Source: PURDUE UNIVERSITY submitted to NRP
COMPARATIVE BIOFUEL PRODUCTIVITY AND CARBON, NITROGEN, AND WATER ECONOMIES OF SWITCHGRASS, MISCANTHUS, MAIZE, SORGHUM, AND A LOW-INPUT, BIG BL
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0213981
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2008
Project End Date
Sep 30, 2013
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
PURDUE UNIVERSITY
(N/A)
WEST LAFAYETTE,IN 47907
Performing Department
Agronomy
Non Technical Summary
Current U.S. plans for energy security rely on the conversion of large acreages from food crop production to the production of cellulosic biomass in order to produce 86 billion gallons of biofuels thereby reducing our dependence on imported oil by 25% by 2025. Additionally, lands currently considered too marginal for intensive food production may be considered suitable for biofuel production bringing highly erodible, nutrient poor soils currently in conservation reserve programs back into intensive agriculture. In the Midwest, cropping systems may shift from the predominant corn - soybean base to a more varied array of species including novel perennial grasses for which little agronomic and environmental data exist. Optimizing nutrient use efficiency will be essential to mitigating the environmental damage associated with fertilizer production and application where improper management can result in nutrient runoff into lakes, river systems and oceans and production of greenhouse gases. Likewise, understanding crop water balance and optimizing water use efficiency will be essential to bioenergy crop success as water resources are expected to be the single, most-limiting factor in the multiple regions of the U.S. where biofuel production will be pursued. Sustainable biofuels production with the concomitant protection and improvement of air, soil and water resources requires a concerted effort by the scientific community to gain knowledge regarding the comparative energy production potentials and environmental impacts of candidate biofuel systems. We propose to conduct comparative analyses of the productivity potential and the environmental impacts of the most promising bioenergy crops and management systems at Purdue University's Water Quality Field Station (WQFS). Project team expertise combined with the unique WQFS capabilities for quantifying agriculture's environmental footprint will permit a quantitative assessment of candidate system net energy balance. The primary outcome of this research will be the establishment of a new, interdisciplinary research effort at Purdue University focused on the environmental consequences of the explosive growth in bioenergy crops.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1022299107060%
2032299102040%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 203 - Plant Biological Efficiency and Abiotic Stresses Affecting Plants;

Subject Of Investigation
2299 - Miscellaneous and new crops, general/other;

