University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln

Adam Liska Papers Biological Systems Engineering

2012

Energy Issues Affecting Corn/Soybean Systems: Challenges for Sustainable Production

Douglas L. Karlen USDA-ARS, Ames, Iowa, [email protected]

David Archer USDA-ARS, Mandan, ND, [email protected]

Adam Liska University of Nebraska - Lincoln, [email protected]

Seth Meyer Food and Agricultural Policy Research Institute–Missouri, Columbia, [email protected]

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Karlen, Douglas L.; Archer, David; Liska, Adam; and Meyer, Seth, "Energy Issues Affecting Corn/Soybean Systems: Challenges for Sustainable Production" (2012). Adam Liska Papers. 12. https://digitalcommons.unl.edu/bseliska/12

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Energy Issues Affecting Corn/Soybean Systems: Challenges for Sustainable Production

The corn/soybean production system models the complexities involved in the generation, supply, distribution, and use of energy. (Photo images from Shutterstock.)

bstract of systems” or even “systems within energy issue, life cycle assessment is A ecosystems” because of their complex used as a tool to evaluate the impact Quantifying energy issues associ- linkages to global food, feed, and fuel of what many characterize as a simple ated with agricultural systems, even production. production system. This approach for a two-crop corn (Zea mays L.) and Two key economic challenges at demonstrates the importance of hav- soybean (Glycine max [L.] Merr.) rota- the field and farm scale for decreas- ing accurate greenhouse gas and soil tion, is not a simple task. It becomes ing energy use are (1) overcoming organic carbon information for these even more complicated if the goal is adoption barriers that currently limit analyses to be meaningful. to include all aspects of sustainability implementation of energy-conserving Traditional and emerging mar- (i.e., economic, environmental, and production practices and (2) demon- ket and policy forces affecting energy social). This Issue Paper examines strating the viability of sustainable issues within corn/soybean systems energy issues associated with and af- bioenergy feedstock production as are examined to project the effects of fecting corn/soybean rotations by first part of a landscape management plan increasing bioenergy demand associ- defining the size of the system from focused not only on corn/soybean ated with the Energy Independence both a U.S. and global perspective and production but on all aspects of soil, and Security Act of 2007. Uncertainty then establishing boundaries based water, and air resource management. with regard to biofuel policy is a ma- on the Farm Bill definition of sustain- It is also important to look beyond di- jor factor affecting energy issues in ability. This structured approach is es- rect energy consumption to address the all aspects of agriculture. This uncer- sential to help quantify energy issues complex economics affecting energy tainty affects investments in biofuel within corn/soybean systems that are issues associated with corn/soybean production and energy demand, which themselves best described as “systems systems. To help address the complex together influence commodity prices,

This material is based upon work supported by the U.S. Department of Agriculture’s (USDA) National Institute for Food and Agriculture (NIFA) Grants No. 2010- 38902-20899, No. 2009-38902-20041, and No. 2008-38902-19327. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of USDA–NIFA. CAST Issue Paper 48 Task Force Members Adam J. Liska Authors , Department of Timothy M. Smith, Bioproduct Biological Systems Engineering, and Biosystems Engineering, Uni- University of Nebraska–Lincoln Douglas L. Karlen (Chair), USDA– versity of Minnesota–Twin Cities ARS, National Laboratory for Seth Meyer, Food and Agricultural Campus, St. Paul Agriculture and the Environment, Policy Research Institute–Missouri, Anthony F. Turhollow, Jr., Envi- Ames, Iowa Columbia ronmental Sciences Division, Oak Ridge National Laboratory, Oak David Archer, USDA–ARS, North- Reviewers ern Great Plains Research Center, Ridge, Tennessee Mandan, North Dakota Harold Reetz (retired), Reetz Ag- ronomics, LLC, Monticello, Illinois

price volatility for food and feed, and Quantifying energy issues within efforts. Corn production (USDA– agricultural energy decisions. any system is difficult, but attempting NASS 2011) rose from approximately The authors conclude by offering an to do so within the constraints of sus- 50 million megagrams (Mg; 2.0 billion approach, including decreased or more tainability (i.e., economically viable, bushels) during the 1930s to 1.55 bil- efficient energy use, that can enhance environmentally benign, and socially lion Mg (12.6 billion bushels) during all aspects of sustainability. Their strat- acceptable) is crucial if humankind is to the past five years (2007–2011) with egy, defined as a “landscape vision,” begin addressing the scientific, tech- no change in harvest area (33.2 million is suggested as an agricultural system nical, economic, social, and political hectares [ha] or 81.99 million acres). approach that could meet increasing elements that must be transformed to The increased production was primarily global demand for food, feed, fiber, and change how energy is generated, sup- because of improved tolerance to high fuel in a truly sustainable manner. plied, distributed, and used (NAS 2010). plant populations and abiotic stress This Issue Paper addresses energy is- (Duvick 1992). Furthermore, the esti- sues within the corn/soybean production mated genetic corn yield potential of 25 Introduction system as a model for understanding the Mg/ha (400 bushels/acre) (Evans and Industrial growth and development, complexities that must be addressed. Fischer 1999; Tollenaar 1983; Tollenaar electrification, rapid advances in trans- The goal is to identify research, devel- and Lee 2002) still has not been portation options, and cheap, abundant opment, and policy needs, questions, achieved across a large area of land, so energy resources during the twentieth benefits, and opportunities for both in- additional increases in yield per unit century allowed many in the United creasing energy efficiency and produc- area and total corn production are antic- States to become very complacent re- ing bioenergy in landscapes dominated ipated as transgenic crops continue to garding both the amount and sources by corn/soybean production systems. improve herbicide tolerance and insect of energy being used. All sectors of the Therefore, this paper will explore en- resistance (Duvick 2005). global economy, including agriculture, ergy issues associated with tillage, There also was a major land use are now being affected by that grow- crop rotation, cover crops, and linkages change (Karlen 2004) as the area de- ing demand for energy because of the among food, feed, fiber, and fuel pro- voted to soybean production increased critical role energy plays in maintaining duction for this cropping system. 500% from 6.1 to 31.9 million ha (15 national security, economic prosperity, to 79 million acres) between 1950 and and environmental quality (NAS 2009). U.S. and Global Corn/ 2010 (CAST 2009; USDA–NASS Understanding the complexity of en- 2011). As a result of these changes, ergy issues affecting agriculture and Soybean Production—1950 the corn/soybean rotation became the all other industries is becoming more to 2010 dominant land use in the midwestern important as world demand for food, As reported by Johnson, Allmaras, United States during the latter half of feed, fiber, and fuel increases and the and Reicosky (2006), corn and soy- the twentieth century (Karlen, Dinnes, reliability of traditional energy sources bean yields were low and constant until and Singer 2010). The development (especially oil) becomes more uncertain after the 1930s. Then, starting with the of highly efficient animal produc- because of political instability and fi- development of hybrid corn; increased tion systems, new products, and an nite supplies. Increasing recognition of use of commercial nitrogen (N), phos- increased global market demand for global climate variability (e.g., ICCAC phorus, and potassium fertilizers; and corn, soybean, and animal products all 2011) and the fact that U.S. dependence development of many mechanical accompanied this increase in corn/soy- on foreign oil has increased from 40% (planters, pickers, combines), chemi- bean supplies. These cropping system in 1990 to 56% in 2009 are just two cal (pesticides, insecticides), and most changes helped ensure a consistent, of the driving forces encouraging ev- recently genetic engineering technolo- uniform commodity supply for agricul- eryone to examine their energy future gies, yields rose steadily through public tural industries; however, with regard to (CAST 2010; NAS 2010). and private research and development soil and water conservation they raised

