Bioenergy Crops and Carbon Sequestration

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

[1]  M. van Noordwijk,et al.  Agricultural options for mitigation of greenhouse gas emissions , 1996 .

[2]  J. Oades,et al.  The retention of organic matter in soils , 1988 .

[3]  Gregg Marland,et al.  Forests for Carbon Sequestration or Fossil Fuel Substitution? A Sensitivity Analysis , 1997 .

[4]  S. B. McLaughlin,et al.  Evaluating physical, chemical, and energetic properties of perennial grasses as biofuels , 1996 .

[5]  R. Lal,et al.  Soil carbon dynamics in cropland and rangeland. , 2002, Environmental pollution.

[6]  Robert D. Perlack,et al.  Emissions of C02 from energy crop production , 1991 .

[7]  D. Hall,et al.  Biomass energy development and carbon dioxide mitigation options , 1995 .

[8]  Y. Hsieh,et al.  Uncertainties and novel prospects in the study of the soil carbon dynamics. , 2002, Chemosphere.

[9]  A. Franzluebbers,et al.  Bermudagrass Management in the Southern Piedmont USA: VII. Soil-Profile Organic Carbon and Total Nitrogen , 2005 .

[10]  R. Lal,et al.  Alternatives to Slash and Burn Agriculture , 1993 .

[11]  C. Cambardella,et al.  Carbon Dynamics of Surface Residue– and Root‐derived Organic Matter under Simulated No‐till , 2000 .

[12]  M. Cannell,et al.  Carbon sequestration and biomass energy offset: theoretical, potential and achievable capacities globally, in Europe and the UK , 2003 .

[13]  K. Potter,et al.  Carbon storage after long-term grass establishment on degraded soils , 1999 .

[14]  J. Shaffer,et al.  Evaluation of soil organic carbon under forests, cool-season and warm-season grasses in the northeastern US , 1999 .

[15]  W. Dugas,et al.  Soil CO2 flux in a tallgrass prairie , 2000 .

[16]  Tristan R. Brown,et al.  Biorenewable Resources: Engineering New Products from Agriculture , 2003 .

[17]  C. W. Wood,et al.  Impacts of soil management on root characteristics of switchgrass , 2000 .

[18]  Bruce A. McCarl,et al.  Soil Carbon: Policy and Economics , 2001 .

[19]  M. Wander,et al.  Tillage effects on soil organic carbon distribution and storage in a silt loam soil in Illinois , 1999 .

[20]  Gregg Marland,et al.  Should we store carbon in trees? , 1992 .

[21]  Stan D. Wullschleger,et al.  Soil carbon dynamics beneath switchgrass as indicated by stable isotope analysis. , 2000 .

[22]  S. Schiavon,et al.  Climate Change 2007: Impacts, Adaptation and Vulnerability. , 2007 .

[23]  D. F. Grigal,et al.  Soil carbon changes associated with short-rotation systems , 1998 .

[24]  L. R. Oldeman.  The Global Extent of Soil Degradation , 1992 .

[25]  G. Buyanovsky,et al.  Comparative Analyses of Carbon Dynamics in Native and Cultivated Ecosystems. , 1987, Ecology.

[26]  S. B. McLaughlin,et al.  A review of carbon and nitrogen balances in switchgrass grown for energy , 1998 .

[27]  E. Gregorich,et al.  Retention and Turnover of Corn Residue Carbon in Some Eastern Canadian Soils , 1998 .

[28]  C. Rice,et al.  Carbon and Nitrogen Pools in a Tallgrass Prairie Soil under Elevated Carbon Dioxide , 2004 .

[29]  Eric A. Davidson,et al.  Changes in soil carbon inventories following cultivation of previously untilled soils , 1993 .

[30]  Timothy B. Parkin,et al.  Defining and Assessing Soil Quality , 1994 .

[31]  L. Mann,et al.  CHANGES IN SOIL CARBON STORAGE AFTER CULTIVATION , 1986 .

