Science and Sustainability in U.S. AgricultureKenneth G. CassmanDirector, Nebraska Center for Energy Science Research (www.ncesr.unl.edu)University of Nebraska

AAAS Annual Meeting

Topics U.S. and global agriculture undergoing a biofuel revolutionThe first phase based on food crop conversion to biofuels plays out within next 10 yearsIs causing an abrupt increase in the value of crop commodities and arable landFrom food surplus to food scarcity in two years!Impact on focus of agricultural sustainabilityChanges in scientific emphasis and funding prioritiesCritical need to bet on winners (higher batting average): hype to reality ratio

AAAS Annual Meeting

Global Importance of U.S. Agriculture Largest global exporter of staple food and oilseed crops60% of maize*44% of soybean*36% of rice*27% of wheat**2004Largest humanitarian food donor56% of global total for cereals (2002 & 2003)

AAAS Annual Meeting

Challenges to Sustainable Agriculture Population growth and rapid economic development in developing countriesHigher incomes, richer diets with more livestock productsLimited arable land suitable for crop productionClimate change, especially warmer temperatures and greater variabilityRising prices for petroleum and other forms of energyMakes use of food crops for biofuel production a profitable proposition

AAAS Annual Meeting

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 levelsCongress passed the 2005 Energy Policy Act mandating a 7.5 billion gallon Renewable Fuel Standard by 2012Large venture capital flows to the U.S. biofuel industryEthanol production capacity will reach 11.6 billion gallons by end of 2008Other countries too (Brazil, Indonesia, Europe)Corn and other biofuel crop prices have risen dramatically

AAAS Annual Meeting

Energy Consumption and Income are Linked5 billion low-income people in countries with rapid economic growth rates

AAAS Annual Meeting

Oil Consumption Much Great Than Oil Discovery

AAAS Annual Meeting

Compelling Biofuel BenefitsDecreased reliance on imported petroleumNet reduction in greenhouse gas emissionsIncreased agricultural commodity prices and farm incomeReduction in need for crop subsidiesRural jobs and economic development

AAAS Annual Meeting

Convergence of energy & agricultureCorn price is now being determined by the value of corn grain as a feedstock for biofuelWhile 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

USA Ethanol Production Capacity12 billion gal by 200915 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

Expansion of Biofuel Production is a Global PhenomenonBrazil: tremendous capacity to increase ethanol production from sugarcane, biodiesel from soybean and perhaps oil palmIndonesia/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

Actual global trends in cereal harvest areaSource: FAOSTAT1981: 727 million ha 2003: 666 million ha

AAAS Annual Meeting

AAAS Annual Meeting

The Promise of Cellulosic Ethanol Mostly avoids direct food vs fuel competitionIndirect competition for landLarge amount of cellulosic biomass feedstock could support substantial expansion of ethanol production capacityMay have greater positive environmental impact than corn grain ethanol: larger reduction in GHG emissions, better protects soil quality, reduced fertilizer inputsSome concern about impact on biodiversity

AAAS Annual Meeting

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

Switchgrass: a native American perennial grass

AAAS Annual Meeting

Challenges to successful large-scale development of the cellulosic ethanol industryHarvest, handling, storage of huge amounts of biomassMore cost-effective pretreatment and enzyme technologiesCan they utilize multiple feedstock sources?Improved options for use of co-productsFeedstock for industrial chemicals?Ensuring protection of environmental quality and natural resources in biomass monocropsLarge-scale commercialization is 7-10 years away; in the meantime, the corn grain ethanol systems builds out to its equilibrium level

AAAS Annual Meeting

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 biofuelIn response to high commodity pricesReduction in water quality from increased fertilizer rates with currently available technologiesNet increases in greenhouse gas emissions rather than a decreaseExpansion of cropping to marginal land resulting in a significant increase in erosion and ecosystem degradationExpansion of cropping into rain forests, wetlands, grassland savannahs

AAAS Annual Meeting

Will there be enough corn?USDA Secretary Mike Johanns (11/16/06):US farmers should be able to meet booming corn demandWe 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 productionRobert 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 fertilizerLittle published in refereed journals to support these claims; most crop physiologists/agronomists who work on corn yield disagree with this prognosis

AAAS Annual Meeting

From: Convergence of Energy and Agriculture, www.cast-science.org

AAAS Annual Meeting

Goal: 15 billion gallons from corn grain by 2015, 170% increaseThe 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 efficiencyGrain 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

From: Convergence of Energy and Agriculture, www.cast-science.org

AAAS Annual Meeting

Changing emphasis of research on sustainable agriculture in a biofuel worldBefore biofuelslast 25 yearsOrganic and alternative agricultureFood quality