2 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY many concerns (Karlen, Dinnes, and and Agriculture. It also is the basis megajoule per kilogram N) (see also Singer 2010), and with regard to energy for the North Central Regional SARE Snyder, Bruulsema, and Jensen 2007; consumption they transferred the de- Administrative Council’s position on West and Marland 2002). This type of mand from biomass-supported human energy, which stresses the use of the information may help quantify some and animal power to power sources following (SARE n.d.) for developing energy issues associated with corn/soy- largely dependent on fossil fuels. sustainable biofuel production systems: bean systems. Shapouri, Duffield, and Based on 2003 data from the Food • energy conservation and efficiency Graboski (1995), however, cited esti- and Agriculture Organization (FAO mates of the energy cost of N fertilizer • energy-efficient production practices -1 2010), U.S. corn (maize) accounted for varying from 52 to 87 MJ kg N, de- 40% of the global production. For soy- • non-biomass renewable energy pending on the calculation procedures. bean, a major shift occurred between sources Important considerations include the 1961 when the United States accounted • alternative biomass feedstock pro- time period for which energy informa- for 69% (18.5 million Mg) of global duction systems tion was collected, because industry en- production and 2005 when the United ergy efficiency has changed over time; States provided only 40% of the 206 • environmental impact of bioenergy the differences in formulation of N fer- million Mg (Centrec Consulting Group production tilizer assumed; and whether or not cal- 2007). Brazil (25%) and Argentina • community and rural development culations used the same heating values (19%) are now major world soybean impacts of bioenergy production for various energy sources (Shapouri, producers. These global perspectives • local and regional economic impact Duffield, and Graboski 1995; Snyder, are included to show why it is very dif- of biofuel production Bruulsema, and Jensen 2007). ficult to quantify energy issues in what, The increased supply of corn/soy- to many, might seem to be a simple • whole farm integrated energy systems bean has many different uses, includ- corn/soybean rotation but in reality is Achieving all these goals is a major ing the production of biofuels. With part of a very complex global agricul- reason that quantifying energy issues regard to energy, biofuel production has tural production system, especially in for any agricultural system is such an been promoted for its potential mitiga- the context of sustainability. arduous task. tion of greenhouse gases (GHGs). The rationale is that corn/soybean-derived biofuels are helping to at least stabilize The Definition and Goals of What Energy Issues Affect atmospheric carbon dioxide (CO ) con- Sustainable Agriculture 2 Corn/Soybean Systems? centrations by first absorbing CO2 dur- For this Issue Paper, the term “sus- One of the greatest challenges as- ing photosynthesis and then returning tainable agriculture” (SA) is defined sociated with defining critical energy the same molecules to the atmosphere according to U.S. Code Title 7, Section issues for corn/soybean systems is during combustion. 3103, which states that SA is an in- determining how and where to set the This argument is not always ac- tegrated system of plant and animal system boundaries. This occurs be- cepted because as part of a complex production practices having a site-spe- cause corn/soybean production systems SOS, every change in crop production cific application that will, over the long literally consist of a “system of ecosys- or management influences both en- term, tems” that includes a well-coordinated ergy consumption and CO2 emissions • satisfy human food and fiber needs; mechanical production chain that in (Nelson et al. 2009). For example, to itself can be characterized as a “system decrease energy use and soil erosion • enhance environmental quality of systems” (SOS). The International while simultaneously decreasing CO2 and the natural resource base upon Council on Systems Engineering has concentrations by increasing C (car- which the agriculture economy defined SOS as “a system of interest bon) sequestration, greater adoption depends; whose system elements are themselves of no-tillage practices for corn/soy- • make the most efficient use of non- systems; typically these entail large- bean rotations has been encouraged. As renewable and on-farm resources scale interdisciplinary problems with pointed out by Baker and colleagues and integrate, where appropriate, multiple, heterogeneous, distributed (2007), however, adopting no-tillage natural biological cycles and con- systems” (Duffy et al. 2009). alone may not be sufficient to increase trols; Starting with the corn/soybean pro- soil C retention, and without an in- • sustain the economic viability of duction system itself, there are multiple crease in sequestration there would be farm operations; and subsystems, including tillage, seedbed no mitigation of CO2 concentrations. preparation, fertilization, and weed Quantifying energy issues is thus de- • enhance the quality of life for farm- control. Each subsystem (e.g., fertiliza- pendent on understanding the intercon- ers and society as a whole. tion) encompasses other systems such nected effects of crop sequence, till- This definition (USDA–NIFA 2009) as mining, manufacturing, transporta- age, nutrient management, water use, is a central element of the legislation tion, and marketing that will all have infiltration rate, management decisions, for the U.S. Department of Agriculture costs associated with fossil energy. and many other factors that affect all (USDA) Sustainable Agriculture For example, Shapouri and colleagues ecosystem services (Blanco-Canqui and Research and Education (SARE) pro- (2010) estimated the energy cost of N Lal 2007; Karlen et al. 2009). gram of the National Institute for Food fertilizer alone to be 57 MJ kg-1 N (57 The example just given illustrates

COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY 3 that to quantify energy issues for what and Isserman 2009), especially because incentive for producers to adjust their may seem to be a simple corn/soybean many biodiesel plants are operating use of these inputs in response to chang- rotation is really a very complex pro- well below their constructed capacity. ing energy prices. Fortunately, farmers cess that requires a systematic approach Passage of the Renewable Fuels have historically shown an exceptional to (1) define the problem, (2) identify Standard (RFS; currently updated to ability to make technical and manage- all factors potentially affected by any RFS2) as part of the EISA of 2007 trig- rial changes that improved crop pro- solution, (3) develop concepts for solv- gered many studies, including one by ductivity when faced with increasing ing the problem, and (4) quantify trade- Gallagher (2010) to determine how the energy prices (Cleveland 1995). offs associated with each potential solu- 56.8 billion liter (15 billion gallon) per tion (Karlen et al. 1994). One method year contribution from corn starch- Decreasing Tillage being used to help address this com- based ethanol to the 136.3 billion liter Fuel inputs can be lowered by de- plexity, especially for bioenergy pro- (36 billion gallon) RFS mandate would creasing tillage (Figure 1). The rela- grams, is life cycle assessment (LCA). affect the U.S. corn market. The analy- tive profitability of less intensive tillage This seems to be a good approach, but sis made projections in world corn and systems, such as strip-tillage and no-till it is not an end in itself because of the soybean markets, including effects of compared to conventional tillage, is uncertainty associated with complex technology that will result in yield in- site specific and varies depending on systems and the difficulty in establish- creases and use of the by-product dry soil, climate, and drainage conditions ing the specific boundaries for analysis. distillers grain (DDG) as a replacement (Al-Kaisi and Yin 2004; Archer and for corn feed demand. Based on those Reicosky 2009; Chase and Duffy 1991; Food, Feed, Fuel, and Envi- assumptions, increased corn (maize) Vetsch, Randall, and Lamb 2007; Yin ronmental Interactions production on foreign lands was pro- and Al-Kaisi 2004; Yiridoe et al. 2000). jected to account for only a small Although the decision to decrease till- Currently the U.S. transportation fraction (6%) of the increased grain age is strongly influenced by econom- sector consumes approximately 14 demand associated with meeting the ic returns, the presence of adjustment million barrels of oil per day, 9 mil- RFS mandate. As with energy issues, costs and risk means that producers lion of which are used in light-duty however, the “indirect land use change” will not be willing or may not have vehicles (NAS 2009). Recognizing issue connected to global changes in the capital to invest in new tillage and that consumption likely will increase, crop production is also very complex. planting equipment without some guar- the Energy Independence and Security Increased soybean production asso- antee for a premium in profits above Act (EISA) of 2007 mandated that a ciated with the corn/soybean system what would be earned by their existing portion of domestic fuel consumption is often a major factor in many LCA tillage system (Kurkalova, Kling, and be met with biofuel, which is current- projections related to the RFS2 legis- Zhao 2006). There are several ways this ly supplied primarily by ethanol from lation, but although this topic is very perceived need for premiums could be corn grain or biodiesel from soybean. important, it is beyond the scope of this overcome, including Diversion of corn, soybean oil, and/or Issue Paper and should be addressed by other food crops (e.g., wheat [Triticum future independent studies. 1. ensuring large enough energy price aestivum L.] or peanut [Arachis spp.]) changes that adopting less inten- has stimulated debate regarding com- sive tillage systems is sufficiently petition between food, feed, and fuel Economics of Corn/ more profitable than current tillage (Naylor et al. 2007; Nonhebel 2005; Soybean Systems systems, Trostle 2008) and with respect to po- 2. lowering producer risk through stabi- tential social, economic, and environ- Key Challenges at Each lization policies such as insurance, mental effects. Scale 3. providing better information about In contrast, development of a grain- At the field and farm scale, two the economic impacts of decreas- based ethanol industry has been praised key challenges affecting energy use ing tillage, and for its impact on crop prices and the within corn/soybean systems are (1) beneficial effects it has for rural econo- overcoming barriers to adoption of 4. lowering the adjustment costs of mies (Parcell and Westhoff 2006). energy-conserving production prac- adoption (e.g., through technol- From the perspective of farmers and tices and (2) improving the viability of ogy improvements or subsidizing small rural communities, development bioenergy production. The degree to conservation tillage during the of ethanol plants created greater local which energy issues are captured in the transition from current manage- demand for commodity crops and high- market influences decisions at the farm ment practices). er prices for corn/soybean and other scale. Energy costs represented more Note also that social and environ- crops. Local investment and control of than 44% of total operating costs for mental impacts of agricultural practic- ethanol and biodiesel plants has rein- U.S. corn production and 22% for soy- es may have public costs and benefits vigorated many small midwestern com- bean production in 2004 (Shoemaker, that are not reflected in the market. munities by providing well-paying em- McGranahan, and McBride 2006). Recognizing that these impacts are ployment opportunities, but some argue Prices for energy-intensive inputs (e.g., important in terms of social welfare that the number of jobs added to the fertilizer, herbicides, fuel) directly and long-term sustainability, policies local economy is overestimated (Low influence profitability, providing an and incentives may be implemented to