Field Of Science
1070 - Ecology; 1020 - Physiology;
Goals / Objectives
Our overall goal is to develop a cropping system-level analysis of the potential for Miscanthus, switchgrass, maize-based and low-input native prairie production systems to provide renewable fuel while protecting natural resources. Our hypothesis is that candidate biofuel cropping systems differ in total yield and yield of structural and non-structural carbohydrate pools that determine profitability, but that candidate systems also differ in water, N, and C economies; these differences will drive changes in soil, water and air quality that, in turn, determine the scope and nature of environmental impacts and sustainability. Specific objectives are to: 1) determine the comparative environmental impacts of switchgrass, Miscanthus, maize (grain and grain plus stover removal), and low-input big bluestem including the assessment of: a) cropping system impact on soil storage (sequestration) of C and N; b) cropping system impact on nitrate and dissolved organic carbon edge-of-field loss to water as facilitated by artificial tile drainage, and c) cropping system impact on greenhouse gas emissions. 2) determine the comparative biofuels feedstock potential of switchgrass, Miscanthus, maize (grain and grain plus stover removal), and low-input big bluestem including the assessment of: a) the quantity and quality (chemical composition) of feedstocks; b) the crop-specific nutrient use efficiency including uptake and physiological efficiency, and c) the crop-specific water balance.
Project Methods
The Water Quality Field Station (WQFS) facility includes forty-eight treatment plots (10.8 x 48 m), constructed in a randomized complete-block design, with 12 treatment plots randomly assigned within each of the four blocks or replicates. In spring 2007, several treatments were converted to biofuel production systems such that WQFS treatments include the following: 1. Big bluestem: a facsimile for the native prairie community receiving no exogenous inputs (continuing: residue removal instead of burning initiated fall 2007); 2. Maize grown in rotation with soybean and fertilized according to current university recommendations (continuing) 3. Continuous maize fertilized according to current university recommendations with no residue removal (continuing); 4. Continuous maize fertilized according to current university recommendations with residue removal at harvest (residue removal initiated fall 2007 and conversion to no-till planting spring 2008); 5. Miscanthus production using best known management practices for establishment and maintenance; 6. Switchgrass production using best known management practices for establishment and maintenance (planted May 2007 with complete stand establishment by Sept. 2007). 7. High-yielding, dual-purpose sorghum hybrid (PU8168X) with low lignin and high sugar concentrations in vegetative tissue; fertilized according to university recommendations and with residue removal. Trts. 1, 4, 5, 6 and 7 represent candidate biofuel systems, while Trts. 2, 3, and 4 are traditional food/feed systems that can also provide maize grain and soybean seed for ethanol and biodiesel, respectively. Several calculations will permit us to compare the production efficiencies of these biomass cropping systems in the context of the water, N, and C economies, the contrasting composition of the biomass per se, and the mass losses of C and N to water and the atmosphere. Various multivariate statistical approaches will then be applied to measured and calculated parameters to determine significant differences among candidate biofuel systems. Daily mass of dissolved organic carbon, NO3-N and NH4-N losses in drainage water will be calculated as the product of the 24 hr drainage volume and flow-proportional concentration of each analyte. Chamber gas flux measurements will be converted to daily gas flux estimates using accepted estimation algorithms that account for soil temperature at the time of measurement. Global warming potential (GWP-C) will be calculated by adding/subtracting the total seasonal emissions of CO2-C, CH4-C GWP equivalents and N2O-N GWP equivalents. When drainage occurs, drain flow volume and nutrient concentration in drainage water will be monitored on a daily basis. Tissues will be sampled for laboratory analyses as described above. Soil will be removed from roots and rhizomes and all tissues will be packed on dry ice, freeze-dried, ground to pass a 1-mm screen, and stored at -20oC for analysis. Biomass samples will be analyzed for cellulose, hemicellulose, and lignin using the gravimetric fiber analysis procedures.

Progress 10/01/08 to 09/30/13

Outputs
Target Audience: Federal agency personnel interested in biomass production efficiency (e.g., NIFA, ARS, DOE). Federal and state agency personnel interested in the impacts of biomass production on the environment and ecosystem services (e.g., NRCS, IN Dept. of Environmental Management, USGS, USDA-NIFA and ARS. Farmers interested in growing biomass as an economic product. Cooperative Extension personnel who advise farmers on biomass production techniques and strategies. Crop consultants who advise farmers. Private sector business people who are considering entering the biomass/biofuel marketplace. Changes/Problems: There were no major changes in approach during the course of these studies. What opportunities for training and professional development has the project provided? Numerous individuals were educated or trained during this projects lifetime. Estimates include (partial FTE combined here): Graduate students-4 Postdoctoral research associates-2 Technical and service staff-2 Undergraduate student-10 High school interns-5 Faculty professional development-6 How have the results been disseminated to communities of interest? Yes. Through the following outlets: Extension education meetings Classroom teaching Professional society meetings including the American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, Ecological Society of America. Printed popular press articles What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Biomass systems differ markedly in productivity. The most noteworthy findings include: Maize production (control system-conventional practice) is very good on soils to which this species is adapted. However, maize production on marginal soils is reduced by one-half or more (even to 0 kg/ha in 2012). Native prairie (control-no input) biomass yields with no fertilization are about 10% that of maize. Modest fertilization (50 kg N/ha) of switchgrass can result in good biomass yield (8,000 to 14,000 kg/ha), but this species is not well-adapted to soils that remain wet in spring. Miscanthus has very high biomass yield (15,000 to 30,000 kg/ha) with modest N, and is well-adapted to wet sites. Sweet and photoperiod sensitive sorghums also had consistently high biomass yields on marginal lands with modest (67 kg N/ha) N fertilization suggesting a higher N use efficincy in this system. Biomass composition of species differed with high cell wall (especially cellulose and lignin) concentrations in Miscanthus. Sorghum and maize had lower cell wall concentrations, and these were offset with higher concentrations of starch, and in the case of sweet sorghum, soluble sugars. All systems fertilized with N emitted nitrous oxide during the weeks following N fertilization. Emission was generally higher and longer lasting in maize than the other systems. Conversion of maize-soybean grain production systems to perennial biomass production reduced nitrate movement to surface waters within a year in switchgrass, but it took two years for this reduction to occur in plots transitioned to Miscanthus. Once established these N-fertilized perennial biomass systems lost the same amount of nitrate to surface waters (very low) as did the 25 year old native prairie that was unfertilized. Practices for establishing and managing these biomass systems for high producitivity, while minimizing environmental impacts are better understood as a result of these studies.