After biofuels2007 and into foreseeable futureEcological intensification of major food and biofuel cropping systemsAccelerating yield gains while protecting soil/water quality and contributing to abatement of GHG emissionsPolicies that focus expansion of crop land to most suitable areas and avoid extensive loss of native ecosystems

AAAS Annual Meeting

Nitrogen fertilizer efficiency trend in NebraskaEven 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

Chart2

1960

1961

1962

1963

1964

40.9090909091

43.2246998285

35.026296018

28.4441732764

37.6478067387

29.4209215442

34.1199226306

43.6756049706

38.7311968607

30.6037473976

40.5681818182

34.0432294978

42.1122994652

44.8569612206

41.9513607412

43.7355371901

41.9513607412

43.4482758621

34.7986191024

1984

48.2296650718

51.9922630561

55.1515151515

49.2061459667

47.3981191223

50.5113636364

53.4545454545

56.4304812834

43.7967914439

56.8606932636

45.7357750164

57.676056338

50.0662251656

65.3901216893

56.0627400768

48.5950413223

63.7809917355

2002

64.3216783217

2004

63.9130434783

2006

Partial Factor Productivity (kg grain kg N-1)

Summary

Nebraska Corn Yield and N Use

Richard B. Ferguson - University of Nebraska

Data from Nebraska Agricultural Statistics

Statewide average corn yield for grain and surveyed average N rate for corn - dryland & irrigated

Number of fields surveyed for N rate varies annually; ranges from 193 in 1986 to 690 in 1994

Nebraska statewide meansSurvey Based

Corn YieldPlantedPlantedHarvestedHarvestedProductionProductionPriceValueN RateN Use EfficiencyPFPNPFPNNational N Price - AmmoniaRatioRatioN$/buN$/buN $/acre

Yearbu/acreMg/haAcreshaAcresha1000 buMg$/bu$lb/acrekg N/halb N/bukg N/kg Ybu/lb Nkg grain/kg N$/ton (April)$/lb N$ bu/$ lb N$ kg grain/$ kg N(@ nat'l N price)(@ $0.15/lb N)(@ nat'l N price

1955201.2667142719477519349550024279921.44137520000166.000.10114.2270.254

1956241.51262442529403716359487024119751.36129023200161.000.09813.8530.247

1957472.961499520234718191121938755776951.09239131830152.000.09311.7610.210

1958513.213564422865415219327616570212191.12309304800150.000.09112.2450.219

1959493.087688627896558265631806380864341.03327604890147.000.09011.4910.205

1960513.213688627896538264833343884773280.98326769240141.000.08611.3990.204

1961523.276557822595296214527539270015661.11305685120142.000.08712.8200.229

1962613.843535521695031203830437677384551.11337857360134.000.08213.5850.243

1963573.591540921915031203828676772907641.08309708360128.000.07813.8380.247

1964543.402416516873793153620482252073951.16237593520126.000.07715.0980.270

1965704.41387315693565144424955063445591.1729197350098107.81.400.02440.7140.91122.000.07415.7280.2810.1040.2110.21

1966805.04441517884100166132800083390721.19390320000106116.61.330.02310.7543.22119.000.07316.4000.2930.0960.2010.19

1967744.662498920214510182733374084850061.05350427000121133.11.640.02850.6135.03113.000.06915.2390.2720.1130.2513.63

1968744.662483919604239171731368679751531.09341917740149163.92.010.03520.5028.4491.000.05519.6440.3510.1120.3016.65

1969945.9225040204146201871434280110411351.09473365200143157.31.520.02660.6637.6576.000.04623.5210.4200.0700.2310.08

1970754.725544322044828195536692893287771.25458660000146160.61.950.03400.5129.4275.000.04627.3330.4880.0890.2913.00

1971845.2925919239753002147450500114535121.11500055000141155.11.680.02930.6034.1279.000.04823.0430.4110.0810.2511.40

19721066.6785680230051352080534040135774331.53817081200139152.91.310.02290.7643.6880.000.04931.3650.5600.0640.208.89

1973945.9226480262459002390554600141001502.411336586000139152.91.480.02580.6838.7388.000.05444.9140.8020.0790.2211.03

1974704.416800275457002309399000101441762.921165080000131144.11.870.03270.5330.60183.000.11226.1680.4670.2090.2827.36

1975855.3556500263359202398503200127933572.4812479360001201321.410.02460.7140.57265.000.16215.3480.2740.2280.2127.37

1976855.3556850277461002471518500131823442.061068110000143157.31.680.02940.5934.04191.000.11617.6880.3160.1960.2528.02

19771006.37150289665502653648450164861931.971277446500136149.61.360.02370.7442.11188.000.11517.1850.3070.1560.2021.20

19781127.0567250293667502734762750193921562.221693305000143157.31.280.02230.7844.86177.000.10820.5690.3670.1380.1919.71