4 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY energy costs, indicated statistically im- portant increases in conservation tillage and no-till, with producers also indicat- ing that they had decreased N fertilizer rates (Daberkow, Lambert, and Musser 2007). It could not be determined, however, if these shifts were specifi- cally caused by increasing energy costs. These examples highlight some of the economic complexity associated with corn/soybean systems and the energy issues related to them, as well as the need to look beyond direct energy im- pacts. These examples also provide a challenge to identify economically vi- able management practices that can si- multaneously decrease producer depen- dence on tillage, excessive herbicide, or N-fertilizer inputs, while significantly increasing corn and soybean yield. Figure 1. Fuel use as related to tillage intensity (data from Archer and Reicosky 2009). Market Linkages address these impacts. Discussion in this The observed applications, however, The rapid increase in the use of section, however, focuses on the private may be economically rational when con- corn grain for ethanol production has market impacts on farm decisions. siderations of substitutability of other resulted in close linkages between en- farm inputs, opportunity costs, and un- ergy and corn markets, an association Optimizing Nitrogen Use Efficiency certainty about soil and weather condi- that is expected to continue as long as Nitrogen fertilizer represents a sig- tions are included (Sheriff 2005). This demand for ethanol is not constrained, nificant energy and cost input for corn points to the potential for improving N such as by the limit on blending ethanol production. Decreasing N fertilizer use use efficiency by decreasing uncertainty with gasoline (Tyner 2010; Tyner and per unit of production could greatly about soil and weather conditions, as Taheripour 2008). This linkage also ex- lower energy requirements for agricul- well as lowering costs of obtaining in- tends to markets for other crops, includ- ture. Several methods for decreasing N formation regarding soil nutrient status. ing soybean, due in part to competition fertilizer use per unit output have been It is also important to consider in- for land among crops and to competi- identified, including the use of crop teractions among input use decisions tion between crops as inputs for feed rotations, cover crops, and/or manure; at the field level. Although decreasing and manufacturing (Muhammad and banded and decreased fall applications tillage lowers fuel use, increasing fuel Kebede 2009), as well as through effects of fertilizer; and increased use of soil prices will improve the economic vi- of oil prices on currency exchange rates testing, site-specific applications, and ability of less intensive tillage systems. (Harri, Nalley, and Hudson, 2009). N stabilizers or inhibitors (Dinnes et Because of the energy used in the man- With increasing energy prices, al. 2002). These management prac- ufacture of N fertilizers and herbicides, the value of corn for ethanol produc- tices, however, all may incur a cost at however, prices for these inputs are tion also increases. The prices of many the farm level. Increases in N fertil- correlated with fuel prices (Liska and production inputs, however, tend to izer prices provide a market incentive Perrin 2011). Both field research and increase as well. When the values of for producers to decrease N fertilizer producer survey data indicate potential production and inputs both increase, use. Two critical questions with regard significant interactions between till- there may be little economic benefit to to the effects that the various methods age systems and herbicide or N fertil- changing input levels (e.g., N fertilizer) for decreasing fertilizer rates will have izer use (Archer, Halvorson, and Reule inasmuch as economic optimum is of- on energy issues associated with the 2008; Day et al. 1999; Fuglie 1999; ten determined as a function of the ratio corn/soybean production system are (1) Martin et al. 1991; Stecker et al. 1995). of output to input prices (Bullock and Will the savings in N fertilizer expense These interactions may help enhance Bullock 1994; Pannell 1990). There offset the costs associated with imple- energy decreases under increasing may be incentives, however, for gather- menting those practices? and (2) Will energy prices when decreased tillage ing more information (e.g., soil testing the decreases in N rate also lower crop leads to lower herbicide or N fertilizer and plant analysis) because these tools productivity? An alternative strategy use, or these interactions may lower can be used to help avoid under- or for improving N use efficiency would the benefits of decreased tillage if this over-application of N fertilizer. be to increase yield per unit input. leads to higher levels of herbicide or N When crop and fertilizer prices are It often has been suggested that pro- fertilizer use. high, applying an incorrect amount ducers apply more N fertilizer than is Shifts in corn production practice of fertilizer has a greater impact on agronomically needed (Sheriff 2005). from 2001 to 2005, a period of rising profitability, so the benefit of avoiding

COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY 5 incorrect applications increases. So Effland, and Conklin 2005). Although into production. An added concern long as the benefits from obtaining this scale economies have led to larger with using crop residues as a bioenergy information exceed the costs of obtain- farm sizes, there seem to be potential feedstock is whether or not sufficient ing it, adoption would improve farm economic benefits to diversification quantities would be available for har- profitability (Fuglie and Bosch 1995). (Chavas 2008; Morrison et al. 2004). vest while still protecting the soil re- Research has shown that soil testing Diversification could help increase source (Wilhelm et al. 2010). may be complementary with crop rota- energy efficiency of corn/soybean sys- It has been suggested that an ad- tion, presumably by decreasing uncer- tems by taking advantage of production ditional or alternative source of bioen- tainty about the effect of soybean on synergies (e.g., rotations to use nutri- ergy feedstock may be short-rotation N levels for the subsequent corn crop ents better and to disrupt pest cycles; woody crops or perennial grasses (e.g., (Wu and Babcock 1998). Adoption of integration of crops and livestock [even poplar [Populus spp.], willow [Salix both soil testing and crop rotation could though the owner/operators may be spp.], switchgrass [Panicum virgatum], have economic, nutrient use, and ener- different] to use feed and manure bet- or Miscanthus [Miscanthus x gigan- gy use benefits that once again illustrate ter). Diversification, however, can make teus]) grown on sensitive, marginal, the need to consider broader crop pro- management more complex (Chavas degraded, idle, or abandoned lands duction impacts and interactions when 2008), and there is evidence that pro- (Blanco-Canqui 2010; Campbell et al. seeking to optimize energy use efficien- ducers tend to adopt technologies that 2008; Lemus and Lal 2005; Paine et al. cies within corn/soybean or other crop- decrease managerial intensity, particu- 1996; Schmer et al. 2008; Tilman, Hill, ping systems. larly if labor is limited or the farm relies and Lehman 2006). Because these lands As attention shifts to cellulosic heavily on off-farm income (Fernandez- often have low productivity for annual sources for bioenergy production, the Cornejo et al. 2007). The challenge is to crop production or are not currently be- economic viability of cellulosic etha- develop farm diversification or other en- ing used for crop production, using these nol production depends on the total ergy-saving technologies that producers lands for bioenergy production could de- cost of ethanol being competitive with are willing to adopt. This also requires crease the need to bring additional lands other liquid transportation fuels. Crop developing an understanding of the so- into annual crop production. These lands residues have been identified as a po- cial impacts (e.g., health insurance) at also may be where production of peren- tential low-cost source of bioenergy the farm household level. nial feedstock is more profitable than an- feedstocks. Removal of crop residues, nual crop production (McLaughlin et al. however, could lead to declines in soil Regional Scale 2002; Walsh et al. 2003). fertility and productivity, a decrease When expanding beyond the farm Increasing perennial production on in soil C, and an increase in soil ero- level to regional and larger scales, a the landscape, particularly on sensitive sion (Blanco-Canqui and Lal 2009). key challenge is meeting the multiple lands, could provide additional eco- Alternatively, potential benefits could demands for food, feed, fuel, and eco- system service benefits (Tilman, Hill, include a decrease in nitrous oxide system services. At the broader scale, and Lehman 2006). Initial modeling (N2O) emissions from the soil and de- changes in energy prices or policies also questioned whether or not those creased N losses due to leaching (Kim can lead to shifts that affect both crop benefits would be derived if the plants and Dale 2005). Replacement of nutri- and input prices. Analysis of impacts of were harvested, but after sampling ents removed through crop residue har- corn ethanol expansion has illustrated ten farms in the central and northern vest and lost through heightened ero- the importance of understanding the Great Plains, Liebig and colleagues sion increases the costs producers must supply and demand responses, includ- (2008) showed that soil organic C in- recover in selling bioenergy feedstocks ing effects of technological change creased significantly within both the 0 and increases the energy inputs needed (Gallagher 2010). The result may be to 30 centimeter (cm) and 0 to 120 cm to produce those feedstocks. Improving not only changes in management but depth increments. Accrual rates aver- the economic viability of cellulosic changes in land use. Effects on ener- aged 1.1 and 2.9 Mg per hectare per -1 -1 ethanol will require lowering costs and gy issues will depend on where these year (ha yr ) (4.0 and 10.6 Mg CO2 -1 -1 improving efficiencies at all levels of changes occur. Locations of land use ha yr ), respectively; however, there the supply chain, from feedstock pro- change and interactions with manage- was substantial variation across sites, duction to conversion and distribution. ment also have a critical impact on emphasizing the need for additional This includes finding ways to lower nu- provision of ecosystem services, such long-term field studies. Some research trient replacement needs and using co- as differences in GHG emissions (Kim, has indicated that riparian buffers har- products in the best manner to improve Kim, and Dale 2009) or services related vested for bioenergy can be managed to system efficiency (e.g., for process en- to biodiversity and wildlife habitat decrease runoff and sediment transport ergy, feed, or value-added products). (Gottfried, Wear, and Lee 1996). (Sheridan, Lowrance, and Bosch 1999). An attraction of using crop resi- One important consideration is the Farm-level Scale dues as bioenergy feedstock is that this payment amount that producers, par- Expanding from the field to farm feedstock could be produced without ticularly those who specialize in corn/ level, additional considerations be- requiring additional land. This may not soybean production, will receive for come important. There has been a gen- be the case, however, if crop residue establishing and growing perennials on eral trend in the United States toward removal decreases grain yields, thus sensitive lands for bioenergy use. These larger, more specialized farms (Dimitri, requiring additional land to be brought payments may be higher than would be

6 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY indicated by comparing returns from includes research that decreases uncer- ginal land (e.g., Conservation Reserve current annual cropping because of the tainty associated with adoption of en- Program [CRP]), or in large tracts of need for more intensive or diversified ergy-conserving practices and provides marginal land. Simply stated, these management skills. Another concern is opportunities for producers to learn production alternatives will be driven that although land devoted to perenni- about different production practices and by economics, because if farmers can als can be converted back to row crops to develop skills for using those prac- make more money on a piece of land if feedstock prices decrease, at least tices. Some examples are developing by growing switchgrass than by grow- one establishment year is required to technologies that lower the cost of soil ing corn or soybean, they will grow convert cropland back into a perennial testing, gathering information related to switchgrass. From a bioenergy invest- crop such as switchgrass. soil nutrient status, decreasing costs of ment perspective, this emphasizes the Another major challenge associated precision agriculture technologies, and need for stable and predictable policies with accounting for the provision of applying the information to develop on which all management decisions can ecosystem services as part of an over- better knowledge and tools for using be made. all energy analysis is that, even though ecological processes to enhance corn/ management decisions (e.g., what crop soybean production. to plant) are made at the farm level, this The 2010 assessment of North Environmental Challenges is not necessarily the scale at which American soil fertility developed with Facing Corn/Soybean ecosystem services (e.g., wildlife num- data from 4.4 million soil samples bers or filtering and buffering effects) analyzed by private and public soil- Systems are generated or where the benefits are testing laboratories illustrates this Key Issues at Each Scale realized (Fischer, Turner, and Morling type of activity (Fixen et al. 2010). 2009; Gottfried, Wear, and Lee 1996; Unfortunately, those data show that soil and Risks Involved Lant et al. 2005). Increasing the value nutrient levels in some prime produc- When quantifying energy issues of ecosystem services to the farmer, tion areas are not being maintained. associated with agricultural systems, through ecosystem service markets Current agricultural management prac- two of the key environmental risks or policy incentives, could indirectly tices are mining nutrients. Correcting and challenges are climate change and lower energy use associated with corn/ this situation with expanded use of soil land conversion. This is especially true soybean production by providing addi- testing and replacement of nutrients re- in the redesign of existing systems to tional economic incentives to decrease moved by crops is crucial for rebuilding produce biofuels for transportation, in soil erosion and prevent nutrient and depleted nutrient levels. For optimum addition to the food, feed, and fiber that pesticide losses to the environment. production, it is important to maintain they already deliver to a global market. It is also possible, however, that soil productivity and to improve the ef- Rising temperatures increase these incentives could result in practic- ficiency of use for all inputs, including evaporation and generally cause an es that lower production, either through energy. These actions also are crucial increase in the amount of water in the decreased yields or by taking land out for maximizing returns to land, labor, atmosphere. Locally, fluctuations in of crop production (and shifting pro- and capital used in every production rainfall patterns compared to the past duction to less productive regions). If system. Furthermore, these benefits ac- 30-year normal could cause either that is the case, increasing the value of crue across all scales of analysis, from drought or higher precipitation in corn- ecosystem services could increase en- individual fields to farms, to regions, to growing regions. Recent data show that ergy use per unit of production. A key states, to nations, and thus globally. the Corn Belt region has experienced challenge is to predict accurately and to Another research need is the devel- a trend toward higher precipitation understand the interactions that might opment of management systems that events (ICCAC 2011; Karl, Melillo, occur, including effects on land use and allow agricultural production to meet and Peterson 2009). These statistics management decisions. the multiple demands of food, feed, fi- also match the observed record floods ber, fuel, and ecosystem services in the of 2008 in Iowa and Illinois and in Research and Development best ways possible. This will require the Missouri River Valley in 2011. planning beyond a single field or farm; Increasing temperatures lengthen the Needed to Meet Economic to achieve true sustainability, broader growing season, which can increase Challenges economic impacts and provision of yield, but higher temperatures can also Key research needs include find- ecosystems services extending to lo- increase plant respiration, disrupt plant ing ways to lower adoption barriers for cal and regional landscapes also must reproduction (i.e., pollination) and low- energy-conserving practices. Important be included. For example, by adopt- er yields (Karl, Melillo, and Peterson facets of adoption include characteris- ing site-specific management, a portion 2009). In general, climate change im- tics of the learning process, potential of current crop residues could be used pacts are wide ranging and will affect adopters, and conservation practices for bioenergy production, and there all cropping systems, thus reinforcing (Pannell et al. 2006). Achieving net are several scales at which perennials the need for quantitative, long-term re- reductions in energy use will require could be grown on the landscape. These search to fully understand those effects. identification and development of prac- scales include using buffer strips on Internationally, greater industrial- tices that are not only more efficient marginal lands within production and scale demand for bioenergy could in- but also economically superior. This bordering fields, in whole fields of mar- crease economic pressure to convert

COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY 7 native ecosystems to agricultural sys- bon debt that would take 48 years to the form of N2O from N fertilizer con- tems (Naylor et al. 2007; Searchinger et repay. The assumption associated with tribute roughly 36% of cropping GHG al. 2008). To minimize deforestation for this estimate, however, was that tillage emissions from corn, although great un- agricultural expansion in places such would be used for the conversion. This certainty exists (Liska and Perrin 2011). as Brazil, overall productivity from may not be accurate because technol- Changes in SOC may be a large agricultural lands must be increased to ogy now exists to make the conversion source of GHG emissions from biofuel meet fuel, feed, fiber, and food needs. using no-till practices. Field studies by production (Wortmann et al. 2010), but Failure to develop more productive Follett and colleagues (2009) provide the science of soil C dynamics has been systems will likely ensure that in the data showing that use of no-till farm- questioned in recent years with contro- long term, native ecosystems will be ing practices to convert CRP grasslands versial and conflicting data (Baker et diminished even more than they are to grain crop production does conserve al. 2007). Overall, the results seem to now (Hassan, Scholes, and Ash 2005; the soil organic carbon (SOC) that was differ because of production practices, UNEP 2009). The United Nations sequestered during the time period that depth of soil sampling, and the agro- Environmental Programme projects the land was in the CRP. The potential ecosystem within which the research global biofuel expansion by 60 to 80 conversion of CRP land in the United was conducted (Blanco-Canqui and million hectares (Mha), or even 166 States is also controversial because of Lal 2008; Varvel and Wilhelm 2011; Mha, by 2020. This is equivalent to be- its wildlife and other ecosystem service Verma et al. 2005). Fortunately, there tween 4 and 11% of the current arable benefits. The most satisfactory option is greater data congruence concerning land or 1 to 3% of total global agricul- for addressing these differences would SOC dynamics and residue removal. tural land (UNEP 2009). be a science-based approach that ad- Summaries of recent field studies show Further decreases in native eco- dresses all ecosystem services, including that SOC is consistently lost when crop systems could easily increase the rate biofuel feedstock production, in a com- residues are removed at excessive rates of species extinction and potentially prehensive economically, environmen- (Anderson-Teixeira et al. 2009; Blanco- lead to the irreparable losses of bio- tally, and socially acceptable manner. Canqui and Lal 2009; Wilhelm et al. diversity that are of concern to many 2007); however, there is a large amount people today. In addition, conversion of of variability in the results and con- native ecosystems to agricultural uses Life Cycle Assessment as a tinued, long-term studies (e.g., Karlen often is associated with a large loss Tool 2010; Karlen et al. 2011) are needed to of C through both the destruction of Life cycle assessment is a method help quantify SOC changes associated standing biomass associated with trees, for evaluating the full environmen- with crop residue harvest. grasses, and forbs within the natural tal impact of any industrial production The nexus of biofuels, climate system and the oxidation of soil organic system. It is now being used to evaluate change, and land use conversion has be- C when the area is disturbed through the GHG emissions from the produc- come an important LCA issue for biofu- tillage or other processes. The newly tion of biofuels relative to conven- els (Searchinger et al. 2008). So-called released C is quickly oxidized to CO2, tional petroleum fuels. Recent passage “indirect land use change” from the pro- which is recognized as a leading driver of the Low Carbon Fuel Standard of duction of biofuels assumes that corn of climate change. California and the EISA both require taken out of the market is partially re- In the United States, the land con- decreases in GHG emissions from bio- placed by crop expansion and deforesta- version issue is controversial because fuels compared with gasoline. Because tion abroad. But there is a high level of of different assumptions regarding of the flexibility of LCA, it is an appro- uncertainty in projections of additional potential soil and crop management priate method for attempting to gauge GHG emissions from land use change practices that might be used by land the total GHG intensity of fuels and for inclusion in the corn-to-ethanol life managers and decision makers. Further the degree to which different fuels will cycle, ranging from 14 to 104 grams conversion of native tallgrass prairie is decrease emissions that cause climate CO2 equivalent per megajoule (MJ) of quite limited because nearly all of the change (Liska and Perrin 2009). Life energy in ethanol (Wang et al. 2011). area that can be converted to cropland cycle assessment has yet to be required Overall, these assumptions have numer- has been tilled. Most remaining areas by legislation to monitor non-biofuel ous areas of contention at present and of tallgrass prairie are too rocky, shal- food crops, although emerging market- are dependent on actions and policies low, steep, sandy, or isolated in small ing methods used by Walmart will use of independent countries. Because of patches to be farmed economically. LCA to quantify the environmental im- the uncertainties involved, it may not be The potential impact of returning pact of food products (Walmart 2011). possible to reliably model the indirect CRP land to crop production is being To understand the LCA process, effects of biofuels outside of the country vigorously debated among different users must first determine the sum of in which they are produced. groups. For example, Fargione and col- GHG emissions from the use of fos- leagues (2008) calculated that convert- sil fuels in biofuel production. This is Research and Development ing central U.S. farmland that had been relatively straightforward using USDA enrolled in the CRP for 15 years to a statistics, although data for the biofuel Needed to Prevent Environ- corn ethanol production system would industry are more scarce (Liska et al. mental Problems decrease both standing biomass and 2009). In addition to both direct and in- From an LCA perspective on bio- soil carbon, thus creating a biofuel car- direct fossil fuel use, GHG emissions in fuel production, one of the most critical