Publications

  • Type: Journal Articles Status: Published Year Published: 2013 Citation: Woodson, P, J.J. Volenec, and S.M. Brouder. 2013. Field-scale potassium and phosphorus fluxes in the bioenergy crop switchgrass: Theoretical energy yields and management implications. J. Plant Nutr. Soil Sci. 176:387-399.
  • Type: Journal Articles Status: Submitted Year Published: 2013 Citation: Chivenge, P., R.F. Turco, J.J. Volenec, and S.M.Brouder. 2013. A meta-analysis of soil organic carbon sequestration under biofuel cropping systems.
  • Type: Journal Articles Status: Submitted Year Published: 2013 Citation: Sajeev E.M., B.M. Gramig, W.E. Tyner, S.M. Brouder, J.J. Volenec, and D.R. Smith. 2013. Modeling yield and N20 flux to assess sustainability of six bioenergy cropping systems.
  • Type: Journal Articles Status: Submitted Year Published: 2013 Citation: Trybula, E., J.L. Burks, C. Raj, I. Chaubey, S.M. Brouder, and J.J. Volenec. 2013. Parameterization of perennial bioenergy feedstock grasses in the SWAT model: using field-scale data to improve watershed-scale analysis.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Trybula, E., I. Chaubey, J. Frankenberger, S.M. Brouder, and J.J. Volenec. 2012. Quantifying Ecohydrologic Impacts of perennial rhizomatous grasses on tile discharge, a plot level comparison of continuous corn, mixed prairie, upland switchgrass, and Miscanthus x giganteus. Abstract 297-9. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Oct. 21-24. Cincinnati OH. http://scisoc.confex.com/scisoc/2012am/webprogram/Paper75175.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Long, M., J.J. Volenec, and S. M. Brouder. 2012. Nitrogen impacts on the yield and cell wall composition of contrasting sorghum lines used for biomass. Abstract 383-8. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Oct. 21-24. Cincinnati OH. http://scisoc.confex.com/scisoc/2012am/webprogram/Paper75148.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Dierking, R., J.J. Volenec, and S.M. Brouder. 2012. The potential of maize and sorghum biomass grown on marginal sites. Abstract 247-5. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Oct. 21-24. Cincinnati OH. http://scisoc.confex.com/scisoc/2012am/webprogram/Paper72548.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Burks, J., S.M. Brouder, and J.J. Volenec. 2012. Seasonal accumulation and partitioning of carbon- and nitrogen-containing compounds in perennial bioenergy crops. Abstract 99-4. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Oct. 21-24. Cincinnati OH. http://scisoc.confex.com/scisoc/2012am/webprogram/Paper72902.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2012 Citation: Moore, K.,S.J. Birrell, R.C. Brown, M. Casler, J.E. Euken, D.J. Hayes, M. Hanna, J.D. Hill, C.L. Kling, K.L. Jacobs, D.A. Laird, R. Mitchell, P.T. Murphy, R. Raman, C.V. Schwab, K.J. Shinners, K.P. Vogel, and J.J. Volenec. 2012. Sustainable production and distribution of bioenergy for the Central USA: An agro-ecosystem approach to sustainable biofuels production via the pyrolysis-biochar platform (USDA-NIFA AFRI CAP, Project #2010-05073). Abstract 26-3. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Oct. 21-24. Cincinnati OH. http://scisoc.confex.com/scisoc/2012am/webprogram/Paper74539.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Dierking, R.M., J.J. Volenec, and P.T. Murphy. 2013. Forage yield and quality of Miscanthus giganteus subjected to simulated haying/grazing conditions. Abstract 245-5. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Nov. 2-6, Tampa, FL. https://scisoc.confex.com/crops/2013am/webprogram/Paper79122.html
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Long, M.K., J.J. Volenec, and S.M. Brouder. 2013. Theoretical ethanol yield for potential bioenergy sorghum genotypes of differing compositions. Abstract 373-9. Inter. Meeting of the Amer. Soc. Agron.-Crop Sci. Soc. of Amer.-Soil Sci. Soc. of Amer. Nov. 2-6, Tampa, FL. https://scisoc.confex.com/crops/2013am/webprogram/Paper80060.html


Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: The long-term goals of this project is to determine the agronomic performance and environmental impacts of growing bioenergy crops. The following studies are underway at the end of September 2012. The Water Quality Field Station experiment includes Shawnee switchgrass (planted 2007), Miscanthus x g. (planted 2008), a big bluestem-dominated prairie (planted 1992), maize grown for stover and grain (planted annually), and a biomass sorghum (planted annually). Biomass yield and greenhouse gas emissions are measured on all plots, and belowground biomass is also being measured on the perennial biomass species. Several experiments are underway at the Throckmorton Purdue Agricultural Center (TPAC) including: the impact of N, P, and K on switchgrass and Miscanthus x g yield and biomass composition; a comparative analysis of agronomic performance and water infiltration/soil erosion of switchgrass, willow, poplar, Miscanthus x g, and maize grown for grain and stover; N use efficiency of maize versus sorghum lines (sweet, grain, photoperiod-sensitive); and a comparative productivity study of a new biomass switchgrass, a big bluestem/indiangrass prairie, and Miscanthus x g.. The latter two trials at TPAC are being replicated (starting in 2011) at the Northeast Purdue Agricultural Center and the Southeast Purdue Agricultural Center on soils considered marginal for profitable and environmentally sound maize and soybean production. Biomass samples from all studies are being analyzed for C, N, sugar and starch, cellulose, hemicellulose, lignin, and ash. Data from all sites are being analyzed. Information is being disseminated as talks and posters at professional meetings, as peer-reviewed scientific publications, and as invited presentations at academic institutions and Federal agencies. PARTICIPANTS: In addition to project PIs the following individuals participated in this research: Ryan Dierking, Jennifer L. Burks, Suzanne Cunningham, Niki DeArmond, Ron Turco, Mary Jane Orr TARGET AUDIENCES: Research audiences interested in biomass research; Extension staff and faculty needing knowledge to share with agricultural professionals interested in growing biomass, university faculty teaching courses related to biomass production and the environment, general public who are interested in bioenergy research. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
At the Water Quality Field Station experiment with perennial biomass species Miscanthus x g accumulated more biomass (16 to 38 Mg ha-1) than switchgrass (9 to 13 Mg ha-1) and prairie (3 to 6 Mg ha-1), while producing the least belowground biomass. Of the belowground biomass components, Miscanthus had lower root mass than switchgrass and prairie. Averaged across the study, mean aboveground biomass, stem base, and rhizome C concentrations were highest in Miscanthus while root C concentrations were highest in switchgrass. These results suggest these perennial grasses differ in both biomass yield and inter-organ dry matter partitioning that may impact long-term persistence and production/partitioning as well as C partitioning, directly affecting yield potentials. At the Throckmorton Purdue Agricultural Center the switchgrass P and K nutrition study revealed that, although low P and K reduced yield of both alfalfa and maize that preceded switchgrass, switchgrass biomass was high irrespective of very low soil test P (4 mg kg-1) and K (<70 mg kg-1) levels. Linear-plateau regression models effectively described the relationship of soil test P and K to tissue P and K concentrations, and tissue P and K concentrations accurately predict removal of P and K in harvest biomass. However, neither soil test P and K, nor tissue P and K concentrations were effective as diagnostics for predicting switchgrass biomass yield nor could soil tests and their change with cropping predict nutrient removal. Concentrations of cellulose, hemicellulose, lignin and ash were not influenced by P and K nutrition. Predicted bio-ethanol production was closely associated with biomass yield whereas high biomass K concentrations reduced estimated bio-oil production per hectare by as much as 50%. Additional research on P and K nutrition of switchgrass is needed to identify diagnostics and managements to meet the bioenergy production co-objectives of having high yield of biomass with very low mineral nutrient concentrations (especially K) while sustaining and enhancing marginal soils. The N use studies with maize and sorghum revealed a significant species x location interaction. Maize had a total biomass yield ranging from 548 to 10,768 kg ha-1, while sweet sorghum consistently had the highest biomass ranging from 8,750 to 16,753 kg ha-1. The biomass cellulose concentration was also different across locations and species with maize having the lowest cellulose concentrations (160 to 280 g kg-1), while photoperiod-sensitive sorghum (PPS) had the highest (250 to 350 g kg-1). Predicted conversion of both cellulose and hemicellulose into ethanol differed significantly with species and location with maize ethanol production potential ranging from 102 to 1228 L ha-1, while PPS had the greatest predicted ethanol production (1368 to 2333 L ha-1). Our initial results suggest sorghum has the potential to produce more ethanol on these marginal soils when compared to maize.