[32]  Ralph P. Overend,et al.  Making a business from biomass in energy, environment, chemicals, fibers, and materials : proceedings of the 3rd Biomass Conference of the Americas, Montréal, Québec, Canada, August 24-29, 1997 , 1997 .

[33]  David C. Ditsch,et al.  A review of soil erosion potential associated with biomass crops , 1998 .

[34]  S. B. McLaughlin,et al.  Evaluating environmental consequences of producing herbaceous crops for bioenergy. , 1995 .

[35]  J. Oades,et al.  Decomposition of plant material in Australian soils. III. Residual organic and microbial biomass C and N from isotope-labelled legume material and soil organic matter, decomposing under field conditions , 1985 .

[36]  Keith Paustian,et al.  Potential soil carbon sequestration in overgrazed grassland ecosystems , 2002 .

[37]  Wayne H. Smith,et al.  Biomass Energy Development , 1986 .

[38]  W. M. Post,et al.  Soil carbon sequestration and land‐use change: processes and potential , 2000 .

[39]  E. Carter,et al.  Enhancing the soil organic matter pool through biomass incorporation , 2003 .

[40]  R. Weil,et al.  Crop Cover Root Channels May Alleviate Soil Compaction Effects on Soybean Crop , 2004 .

[41]  V. R. Tolbert,et al.  Changes in soil quality and below-ground carbon storage with conversion of traditional agricultural crop lands to bioenergy crop production. , 2002, Environmental pollution.

[42]  J Johansson,et al.  Estimating Swedish biomass energy supply , 1999 .

[43]  J. Hassink,et al.  The capacity of soils to preserve organic C and N by their association with clay and silt particles , 1997, Plant and Soil.

[44]  Henry Kelly,et al.  Renewable Fuels and Electricity for a Growing World Economy: Defining and Achieving the Potential , 1993 .

[45]  T. O. Barnwell,et al.  Modeling soil carbon and agricultural practices in the central U.S.: an update of preliminary study results. , 1998 .

[46]  David S. G. Thomas,et al.  World atlas of desertification. , 1994 .

[47]  V. Garg.  Interaction of tree crops with a sodic soil environment: potential for rehabilitation of degraded environments , 1998 .

[48]  J. Herrick,et al.  Soil carbon dynamics and potential carbon sequestration by rangelands. , 2002, Environmental pollution.

[49]  R. B. Jackson,et al.  Decomposition of plant material in Australian soils. II. Residual organic 14C and 15N from legume plant parts decomposing under field and laboratory conditions , 1984 .

[50]  J. Ranney,et al.  Carbon storage and recycling in short-rotation energy crops , 1991 .

[51]  J. Melillo,et al.  Stocks and dynamics of soil carbon following deforestation for pasture in Rondônia. , 1998 .

[52]  Dale W. Johnson.  Effects of forest management on soil carbon storage , 1992 .

[53]  Tanja Hueber,et al.  A change of climate. , 1998, Nursing standard (Royal College of Nursing (Great Britain) : 1987).

[54]  B. Cook,et al.  Dissolved organic carbon in old field soils : total amounts as a measure of available resources for soil mineralization , 1992 .

[55]  G. Tuskan.  Short-rotation woody crop supply systems in the United States: what do we know and what do we need to know? , 1998 .

[56]  Changsheng Li,et al.  Modeling carbon biogeochemistry in agricultural soils , 1994 .

[57]  Rattan Lal,et al.  Global Potential of Soil Carbon Sequestration to Mitigate the Greenhouse Effect , 2003 .

[58]  K. A. Stewart,et al.  Switchgrass biomass and chemical composition for biofuel in Eastern Canada. , 1999 .

[59]  D. F. Grigal,et al.  Carbon and nitrogen cycling during old-field succession: Constraints on plant and microbial biomass , 1990 .

[60]  S. Saggar,et al.  Particle Size Fractions and Their Use in Studies of Soil Organic Matter: I. The Nature and Distribution of Forms of Carbon, Nitrogen, and Sulfur1 , 1981 .

[61]  R. Lemus.  Switchgrass as an Energy Crop: Fertilization, Cultivar, and Cutting Management , 2004 .

