Science and Sustainability in U.S. Agriculture Kenneth G. Cassman

1. Science and Sustainability in U.S. Agriculture Kenneth G. Cassman Director, Nebraska Center for Energy Science Research (www.ncesr.unl.edu) University of Nebraska AAAS Annual Meeting

2. Topics • U.S. and global agriculture undergoing a biofuel revolution • The first phase based on food crop conversion to biofuels plays out within next 10 years • Is causing an abrupt increase in the value of crop commodities and arable land • From food surplus to food scarcity in two years! • Impact on focus of agricultural sustainability • Changes in scientific emphasis and funding priorities • Critical need to bet on winners (higher batting average): hype to reality ratio AAAS Annual Meeting

3. Global Importance of U.S. Agriculture • Largest global exporter of staple food and oilseed crops • 60% of maize* • 44% of soybean* • 36% of rice* • 27% of wheat* *2004 • Largest humanitarian food donor • 56% of global total for cereals (2002 & 2003) AAAS Annual Meeting

4. Challenges to Sustainable Agriculture • Population growth and rapid economic development in developing countries • Higher incomes, richer diets with more livestock products • Limited arable land suitable for crop production • Climate change, especially warmer temperatures and greater variability • Rising prices for petroleum and other forms of energy • Makes use of food crops for biofuel production a profitable proposition AAAS Annual Meeting

5. The 18-month biofuel agricultural revolution no one predicted (8-06 to 1-07) • Oil prices jumped to new highs after hurricane Katrina and will likely stay at elevated levels • Congress passed the 2005 Energy Policy Act mandating a 7.5 billion gallon Renewable Fuel Standard by 2012 • Large venture capital flows to the U.S. biofuel industry • Ethanol production capacity will reach 11.6 billion gallons by end of 2008 • Other countries too (Brazil, Indonesia, Europe) • Corn and other biofuel crop prices have risen dramatically AAAS Annual Meeting

6. Energy Consumption and Income are Linked 5 billion low-income people in countries with rapid economic growth rates AAAS Annual Meeting

7. Oil Consumption Much Great Than Oil Discovery AAAS Annual Meeting

8. Compelling Biofuel Benefits • Decreased reliance on imported petroleum • Net reduction in greenhouse gas emissions • Increased agricultural commodity prices and farm income • Reduction in need for crop subsidies • Rural jobs and economic development AAAS Annual Meeting

9. Convergence of energy & agriculture • Corn price is now being determined by the value of corn grain as a feedstock for biofuel • While soybean is less competitive as a biofuel feedstock, soy prices will be determined by the value of other oilseed crops used for biofuel feedstock (oilseed rape, oil palm) • Increased demand for grains and oilseeds will raise the price of all agricultural commodities (including hay and cellulosic feedstock!), as well as land and water AAAS Annual Meeting

10. 12 billion gal by 2009¶ USA Ethanol Production Capacity 15 billion gal by 2015?¶ ¶Will require 36% and 46% of US corn in 2010 and 2015, respectively, assuming +10% increase in corn acres and trend-line yield growth. AAAS Annual Meeting

11. Expansion of Biofuel Production is a Global Phenomenon • Brazil: tremendous capacity to increase ethanol production from sugarcane, biodiesel from soybean and perhaps oil palm • Indonesia/Malaysia: rapid expansion of biodiesel from oil palm (perhaps also Nigeria and DR-Congo) • Europe and Canada: expansion of biodiesel from canola AAAS Annual Meeting

12. Actual global trends in cereal harvest area 1981: 727 million ha  2003: 666 million ha AAAS Annual Meeting Source: FAOSTAT

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14. The Promise of Cellulosic Ethanol • Mostly avoids direct food vs fuel competition • Indirect competition for land • Large amount of cellulosic biomass feedstock could support substantial expansion of ethanol production capacity • May have greater positive environmental impact than corn grain ethanol: larger reduction in GHG emissions, better protects soil quality, reduced fertilizer inputs • Some concern about impact on biodiversity AAAS Annual Meeting

15. Corn stover accounts for about 50% of aboveground crop biomass. In high-yield systems, a portion of the stover could be removed without a reduction in soil quality over time AAAS Annual Meeting

16. Switchgrass: a native American perennial grass AAAS Annual Meeting

17. Challenges to successful large-scale development of the cellulosic ethanol industry • Harvest, handling, storage of huge amounts of biomass • More cost-effective pretreatment and enzyme technologies • Can they utilize multiple feedstock sources? • Improved options for use of co-products • Feedstock for industrial chemicals? • Ensuring protection of environmental quality and natural resources in biomass monocrops • Large-scale commercialization is 7-10 years away; in the meantime, the corn grain ethanol systems builds out to its equilibrium level AAAS Annual Meeting