Publications

  • No publications reported this period


Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: The impact of biomass cropping system on soil C and N dynamics continue to be assessed. Research is characterizing microbial activity, shifts in microbial community structure, nutrient-utilization potential, and soil carbon and nitrogen status. In addition, biomass yields of perennial biomass systems were compared and herbage composition measured. Root and rhizome masses/depths and composition were assessed. Additional sites were established to assess productivity and soil and water impacts of cultivating woody and herbaceous energy crops on marginal croplands. Monitoring of water runoff quantity and quality and measurement of soil quality and plant growth at this site was commenced. PARTICIPANTS: In addition to project PIs the following individuals participated in this research: Ryan Dierking, Jennifer L. Burks, Suzanne Cunningham, Niki DeArmond, Ron Turco, Mary Jane Orr, K. Vester, Indrajeet Chaubey. TARGET AUDIENCES: Research audiences interested in biomass research; Extension staff and faculty needing knowledge to share with agricultural professionals interested in growing biomass, University faculty teaching courses related to biomass production and the environment, General public who are interested in bioenergy research. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The no-till maize with residue removal biomass system tends to reduce soil respiration rates, whereas the native prairie control plot and in some years, Miscanthus, have elevated soil respiration rates. Based on fatty acid methyl ester analysis, soil microbial populations of the native prairie, and in some years the continuous maize with residue removal, differ from the other biomass cropping systems. Bacterial ammonia monooxgenase genes were largely absent from the native prairie control soils suggesting an impaired ability to nitrify N compared to the other biomass cropping systems. The native prairie, Miscanthus, switchgrass and sorghum biomass plots demonstrate a higher diversity of nitrogenase genes in comparison to maize production systems. Yields for all three perennial biomass crops peaked in August with Miscanthus producing significantly more biomass than switchgrass and native prairie. Prairie yields were similar in 2009 and 2010, while switchgrass and Miscanthus yields increased from 2009 to 2010, reflecting greater plant establishment with stand age. Miscanthus produced significantly fewer roots and rhizomes than both switchgrass and prairie. Both amino N and protein concentrations within rhizomes decreased during the growing season and accumulated in the fall. Miscanthus rhizomes had significantly more amino N and protein than both switchgrass and prairie. Sugar and starch concentrations within rhizomes decreased in spring. Starch concentrations increased in May/June, while sugar concentrations increased in Sept. Rhizomes from the native prairie had lower sugar and starch concentrations than switchgrass and Miscanthus. Both amino N and protein concentrations of roots decreased during the growing season and accumulated in the fall. Root sugar and starch concentrations decreased in spring. Starch concentrations accumulated by June, and while sugar concentrations increased in Sept. Miscanthus roots had lower concentrations for both sugar and starch than switchgrass and prairie.

Publications

  • Feng, Q., I. Chaubey, J. Volenec, M.M. Kalcic, Y. Gu Her, M.A. Thomas, and C. Raj. 2011. Identification of available marginal land for biofeedstock production in Wildcat Creek watershed. Poster presented at the 6th Frontiers in Bioenergy Conference; US-Brazil Symposium on Sustainable Bioenergy. May 16-18, 2011, West Lafayette, IN.
  • Vester, K., P. Murphy, and I Chaubey. 2011. Production of herbaceous and woody biomass feedstocks on marginal cropland. 6th Annual Frontiers in Bioenergy Conference; US-Brazil Symposium on Sustainable Bioenergy. May 16-18, 2011, West Lafayette, IN.