8 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY factors for determining net GHG emis- produced with natural gas. Beginning leum, gasoline, ethanol, and corn, as sions is likely to be changes in SOC. in 2006, the price surge in a wide range an example, would be tightly bound Long-term field data remain limit- of commodity prices signaled the because demand for ethanol and there- ed (e.g., Follett et al. 2009; Liebig et emergence of a new relationship, en- fore feedstock supplies would be al. 2008) because quantifying SOC couraged by state and national energy highly elastic (Tyner 2007; Tyner and changes associated with crop residue policy, between agricultural and energy Taheripour 2008). Over certain ranges markets. With it came a surge in de- or prices and given time to adjust, de- removal is a long-term process that re- mand for feedstocks from the agricul- mand for feedstocks to produce biofu- quires substantially more investment tural sector to be used for energy pro- els may be highly elastic and stabilize in research, especially on marginally duction. Some saw biofuels as a means corn prices with respect to shocks1 that productive cropland. The Agricultural to decrease C emissions, increase originate in agricultural markets, but Research Service (ARS) Renewable energy independence, and raise farm the level at which the price stabilizes Energy Project and Sun Grant Regional income. Others noted that the new de- is contingent on the price of petroleum Partnership are two sources of informa- mand for commodities to produce bio- and therefore subject to its fluctua- tion that are beginning to provide some fuels could lead to higher food prices, tions. With petroleum second only to of the field data needed to quantify potentially undermining food security agricultural markets in price volatility long-term effects of residue harvest on and bringing about unintended environ- (Regnier 2007), the net effect on price SOC (e.g., Karlen 2010; Karlen, Birrell, mental consequences from expanding volatility, even under a very elastic re- crop acreage that may actually result in lationship, is unclear. and Hess 2011; Karlen et al. 2011; greater C emissions. They also called To support the U.S. biofuel indus- Wilhelm et al. 2010), but additional into question the use of policy initia- try, subsidies often have been provided studies are needed. tives to promote the transformation of to encourage production and consump- The best strategy to resolve the food crops into energy. tion of biofuels derived from corn/soy- large uncertainties associated with The increase in prices during this bean oil. The policy followed during geographical variations in climate, period threatened to push millions of recent decades historically has been a soil, and management practices is to additional people toward hunger and subsidy provided to biofuel blenders. fully support critical long-term field undernourishment (FAO 2008). As a A portion of the subsidy is passed back research to quantify and better under- result, a large number of studies were to the producers, which encourages fur- stand the subtle relationships between conducted to examine the share of the ther biofuel production, and part of the crop residue removal and SOC loss. increase that could be attributed to bio- subsidy is passed forward to consum- Furthermore, where cost effective, fuel production, and these studies have ers, lowering the price and encourag- resulted in a wide range of conclu- ing consumption. This policy, although management of crop rotations and resi- sions (CEA 2008; Collins 2008; Trostle intended to promote biofuel production, due, as well as manure from livestock, 2008). During this same period, the has in essence become a subsidy that can play a role in maintaining soil C United States, the European Union, and encourages greater fuel consumption (Fronning, Thelen, and Min 2008). Brazil continued and expanded sup- to support driving more vehicle miles, Alternatively, after biofuel production port programs for biofuel production. which is in contrast to rising oil prices the return of a stable C residue in the During 2009, prices fell from those that discourage additional driving form of biochar could be important for highs but remained well above historic (Lapan and Moschini 2009). Subsidies helping to maintain SOC and decreas- levels. During 2010, wheat crop fail- such as this also are government expen- ing overall GHG emissions from biofuel ures in Russia and lower corn yields in ditures that totaled approximately six systems (Lehmann and Joseph 2009). many areas of the United States again billion dollars in 2010. As environmen- Thus, in addition to a more comprehen- raised concerns regarding the impact tal concerns have increasingly become of biofuel production on food prices. a motivation for biofuel use, policies sive approach for estimating SOC loss, These events highlight the importance that in essence subsidize consumers for more research is needed on manage- of understanding how the world’s bio- driving more miles are being looked on ment strategies that maintain or even fuel production and energy policies less favorably by many people con- enhance SOC levels. influence commodity prices and how cerned about U.S. federal expenditures. they may contribute to price volatility The Energy Policy Act of 2005 es- in agricultural markets. tablished nationwide use mandates for Market and Policy Issues Several studies (Elobeid et al. 2006; biofuels in the United States, and these for Corn/Soybean Gallagher, Otto, and Dikeman 2000; mandates were further expanded by the Meyer, Westhoff, and Thompson 2008; EISA. If continued, these mandates will Systems Westhoff, Thompson, and Meyer 2008) require more than a doubling of renew- Agricultural commodity markets have shown the area and price effect able fuel consumption in the United traditionally have been influenced by to date of various renewable fuel poli- States during the next decade. Much of energy price movements through pro- cies on agricultural commodity prices. duction and distribution costs. Changes Given the relative size of petroleum 1 Italicized terms (except genus/species names were felt both directly in fuel costs and and biofuel markets, it was previously and published material titles) are defined in the through other inputs such as N fertilizer assumed that linkages among petro- Glossary.

COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY 9 the growth beyond 2010 could come sugarcane [Saccharum spp.] bagasse), from “second generation” biofuels, and production of those materials which excludes corn starch-based etha- could impact corn and soybean acre- nol under current legislation (Service age. Furthermore, the RFS2 mandate 2010). Several feedstocks thought to represents minimums, and should pe- be viable sources for cellulosic biofuel troleum prices rise to levels reached in production, such as dedicated grasses 2007, the market could easily increase or crop residues, however, will contin- demand for biofuels to levels exceed- ue to influence corn and soybean acre- ing these quantitative minimums. This age into the future. remaining growth in biofuel production Similar quantitative mandates directly from corn/soybean, coupled for biofuel programs in the European with the potential for simultaneous Union set a target of 10% renewable growth in both oil and agricultural fuel inclusion by 2020 (EUC 2009). commodity prices, represents the pri- Figure 2. Quantitative mandates mary policy and market challenges for These quantitative mandates have the produce a highly inelastic effect of creating a highly inelastic demand when they are binding. corn/soybean-based energy systems. segment of demand (Figure 2), which As was seen in 2007, the simulta- means the quantity of fuel consumed neous rise in both petroleum prices and is being dictated and not respond- and, instead of categorizing fuel types food prices, along with increased use ing to market signals, and thus price into four classes, establishes a GHG of corn for ethanol, attracted increased movements can be exaggerated. Such reduction score for each fuel pathway scrutiny of policies that encouraged mandates, while adding certainty for or alternative to fuel such as electric diversion of food and feed crops to pro- biofuel producers and feedstock sup- vehicles. Should the separate system duction of biofuels. Although numerous pliers, mean this segment of demand is be employed, it could greatly alter the studies concluded this was but one fac- less able to respond to feedstock supply fuel pathways being used to com- tor contributing to the rapid rise in food shocks such as drought, causing a large ply with the national RFS, and fuels costs (CEA 2008; Collins 2008; Trostle rise in agricultural prices even when and technology of the greatest value 2008), it is fair to say corn ethanol- petroleum prices are stable. It is left to in California could spur production. and soybean oil-based biodiesel took a other grain users (e.g., food and feed) Should other states follow California’s public image hit (Selfa et al. in press; to adjust consumption. This again has move, greater quantities of total bio- Skipper et al. 2009). Even if a starch- the potential for leading to increased fuels than required under the RFS2 based process were in place that would commodity price volatility. may be necessary and thus could have result in the 50% GHG reduction score Additional proposals that span important quantitative effects on the needed to qualify as a GHG mitigation other energy sectors, such as the U.S. sector. strategy, it is legislatively prohibited House of Representatives bill HR2454, from doing so and thus suffers from which is often referred to as “Cap and the label of old technology. The biofuel Trade,” will expand the role of quanti- Key Challenges at Each industry will continue to grow under tative mandates influencing the agricul- Scale current policy and at such a scale in ture sector. Under renewable portfolio At the scale of state and national the United States that the perception of standards for electrical generation, the policy, the part of the total RFS2 man- causal linkage among petroleum prices, use of biomass to cofire with tradition- date that corn starch ethanol can ac- biofuel demand, and commodity prices al feedstocks in electrical generation cess is capped at 56.8 billion liters (15 will continue to add uncertainty to the could put cap and trade policy in direct billion gallons), which represents an market regarding the continuation of competition with biofuel policy. If ap- approximate 25% increase in produc- the quantitative biofuel mandates. proved, this bill could add additional tion when compared to the 45.4 billion Another real concern is the abil- rigidity to commodity demand and ac- liters (12 billion gallons) produced in ity of the motor fuel infrastructure to companying volatility in corn/soybean 2009. The RFS2 biodiesel mandate, handle an increased volume of ethanol prices. for which soybean oil can be used, and biodiesel. To date the “blend wall” While the United States has pur- grows a little over 50% after 2010 to has been a concern, because conven- sued biofuel policies at a national a total volume of 3.8 billion liters (1 tional vehicles previously were limited level, several states have or are pro- billion gallons). So although there will to a maximum 10% ethanol inclusion in posing their own policies. Some states, be continued growth in the production motor fuels, with an aggregate gasoline such as Missouri, have a minimum of these two fuels, much of the man- market of approximately 548.9 billion blend requirement for ethanol; as the dated volume coming directly from liters (145 billion gallons) per year, ac- national mandate grows, this policy corn/soybean has already been met. cording to the Department of Energy. becomes less important. New state pro- But the RFS2 mandate requires another As a result, this market is being satu- posals could be far more influential. 79.5 billion liters (21 billion gallons) rated quickly. California’s Low Carbon Fuel Standard of biofuels to be derived from other The transition to higher blends mandates a reduction in GHGs emit- feedstock materials (e.g., corn stover, such as E85 (up to 85% ethanol) re- ted from the transport sector in the state switchgrass, Miscanthus, sorghum, quires new dispensing infrastructure

