and collaborative "proving ground" projects take common approaches to improving terrestrial weather forecasting through the early transition of research capabilities into the operational environment. Here we present experience-proven principles for the establishment and operation of similar space weather organizations, public or private. These principles were developed and currently being demonstrated by NASA at the Applied Meteorology Unit (AMU) and the Short-term Prediction Research and Transition (SPoRT) Center. The AMU was established in 1991 jointly by NASA, the U.S. Air Force (USAF) and the National Weather Service (NWS) to provide tools and techniques for improving weather support to the Space Shuttle Program (Madura et al., 2011). The primary customers were the USAF 45th Weather Squadron (45 WS) and the NWS Spaceflight Meteorology Group (SMG who provided the weather observing and forecast support for Shuttle operations). SPoRT was established in 2002 to transition NASA satellite and remote-sensing technology to the NWS. The continuing success of these organizations suggests the common principles guiding them may be valuable for similar endeavors in the space weather arena.

Analysis of Mining-induced Valley Closure Movements

NASA Astrophysics Data System (ADS)

Zhang, C.; Mitra, R.; Oh, J.; Hebblewhite, B.

2016-05-01

Valley closure movements have been observed for decades in Australia and overseas when underground mining occurred beneath or in close proximity to valleys and other forms of irregular topographies. Valley closure is defined as the inward movements of the valley sides towards the valley centreline. Due to the complexity of the local geology and the interplay between several geological, topographical and mining factors, the underlying mechanisms that actually cause this behaviour are not completely understood. A comprehensive programme of numerical modelling investigations has been carried out to further evaluate and quantify the influence of a number of these mining and geological factors and their inter-relationships. The factors investigated in this paper include longwall positional factors, horizontal stress, panel width, depth of cover and geological structures around the valley. It is found that mining in a series passing beneath the valley dramatically increases valley closure, and mining parallel to valley induces much more closure than other mining orientations. The redistribution of horizontal stress and influence of mining activity have also been recognised as important factors promoting valley closure, and the effect of geological structure around the valley is found to be relatively small. This paper provides further insight into both the valley closure mechanisms and how these mechanisms should be considered in valley closure prediction models.

The Inter-Valley Soil Comparative Survey: the ecology of Dry Valley edaphic microbial communities