18. Path to cellulosic ethanol is through a successful build-out of grain-ethanol and oilseed biodiesel systems in next 7 years • $Biofuel Boom busters$ • High consumer food prices due to insufficient grain and oilseed crops for both food and biofuel • In response to high commodity prices • Reduction in water quality from increased fertilizer rates with currently available technologies • Net increases in greenhouse gas emissions rather than a decrease • Expansion of cropping to marginal land resulting in a significant increase in erosion and ecosystem degradation • Expansion of cropping into rain forests, wetlands, grassland savannahs AAAS Annual Meeting

19. Will there be enough corn? • USDA Secretary Mike Johanns (11/16/06): • US farmers should be able to meet booming corn demand • We have companies telling us they are very close in their research to having more drought-resistant, more pest-resistant, more disease-resistant corn hybrids • 4 to 7 million idled CRP acres are viable for corn production • Robert Fraley, Chief Technology Office, Monsanto: National Renewable Energy Conf, St Louis, 10/12/06 • Average corn yields will double within the next 30 years (2.3% per year exponential growth rate) • New biotech hybrids will achieve substantial yield increases under drought and require less N fertilizer • Little published in refereed journals to support these claims; most crop physiologists/agronomists who work on corn yield disagree with this prognosis AAAS Annual Meeting

20. USA Corn Yield Trends, 1966-20051 (embodies tremendous technological innovation) 12000 Transgenic (Bt) insect resistance Soil testing, balanced NPK fertilization, conservation tillage 10000 8000 Double-X to single-X hybrids Reduced N fertilizer & irrigation? GRAIN YIELD (kg ha-1) 6000 y = 112.4 kg/ha-yr 4000 Integrated pest management [1.79 bu/ac-yr] Expansion of irrigated area, increased N fertilizer rates 2 R = 0.80 2000 1965 1970 1975 1980 1985 1990 1995 2000 2005 YEAR AAAS Annual Meeting From: Convergence of Energy and Agriculture, www.cast-science.org

21. Goal: 15 billion gallons from corn grain by 2015, 170% increase • The rate of gain in corn yield will have the greatest impact on USA ethanol production capacity (+60%, annual rate = 5.6%) • Expansion of corn area (+15%, within 2 yrs) Marginal benefits from genetic improvements in grain traits, fermentation enzymes for greater conversion efficiency • Grain starch content increase from 72% to 75% (+6%) • Improve fermentation efficiency from 91% to 97% (+7%) • Total increase from all three ≈ 100% AAAS Annual Meeting

22. USA Corn Yield Trends, 1966-20051 (embodies tremendous technological innovation) 12000 Transgenic (Bt) insect resistance Soil testing, balanced NPK fertilization, conservation tillage 10000 8000 Double-X to single-X hybrids Reduced N fertilizer & irrigation? GRAIN YIELD (kg ha-1) 6000 y = 112.4 kg/ha-yr 4000 Integrated pest management [1.79 bu/ac-yr] Expansion of irrigated area, increased N fertilizer rates 2 R = 0.80 2000 1965 1970 1975 1980 1985 1990 1995 2000 2005 YEAR AAAS Annual Meeting From: Convergence of Energy and Agriculture, www.cast-science.org

23. Changing emphasis of research on sustainable agriculture in a biofuel world • Before biofuels—last 25 years • Organic and alternative agriculture • Food quality • After biofuels—2007 and into foreseeable future • Ecological intensification of major food and biofuel cropping systems • Accelerating yield gains while protecting soil/water quality and contributing to abatement of GHG emissions • Policies that focus expansion of crop land to most suitable areas and avoid extensive loss of native ecosystems AAAS Annual Meeting

24. Nitrogen fertilizer efficiency trend in Nebraska Even with these improvements, average N fertilizer uptake efficiency is only about 40% of applied N with average yields of about 10 Mt per hectare. A 2-fold increase is possible! AAAS Annual Meeting

25. The challenge of applying the optimal N fertilizer rate at high yield levels when yield potential varies yearly with climate and location Current average farm yield AAAS Annual Meeting

26. http://soilfertility.unl.edu/ AAAS Annual Meeting

27. Economic optimum N fertilizer rate increases as the $corn/$N price ratio increases. Algorithm available athttp://soilfertility.unl.edu/ In a biofuel world, farmers will be motivated to use higher N fertilizer rates; without innovative new approaches, N losses will increase substantially AAAS Annual Meeting