10 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY and specialized vehicles. This invest- process, or subsequently spun out of improve infrastructure for the dispens- ment takes time, and with the pos- the distillers grains, could both provide ing of higher-level blends. Current sibilities of mandate waivers, policy a biodiesel feedstock and potentially availability of E85 pumps is limited changes, and expansion of lower-level expand the use of the distillers grains geographically to the Midwest in states blend constraints, investment by mo- into other livestock types where the oil that represent only a small share of mo- tor fuel dispensers remains a risky content may be an impediment. The use tor fuel consumption (RFA 2005–2011). prospect. Recently the Environmental of these additional feedstocks would This represents only part of the demand Protection Agency (EPA) allowed for increase the output of ethanol per ha of constraint. Flex fuel vehicles remain a up to 15% blends in conventional ve- corn production and lessen competition small share of the overall vehicle fleet hicles produced in 2002 or later, but it with or even enhance food, feed, and and, unless high-level blends are priced isn’t clear if this ruling will alleviate fiber production. based on energy equivalence or below, the bottleneck. The bifurcation of the For soybean oil-based biodiesel, the incentive to purchase E85 vehicles conventional vehicle market may raise the way forward is less clear. Only in- or use those already on the street will consumer confusion, and fuel retail- creases in seed yield or oil content are be limited. ers have expressed concerns that such likely to produce additional quantities bifurcation exposes them to consumer of biodiesel per ha and lessen compe- A Landscape Vision for complaints and lawsuits resulting from tition for food use. A more likely path misfueling. for increasing biodiesel production is Sustainable Corn/Soy- The EPA waived the cellulosic bio- to use other feedstock materials. In bean Systems fuel mandate in both 2010 and 2011 the review by Johnson and colleagues Developing a landscape vision (Lane 2010; Service 2010). Should the (2007), the authors stated that sev- (Figure 3) that blends multiple feed- hurdles in economic cellulosic biofuel eral species from the mustard family stock streams is one strategy for engi- be overcome and should a significant (Brassicaceae) could be viable candi- neering more sustainable and energy- portion of that supply be in the form dates for biodiesel and other advanced efficient corn/soybean production of ethanol production, the blend wall fuel production. Potential crops in- practices. The premise for this vision limit to total U.S. market demand for clude oilseed rape (Brassica napus L.), is that rather than focusing solely on ethanol would more likely be hit and crambe (Crambe abyssinica), lesquer- energy issues associated with the corn/ thus create additional hurdles that will ella (Lesquerella fendleri [S. Wats.]), soybean system, the challenge could be affect the distribution and consumption camelina (Camelina sativa L.), penny- addressed through coordinated efforts of biofuels produced under current do- cress (Thlaspi arvense L.), castor bean that also mestic mandates. Development of ad- (Ricinus communis L.), and Cuphea vanced drop-in fuels may help alleviate spp. (plant family Lythraceae), and they • provide sustainable grain and this issue, but substantial research and are currently under investigation. An biomass feedstock supplies for the development is still needed to make advantage for crambe and camelina is bioenergy industry, such fuels viable. that neither is currently being grown • increase C sequestration, widely in the United States and, be- • protect water quality, cause they are both being developed for Research and Development industrial uses, conversion to biodiesel • increase productivity and profitability, Needed to Meet Market will not compete directly with soybean • lessen producer and environmental Challenges or other edible-oil crops. risk, A second alternative that has al- Advancements in corn/soybean • promote biodiversity, yield through increased productivity ready been seen is the extensive use of will help alleviate supply concerns, but animal fats in combination with soy- • improve wildlife habitat, and issues associated with GHG profiles, al- bean oil. Another option, depending • enhance rural community develop- ternative feedstock supplies, and efforts on the region, would be to use double- ment by creating new industries and to overcome bottlenecks in use are all cropping of an oil crop with a conven- entrepreneurial opportunities. tional summer crop or even to dou- targets for additional research and mar- This approach also could facilitate bal- ket development. ble-crop two oilseed species. Finally, substantial effort also is being given to ancing the economic drivers and sus- The corn production system is ca- tainability factors (Figure 4) needed to pable of contributing additional feed- second generation feedstock materials such as algae. All of these oil sources have sustainable feedstock supplies. stock, from corn residue to the pericarp The landscape vision for sustain- removed before fermentation, for use are attracting attention and may lead to more competition for soybean oil in the able resource management is built on in the production of cellulosic ethanol. experiences with field-scale precision The use of either of these feedstocks biodiesel sector, thus decreasing price volatility for soybean oil. farming (Kitchen et al. 2005; Lerch et could produce a fuel that could qualify al. 2005). It begins by geo-referencing as an advanced biofuel and, depend- Economically, the biofuel indus- try has already signaled a willingness a site and developing a detailed soil ing on the process, perhaps a cellulosic survey, a digital elevation model, and biofuel (which depends largely on SOC to forgo extension of the blenders’ credit and has offered an alterna- soil fertility maps. Information such as dynamics, as shown earlier). Corn oil current land tenure, community access removed during the dry grind ethanol tive focused on investment credits to

COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY 11 and fiber needs. Where climatically possible, erosion and C loss could be partially mitigated by using cover crops or living mulches. The crucial point is that plant species variation across the landscape would be much greater than the corn/soybean-dominated landscapes that currently exist throughout much of the midwestern United States. Incorporation of red clover or alfal- fa to serve as a cover crop and/or green manure could significantly alter energy flow in current corn/soybean systems, because these crops have been shown to have an N replacement value ranging from 70 to 121 kg N ha-1 (Liebman, M. 2010. Personal communication). Based on an N fertilizer cost of 57 MJ kg-1 N (Shapouri et al. 2010), this level of synthetic N replacement would repre- sent a fossil fuel savings ranging from 4 to 10 gigajoule ha-1, which is equiva- Figure 3. A landscape management vision serves to more fully integrate eco- lent to the energy content of 104 to 274 nomic, environmental, and social aspects of agriculture into agronomic cubic meters of natural gas (Oak Ridge systems to produce food, feed, fiber, and fuel sustainably. (Photo cour- National Laboratory 2009). Food and tesy of USDA–Natural Resources Conservation Service.) feed supplies would not be endangered because there still would be intensive row-crop production areas established using best management practices. This establishment would occur with the awareness that if fertilizer recovery was less than desired, there would be a sub- stantial buffer (lignocellulosic) produc- tion area lower on the landscape to cap- ture residual nutrients and sediment. Development of multiple feedstock streams for sustainable biofuel produc- tion could be coupled with greater use of coproducts from current corn/soy- bean biofuel production systems. This might include using manure generated by animals consuming the DDGs as a fuel source for methane production via anaerobic digestion. Wind energy also could be captured and used to decrease the current energy flow associated with Figure 4. An illustration of competing economic drivers and environmental sus- corn/soybean production and/or con- tainability forces that must be balanced to achieve sustainable cellu- version systems. losic feedstock supplies to support the transition from fossil to renew- able fuels (from Wilhelm et al. 2010; used with permission of Mary Ann Implementing an integrated feed- Liebert, Inc., Publishers). stock vision is not without its own challenges, but its strength is the op- relationships, soil resource and drain- fuel production schemes that could en- portunity to begin addressing multiple age patterns, soil quality status, crop hance ecosystem services. One hypo- environmental and production issues by rotation and distribution patterns, eco- thetical scenario would be to establish striving for a more balanced agricultur- nomic conditions, conservation prac- woody species such as poplar trees near al ecosystem. Development of an inte- tices, wildlife, and human restrictions streams, grass and legume species in grated landscape vision is feasible and and concerns is then added as “layers” a buffer area between the streams and could be done efficiently and economi- to the base maps. Karlen, Dinnes, and cropland, and then high-yielding diver- cally if there is a desire and public will- Singer (2010) discussed this approach sified rotations of annual and peren- ingness to do so. Agriculture in its full- with regard to the development of bio- nial crops that would meet food, feed, est capacity has the potential to address