Progress 10/01/09 to 09/30/10

Outputs
OUTPUTS: Our objective was to quantify seasonal N accumulation and partitioning among organs of Miscanthus x. giganteus, switchgrass (Panicum virgatum), and a big bluestem (Andropogon gerardii)-dominated prairie. Miscanthus and switchgrass plots received 56 kg ha-1 yr-1 of N while the prairie plots were unfertilized. Plants were sampled six times during the growing season and once in December. Plants were divided into roots, rhizomes, stem bases, and above-ground herbage, and were analyzed for yield and composition. In 2009 yield of the 2-yr-old Miscanthus stand in August (16.03 t ha-1) was greater than that of the 3-yr-old switchgrass stand (8.96 t ha-1) and the 28-yr-old prairie (3.47 t ha-1). While Miscanthus produced the most above-ground growth, it produced the least amount of total below-ground tissue in August, yielding 2.93 kg m-3 compared to the prairie (9.6 kg m-3) and the switchgrass (6.8 kg m-3). These below-ground tissues of switchgrass and Miscanthus had similar sugar (128 & 127 mg g-1 dry wt.) and starch (335 & 320 mg g-1 dry wt.) concentrations. Below-ground prairie tissues contained 123 mg g-1 dry wt. sugar, but had low starch concentrations (185 mg g-1 dry wt.). Data from 2010 will be reported. Quantities and above-/below-ground allocation patterns of total C, starches, and sugars suggest a comparative advantage for Miscanthus as a bioenergy crop. However, more research is needed to understand spatio-temporal production aspects including stand age and soil fertility. PARTICIPANTS: J.J. Volenec, co-PI s.M. Brouder, co-PI R.F. Turco, faculty J.L. Burks, Ph.D. candidate S.M. Cunningham, technician N. De Armond, technician TARGET AUDIENCES: Farmers Agricultural input providers Federal agencies such as EPA, NRCS, USDA Corporations involved in energy R&D like Exxon, BP Public interested in energy independence PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The current dearth of data and knowledge comparing potential biomass production systems prevents informed choices from being made. From a farmer perspective, annual grain systems have numerous desirable attributes for biomass production when compared to second generation, perennial crops such as switchgrass and Miscanthus. Equipment and management are familiar, revenues accrue in the first year of production and the system maximizes both potential market diversity (grain, silage, stover, biomass, etc.) and year-to-year flexibility in land use. Likewise, from an industrial perspective, annual sources will be important to synchronize feedstock availability with capacity at conversion facilities. Yet, both species and managements of common annual systems have been designed and optimized for production of food and feed while for candidate perennial bioenergy crops the systems remain poorly characterized. Switching to a fuel-production focus requires reassessment of optimization and efficiency metrics. With energy as a predominant input in intensive management, net energy balance must be positive but such an accounting entirely overlooks major resources that currently have no energy equivalency value. The purpose of this presentation is to review the current status of resource accounting in biomass feedstocks. Certainly, known biophysical limits to nutrient (especially N), water and radiation use efficiency have and will continue to constrain primary productivity. Over the past 70+ years, yields of widely grown commodities such as maize have increased dramatically due to a combination of genetic improvement and management intensification realized against increasing atmospheric CO2 concentrations but the extent to which these yield increases are the product of increased system efficiencies is the subject of ongoing debate. Regardless, a bioenergy context for annual crop performance requires a higher standard for all efficiencies and an unprecedented exactness in resource accounting. Concomitantly, novel valuation systems with equivalencies for multiple ecosystem services must be developed (e.g. air versus water quality) and used to guide decision makers. This presentation will focus on efficiency interactions and tensions in past/current cropping systems and discuss potential and key limitations for efficiency improvements via management and/or crop improvement.