28. Reassess and improve technologies previously not considered cost effective • Controlled release “customized” fertilizers • Increased water use efficiency in irrigated systems by moving from furrow/flood to low-pressure pivot, low-pressure pivot, to drip irrigation • Site-specific crop and soil management (large-scale fields); field-specific management for small-scale fields (developing countries) • Dynamic, in-season responsive crop management based on crop simulation models, long-term climate databases, and short-term weather forecasting (N fertilizer, insect and disease control, irrigation scheduling, etc) AAAS Annual Meeting

29. Greater emphasis on field research conducted at the relevant production scale • 30-100 ha fields for large-scale agriculture in developed countries • 1000-5000 m2 field for small-scale agriculture practiced in most developing countries • Small-plot research can give wrong answers • Magnitude and even direction of change • Carbon sequestration predicted by widely used ecosystem models not consistent with field data • N fertilizer use efficiency overestimated in small plots • Must account for spatial variability AAAS Annual Meeting

30. On-farm nitrogen fertilizer efficiency research in the Philippines AAAS Annual Meeting

31. Interactions between crop varieties, nutrient management, and disease epidimeology AAAS Annual Meeting

32. Carbon sequestration and greenhouse gas emissions UNL Carbon Sequestration Program AAAS Annual Meeting

33. Scaling Process Leaf/plot Level Landscape Level Regional UNL Carbon Sequestration Program AAAS Annual Meeting

34. Site classification by fuzzy k-means and the exhaustive sampling scheme at Site 1, Irrigated Continuous Maize • Variables used for fuzzy classification: • soil type, 1965/95 • elevation, 2000 • EC in 0-30 cm, 1999 • soil reflectance, 1993 • SOM, 1999 Sample densities: Site 1,2: 4.5/ha Site 3: 4.0/ha AAAS Annual Meeting UNL Carbon Sequestration Program

35. Key Technological Challenges to Achieve Sustainable Agriculture in a Biofuel World • Eliminate negative environmental impact from cropping systems with yields near yield potential ceiling • Improved nutrient use efficiency and balanced crop nutrition • Digital Agronomy: robust, user-friendly simulation models and geospatial tools for “real-time” crop management to accommodate spatial and temporal variability in soil and climate • Crop genetic improvement (no silver bullets from biotech) • Raise the yield potential ceiling (no quantum leaps, only small incremental improvements possible) • Increased content/quality of fermentables (corn) and oil (soy) • Increase heat and cold tolerance? • Improved drought tolerance? • Biomass crops (switch grass) and crop residues (corn stover, wheat straw) to the rescue over the long-term AAAS Annual Meeting

36. Missing Links • Urgent need for research investment with explicit focus on both raising crop yields and protecting environmental quality and conserving natural resources • Use subsidies/incentives to foster “green” life-cycle biofuel production practices • Policies that direct expansion of biofuel crop area to areas with adequate soil quality to support intensified agriculture in a sustainable fashion; avoid marginal land and repositories of unique wildlife and biodiversity • If there is a measurable increase in environmental degradation, public support and favorable tax incentives for biofuels will disappear! AAAS Annual Meeting

37. Citations • Cassman KG. 1999. Ecological intensification of cereal production systems: Yield potential, soil quality, and precision agriculture. Proc. National Acad. Sci. (USA) 96: 5952-5959. • Duvick, DN and KG Cassman. 1999. Post-green-revolution trends in yield potential of temperate maize in the north-central United States. Crop Sci. 39:1622-1630. • Cassman KG, Dobermann A, and Walters D. 2002. Agroecosystems, nitrogen-use efficiency, and nitrogen management. AMBIO 31:132-140. • Cassman, K.G., Dobermann, A., Walters, D.T., Yang, H. 2003. Meeting cereal demand while protecting natural resources and improving environmental quality. Annu. Rev. Environ. Resour. 28: 315-358 • Cassman, K.G., Eidman, VT., and Simpson, G. 2006. Convergence of energy and agriculture: Implications for research and policy. Council for Agricultural Science and Technology (CAST). www.cast-science.org • Haishun Y., Dobermann A., Cassman K.G., and Walters D.T. 2006. Features, Applications, and Limitations of the Hybrid-Maize Simulation Model. Agron. J. 98:737-748 • Hybrid-Maize Simulation Model: www.hyridmaize.unl.edu • University of Nebraska N Fertilizer Recommendations for Corn. http://soilfertility.unl.edu/ • Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. 2002. Agricultural sustainability and intensive production practices. Nature 418: 671-677 AAAS Annual Meeting

38. THANK YOU! AAAS Annual Meeting