12 COUNCIL FOR AGRICULTURAL SCIENCE AND TECHNOLOGY multiple economic, environmental, and is the fact that the emerging biofuel 8. develop consistent federal, state, social goals in a sustainable manner industry is changing daily because of and local policies for bioenergy (Karlen, Dinnes, and Singer 2010). The the increased recognition that current development to provide guidance key is recognizing that current agri- energy supply sources are finite and for private and public investment. cultural practices, developed using an often located in areas that may or may Addressing these needs and answer- industrial model of component sepa- not have political stability. Although ing many other questions will enable ration for efficiency, are not necessar- controversial and not fully understood, legislation such as the EISA of 2007 ily consistent with ecological models the effects of rising GHG concentra- and other subsequent laws to be imple- of redundancy (an ecological term that tions are another consideration affect- mented. The answers also will help is sometimes referred to as functional ing energy issues associated with this increase energy, nutrient, and water use compensation, meaning that more than cropping system. In response, many efficiencies associated with corn/soy- one species can perform a given role). conferences and workshops have been bean cropping systems and collectively held to address multiple questions as- help ensure that the United States truly sociated with the emerging biofuel in- Summary and Conclusions achieves the ultimate goal of having en- dustry. Some recent examples include ergy independence and security. This Issue Paper focuses on critical a Soil and Water Conservation Society- energy issues affecting corn/soybean sponsored event that focused on systems by first establishing the global “Sustainable Feedstocks for Advanced lossary production framework for these crops; G Biofuels” in which all aspects of pro- Blend wall. The maximum possible then reviewing the Farm Bill crite- duction, harvest, storage, and transport ria defining sustainability; and finally volume of ethanol that can be blend- of biofuels feedstocks were examined. ed into U.S. motor gasoline. Initially examining economic, environmental, Another is the development of Regional and market factors affecting energy use set at 10% by volume, it was re- Bioenergy Research Centers by the cently raised by the EPA to 15% for and efficiency. An integrated landscape USDA–ARS and the USDA–Forest vision is then offered as one strategy vehicles built in 2002 or later. Service. Despite those and many other Pericarp. The outer wall of a fruit or, for developing more sustainable and actions, several questions and long- energy-efficient corn/soybean systems. in this case, the corn kernel that term needs remain unanswered. These protects the seed or germ itself. It is With regard to economics, a criti- include the need to cal need is to find profitable ways to made up of a tough outer skin, the decrease adoption barriers for energy- 1. develop protocols for quantify- fleshy middle layers, and the inner- conserving practices. Some possible ing energy flow through complex most layer, known as the endocarp, approaches would be to identify man- systems that are themselves either that surrounds the seeds. agement strategies that would lessen “systems of ecosystems,” “systems Shocks. Unanticipated changes in com- uncertainty associated with adoption of systems,” or both; modity supply or demand associ- of energy-conserving practices and to 2. quantify real versus perceived ated with yield variation that is not provide opportunities for producers to effects of no-tillage on C seques- expected because of the occurrence learn about different corn/soybean pro- tration and the associated GHG of drought, flooding, abnormal tem- duction practices and develop skills for mitigation value; peratures, conflict, or even per- fect weather that causes anticipated using those practices. 3. find ways to decrease adoption Two environmental risks and chal- yields to deviate from the “normal” barriers for energy-conserving or long-term “trend.” lenges affecting energy issues associat- practices; ed with corn/soybean systems, especial- 4. develop integrated landscape ly with regard to their role in bioenergy iterature ited production, are climate change and land management plans that maximize L C conversion. These issues are exam- the productivity, the efficiencies of Al-Kaisi, M. and X. Yin. 2004. Stepwise time ined by using LCA as a tool. One of the land, water, and nutrient use, and response of corn yield and economic return to the profitability while simultane- no tillage. Soil Tillage Res 78:91–101. most critical research needs associated Anderson-Teixeira, K. J., S. C. Davis, M. D. Mas- with this tool is to develop consistent ously conserving or minimizing ters, and E. H. DeLucia. 2009. Changes in soil system boundaries when comparing energy flow; organic carbon under biofuel crops. Global Change Biol—Bioenerg 1:75–96. biofuels and fossil fuels. With regard to 5. develop more comprehensive Archer, D. W. and D. C. Reicosky. 2009. Economic market forces, advancements in corn/ quantitative estimates of changes performance of alternative tillage systems in soybean yield through increased pro- in SOC from crop residue removal the northern Corn Belt. Agron J 101:296–304. Archer, D. W., A. D. Halvorson, and C. A. Reule. ductivity will help alleviate supply con- and resulting GHG emissions; 2008. Economics of irrigated continuous corn cerns. But issues associated with GHG 6. develop policies and incentives under conventional-till and no-till in northern profiles, alternative feedstock supplies, that encourage more holistic land Colorado. Agron J 100:1166–1172. and efforts to overcome bottlenecks in Baker, J. M., T. E. Ochsner, R. T. Venterea, and management and facilitate rural T. J. Griffis. 2007. Tillage and soil carbon use are all critical topics needing ad- development and entrepreneurial sequestration—What do we really know. Agric ditional research, development, and opportunities for agriculture; Ecosys Environ 118:1–5. policy evaluations. Blanco-Canqui, H. 2010. Energy crops and their 7. develop integrated usage of renew- implications on soil and environment. 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CAST Member Societies, Companies, and Nonprofit Organizations AMERICAN ACADEMY OF VETERINARY AND COMPARATIVE TOXICOLOGY/AMERICAN BOARD OF VETERINARY TOXICOLOGY n AMERICAN ASSOCIATION OF AVIAN PATHOLOGISTS n AMERICAN ASSOCIATION OF BOVINE PRACTITIONERS n AMERICAN ASSOCIATION OF PESTICIDE SAFETY EDUCATORS n AMERICAN BAR ASSOCIATION, SECTION OF ENVIRONMENT, ENERGY, & RESOURCES–AGRICULTURAL MANAGEMENT n AMERICAN DAIRY SCIENCE ASSOCIATION n AMERICAN FARM BUREAU FEDERATION n AMERICAN MEAT SCIENCE ASSOCIATION n AMERICAN METEOROLOGICAL SOCIETY, COMMITTEE ON AGRICULTURAL AND FOREST METEOROLOGY n AMERICAN SOCIETY FOR NUTRITION n AMERICAN SOCIETY OF AGRICULTURAL AND BIOLOGICAL ENGINEERS n AMERICAN SOCIETY OF AGRONOMY n AMERICAN SOCIETY OF ANIMAL SCIENCE n AMERICAN SOCIETY OF PLANT BIOLOGISTS n AMERICAN VETERINARY MEDICAL ASSOCIATION n AQUATIC PLANT MANAGEMENT SOCIETY n COUNCIL OF ENTOMOLOGY DEPARTMENT ADMINISTRATORS n CROPLIFE AMERICA n ELANCO ANIMAL HEALTH • IOWA SOYBEAN ASSOCIATION n LAND O’LAKES n MONSANTO n NATIONAL CATTLEMEN’S BEEF ASSOCIATION n NATIONAL PORK BOARD n NORTH CENTRAL WEED SCIENCE SOCIETY n NORTHEASTERN WEED SCIENCE SOCIETY n NOVUS INTERNATIONAL, INC. n PIONEER, A DUPONT BUSINESS n POULTRY SCIENCE ASSOCIATION n SOCIETY FOR IN VITRO BIOLOGY n SOCIETY OF NEMATOLOGISTS n SYNGENTA CROP PROTECTION, INC. n THE FERTILIZER INSTITUTE n UNITED SOYBEAN BOARD n WEED SCIENCE SOCIETY OF AMERICA n WESTERN SOCIETY OF WEED SCIENCE The mission of the Council for Agricultural Science and Technology (CAST) is to assemble, interpret, and communicate credible science-based information regionally, nationally, and internationally to legislators, regulators, policymakers, the media, the private sector, and the public. CAST is a nonprofit organization composed of scientific societies and many individual, student, company, nonprofit, and associate society members. CAST’s Board is composed of representatives of the scientific societies, commercial companies, nonprofit or trade organizations, and a Board of Directors. CAST was established in 1972 asaresultof meeting sponsored in 1970 by the National Academy of Sciences, National Research Council. ISSN 1070-0021

Additional copies of this Issue Paper are available from CAST. Linda M. Chimenti, Chief Operating Officer. http://www.cast-science.org.

Citation: Council for Agricultural Science and Technology (CAST). 2012. Energy Issues Affecting Corn/Soybean Systems: Challenges for Sustainable Production. Issue Paper 48. CAST, Ames, Iowa.

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