Publications

  • Burks, J., J.J. Volenec, and S.M. Brouder. 2010. Nutrient cycling dynamics in perennial bioenergy crops. pp. 24. In: Proc. China-US 2010 Joint Symp. on Energy, Ecosystem, and Environmental Change. Beijing, China. September 22-24.
  • Brouder, S.M., and J.J. Volenec. 2010. Greenhouse gas emissions and pelicans: Ecological accounting in bioenergy cropping systems. pp. 27-29. In: Proc. China-US 2010 Joint Symp. on Energy, Ecosystem, and Environmental Change. Beijing, China. September 22-24.
  • Volenec, J.J., S.M. Brouder, and R.F. Turco. 2010. Agroecological considerations when growing biomass. pp. 39-40. In: Proc. China-US 2010 Joint Symp. on Energy, Ecosystem, and Environmental Change. Beijing, China. September 22-24.
  • Volenec, J.J., S.M. Brouder, R.F. Turco, G. Ejeta, and D. Smith. 2010. Impact of water and nitrogen on biomass production and ecosystem services. pp. 18. In: Proc. Frontiers in Bioenergy, Purdue University, May 24-25.
  • Burks, J, J.J. Volenec, and S.M. Brouder. 2010. N cycling dynamics in perennial bioenergy crops. ASA-CSSA-SSSA International Meetings, Oct. 31 to Nov. 4, 2010. Poster No. 56-14 N. http://a-c-s.confex.com/crops/2010am/webprogram/Paper59353.html.
  • Pembleton, K.G., D.J. Donaghy, J.J. Volenec, R.S. Smith, and R.P. Rawnsley. 2010. Yield, yield components and shoot morphology of four contrasting lucerne (Medicago sativa) cultivars grown in three cool temperate environments. Crop Pasture Sci. 61:503-511.
  • Brouder, S.M., R.F. Turco, and J.J. Volenec. 2010. Nitrogen use efficiency in bioenergy cropping systems. pp. 27-29. In: Proc. 2nd China-US Workshop on Biotechnology of Bioenergy Plants. Beijing, China. September 19-21.
  • Lissbrant, S., S. Stratton, S.M. Cunningham, S.M. Brouder, and J.J. Volenec. 2009. Impact of long-term phosphorus and potassium fertilization on alfalfa forage quality-yield relationships. Crop Sci. 49:1116-1124.
  • Pembleton K.G., R.P. Rawnsley, D.J. Donaghy, and J.J. Volenec. 2009. Water deficit alters canopy structure but not photosynthesis during the regrowth of alfalfa (Medicago sativa L.). Crop Sci. 49:722-731.
  • Lissbrant, S., S.M. Brouder, S.M. Cunningham, and J.J. Volenec. 2010. Identification of fertility regimes that enhance long-term productivity of alfalfa using cluster analysis. Agron. J. 102:580-591.
  • Ventroni, L.M., J.J. Volenec, and C.C. Cangiano. 2010. Fall dormancy and cutting frequency impact on alfalfa yield and yield components. Field Crops Res. 119:252-259.
  • Brouder, S.M., and J.J. Volenec. 2010. Environmental impacts of using annual crops for biofuel. ASA-CSSA-SSSA International Meetings, Oct. 31 to Nov. 4, 2010. Presentation No. 250-1. http://a-c-s.confex.com/crops/2010am/webprogram/Paper57723.html.
  • Brouder, S.M., and J.J. Volenec. 2010. Grain and dual purpose production: system efficiencies, limitations, and potential. ASA-CSSA-SSSA International Meetings, Oct. 31 to Nov. 4, 2010. Presentation No. 124-2. http://a-c-s.confex.com/crops/ 2010am/webprogram/Paper58277.html.
  • Volenec, J.J. and S.M. Brouder. 2010. Water-use efficiency in biomass cropping systems. pp. 18-19. In: Proc. 2nd China-US Workshop on Biotechnology of Bioenergy Plants. Beijing, China. September 19-21.


Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: Our overall goal is to develop a cropping system-level analysis of the potential for Miscanthus, switchgrass, maize-based and low-input native prairie production systems to provide renewable fuel while protecting natural resources. Our hypothesis is that candidate biofuel cropping systems differ in total yield and yield of structural and non-structural carbohydrate pools that determine profitability, but that candidate systems also differ in water, N, and C economies; these differences will drive changes in soil, water and air quality that, in turn, determine the scope and nature of environmental impacts and sustainability. Several activities have occurred or are in process with this goal in mind including studies at Purdue University's Water Quality Field Station where we are analyzing the C, N, and water economies of several biomass species. One graduate research assistant is comparing the N cycling in perennial grasses. A second graduate research assistant is determining the impact of biomass cropping system on soil C and N dynamics including detailed analysis of soil microbiological processes. Our research team has been invited to participated in numerous conferences to discuss findings from our research including: International Plant Nutrition Colloquium (Sacramento CA); Energy-Climate Change Nexus (Oak Ridge National Laboratory); Sun Grant Biomass Meeting (Ames, IA); Petroleum Environment Research Forum (Philadelphia PA); and the University of Illinois Biomass Conference (Urbana IL). Collaborations have been formalized with the International Plant Nutrition Institute and Mendel Biotechnology. Funds have been leveraged by obtaining additional support from the USDA National Needs Fellowship program and the USDA Long-term Agroecology Program-Sustainable Agricultural Systems program. A new website has been created to disseminate information. We consulted with the Government Accounting Office in their effort to understand the impact of bioenergy production on the environment. PARTICIPANTS: J.J. Volenec, P.I. S.M. Brouder, P.I. R.F. Turco, co-P.I. D. Smith (USDA-ARS), co-P.I. G. Ejeta, co-P.I. S.M. Cunningham, Technical N. DeArmond, Technical Jennifer Burks, Graduate Research Assistant Mary-Jane Orr, Graduate Research Assistant Damian Allen (Mendel Biotechnology), Collaborator Erik Sack (Mendel Biotechnology), Collaborator T. Scott Murrell (International Plant Nutrition Institute), Collaborator TARGET AUDIENCES: Scientists through scientific meetings. Policy makers through meetings, conferences, and formal visits. Educators through meetings and discussions. Industry groups through meetings and collaborations. Students through mentoring and experiential learning activities. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Through our efforts there is heightened awareness of the tension between production of biomass and the environment. One clear example is the recently released GAO Report that highlights water use in biomass production (http://www.gao.gov/new.items/d10116.pdf). In addition, the interaction between C and N in determining system productivity and edge-of-field losses of N and C to water and as greenhouse gases.While changes in actions awaits a more complete analysis of data from our studies (and others underway world-wide) it is clear that systems-level thinking is absolutely necessary to make choices that benefit the public while foster ecosystem services.

Publications

  • Brouder, S.M. and J.J. Volenec. 2008. Impact of climate change on crop nutrient and water use efficiencies. Physiol. Plant. 133:705-724.
  • Brouder, S.M., R.F. Turco, and J.J. Volenec. 2008. Environmental consequences of biofuel feedstock production: soil, water, and air quality. Presentation 545-2. ASA-CSSA-SSSA International Meetings, Oct. 5 to 9, 2008. Houston, TX. http://a-c-s.confex.com/crops/2008am/webprogram/Paper45598.html.


Progress 10/01/07 to 09/30/08

Outputs
OUTPUTS: Plots of switchgrass, sorghum, and Miscanthus were established at the water quality field station (WQFS). A second year is required before we can obtain relevant yield data for Miscanthus. Yield and composition of the switchgrass and sorghum will be compared to several maize cropping systems. A comparative analysis of net energy balance and off-site losses of nitrogen and carbon, and water use efficiencies is underway. PARTICIPANTS: S.M. Brouder J.J. Volenec R.F. Turco G. Ejeta D. Smith USDA-ARS, National Soil Erosion Research Laboratory, West Lafayette IN S.M. Cunningham TARGET AUDIENCES: Consumers interested in liquid fuels. Environmentalists interested on the impact of biomass production on water and air quality, and on climate change. Farmers interested in growing biomass crops. People interested in wildlife production and conservation. Departments of Energy at the State and Federal levels. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This project is a few months old. Outcomes are awaiting analysis of data and its interpretation. However, the approach we are using has generated intense interest nationwide. We are being invited to numerous conferences where the impact of biomass production on the environment is a focus.

Publications

  • Brouder, S.M., and J.J. Volenec. 2007. Impact of climate change on crop nutrient and water use efficiencies. In Proc. 609 of the Intern. Fertilizer Soc., December 2007, York, UK. 32 pp. ISBN Number 978-0-85310-246-5.
  • Brouder, S.M. and J.J. Volenec. 2008. Impact of climate change on crop nutrient and water use efficiencies. Physiol. Plant. 133:705-724.