[62]  E. Hansen.  Soil carbon sequestration beneath hybrid poplar plantations in the North Central United States , 1993 .

[63]  C. W. Wood,et al.  Impact of row spacing, nitrogen rate, and time on carbon partitioning of switchgrass , 2001 .

[64]  John J. A. Ingram,et al.  Managing carbon sequestration in soils: concepts and terminology , 2001 .

[65]  Ronald F. Follett,et al.  Assessing soil carbon sequestration in turfgrass systems using long-term soil testing data , 2002 .

[66]  Martin Heller,et al.  Life cycle energy and environmental benefits of generating electricity from willow biomass , 2004 .

[67]  V. R. Tolbert,et al.  High-value renewable energy from prairie grasses. , 2002, Environmental science & technology.

[68]  Gregg Marland,et al.  Carbon management and biodiversity. , 2003, Journal of Environmental Management.

[69]  J. Pretty,et al.  Agricultural Influences on Carbon Emissions and Sequestration: A Review of Evidence and the Emerging Trading Options , 2001 .

[70]  C. W. Wood,et al.  Soil management impacts on soil carbon sequestration by switchgrass , 2000 .

[71]  H. Mantel.  A Change of Climate , 1994 .

[72]  Rolf Sommer,et al.  Carbon storage and root penetration in deep soils under small-farmer land-use systems in the Eastern Amazon region, Brazil , 2000, Plant and Soil.

[73]  Ronald F. Follett,et al.  Soil management concepts and carbon sequestration in cropland soils , 2001 .

[74]  J. Reeder,et al.  Soil C and N changes on conservation reserve program lands in the Central Great Plains , 1998 .

[75]  K. Paustian,et al.  GRASSLAND MANAGEMENT AND CONVERSION INTO GRASSLAND: EFFECTS ON SOIL CARBON , 2001 .

[76]  K. R. Mankin,et al.  Quantifying Changes in Soil Physical Properties from Soil and Crop Management: A Survey of Experts , 1996 .

[77]  J. Palutikof,et al.  Climate change 2007 : impacts, adaptation and vulnerability , 2001 .

[78]  Roberto C. Izaurralde,et al.  Management effects on soil C storage on the Canadian prairies , 1998 .

[79]  C. Rice,et al.  Carbon dynamics and microbial activity in tallgrass prairie exposed to elevated CO2 for 8 years , 2000, Plant and Soil.

[80]  C. Campbell,et al.  Crop rotation and tillage impact on carbon sequestration in Canadian prairie soils , 2003 .

[81]  R. Lal,et al.  Carbon Sequestration , 2010 .

[82]  J. Raich,et al.  Biomass, carbon and nitrogen dynamics of multi-species riparian buffers within an agricultural watershed in Iowa, USA , 2003, Agroforestry Systems.

[83]  S. R. Wilkinson,et al.  Bermudagrass Management in the Southern Piedmont USA: I. Soil and Surface Residue Carbon and Sulfur , 2001 .

[84]  James W. Fyles,et al.  Carbon sequestration in perennial bioenergy, annual corn and uncultivated systems in southern Quebec , 2001 .

[85]  M. L. Thompson,et al.  Compositional Differences in Organic Matter among Cultivated and Uncultivated Argiudolls and Hapludalfs Derived from Loess , 1988 .

[86]  M. Harmon,et al.  Effects on Carbon Storage of Conversion of Old-Growth Forests to Young Forests , 1990, Science.

[87]  D. Pennock,et al.  Cultivation-Induced Effects on Belowground Biomass and Organic Carbon , 2002 .

[88]  Charles T. Garten,et al.  Landscape level differences in soil carbon and nitrogen: Implications for soil carbon sequestration , 2002 .

[89]  J. Blair,et al.  CHANGES IN ECOSYSTEM STRUCTURE AND FUNCTION ALONG A CHRONOSEQUENCE OF RESTORED GRASSLANDS , 2002 .

[90]  Robert L. Late.  Defining Soil Quality for a Sustainable Environment , 1995 .