19791157.2457600307871502896822250209048842.421989845000157172.71.370.02380.7341.95171.000.10423.2090.4140.1420.2022.35

1980845.2927800315971002876603500153433843.0418346400001101211.310.02290.7643.74229.000.14021.7710.3890.1830.2020.11

19811157.2457400299768802786791200201154692.511985912000157172.71.370.02380.7341.95243.000.14816.9400.3030.2020.2031.76

19821106.937300295768002754748000190171522.822109360000145159.51.320.02300.7643.45255.000.15518.1360.3240.2050.2029.72

1983966.0485300214748501964470450119607213.131472508500158173.81.650.02870.6134.80237.000.14521.6590.3870.2380.2537.58

19841167.3087400299769502815806200204968292.582079996000275.000.16815.3860.275

19851288.0647800315974503017953600242443262.222116992000152167.21.190.02070.8448.23255.000.15514.2780.2550.1850.1828.07

19861288.0647300295770002835896000227799041.521361920000141155.11.100.01920.9151.99225.000.13711.0790.1980.1510.1721.31

19871308.196500263362002511812200206493731.961591912000135148.51.040.01810.9655.15187.000.11417.1890.3070.1180.1615.99

19881227.6866900279566002673818400208070022.482029632000142156.21.160.02030.8649.21208.000.12719.5540.3490.1480.1720.96

19891207.567400299770002835847000215341282.31948100000145159.51.210.02110.8347.40224.000.13716.8390.3010.1650.1823.93

19901278.0017700311973002957934400237561862.282130432000144158.41.130.01980.8850.51199.000.12118.7900.3360.1380.1719.81

19911267.9388200332178003159990600251850142.342318004000135148.51.070.01870.9353.45210.000.12818.2740.3260.1370.1618.52

19921348.44283003362790032001066500271146962.092228985000136149.61.010.01770.9956.43208.000.12716.4790.2940.1290.1517.51

19931046.5528000324075503058785200199629252.521978704000136149.61.310.02280.7643.80213.000.13019.4030.3460.1700.2023.10

19941388.69486003483825033411146750291549722.332671927500139152.91.010.01760.9956.86243.000.14815.7250.2810.1490.1520.74

19951116.9938000324077003119854700217298933.222752134000139152.91.250.02190.8045.74330.000.20116.0020.2860.2520.1935.02

19961439.00985003443825033411179750299939642.643114540000142156.20.990.01731.0157.68303.000.18514.2890.2550.1830.1526.05

19971328.31689003605860034831135200288613252.322633664000151166.11.140.02000.8750.07303.000.18512.5570.2240.2110.1731.91

19981459.13588003564855034631239750315194041.882330730000127139.70.880.01531.1465.39253.000.15412.1870.2180.1350.1317.16

19991398.75786003483830033621153700293316691.752018975000142156.21.020.01780.9856.06211.000.12913.6020.2430.1310.1518.66

20001267.93885003443805032601014300257875631.91927170000148.5163.351.180.02060.8548.60227.000.13813.7270.2450.1630.1824.23

20011479.26181003281775031391139250289642921.942210145000132145.20.900.01571.1163.78399.000.2437.9740.1420.2180.1328.84

20021288.0648400340273502977940800239188992.322182656000250.000.15215.2190.272

20031469.19881003281770031191124200285816612.3926868380001301430.890.01551.1264.32374.000.22810.4800.1870.2030.1326.40

200416610.45882503341795032201319700335520532.022665794000379.000.2318.7410.156

20051549.70285003443825033411270500323011921.852350425000138151.80.900.01561.1263.91416.000.2547.2930.1300.22731.37

20061529.57681003281775031391178000299494722.052414900000521.000.3186.4530.115

Mean137.8151.61.30.00.8198.10.116.90.20.221.3

Median1401541.2922390110.02256290340.77396133281990.121341463415.72510288070.15018671710.196153846221.0824534186

At constant fertilizer dollars, the greatest cost per acre for N fertilizer was 1970 at $43/acre; the lowest cost was 1996, 1994 and other years at $21/acre.

At constant fertilizer dollars, the greatest cost per bushel for N fertilizer was 1968 at $0.30/bu; the lowest cost was 1996, 1994 and 1992 at $0.15/bu.

Source: Nebraska State Agricultural Statistics Service

&L&D&F

Summary

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Lb N/bu

Nitrogen Use Efficiency (lb N/bu corn)

SigmaPlot Data

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

$ bu/$ lb N

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

N Investment ($/acre)

NSAS-Corn

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Partial Factor Productivity (kg Grain kg N-1)

YearYld bu/aYld Mg/haPl AcresPl haHarvest AcresHarvest haProd 1000buProd MgPrice $/buValue $NR lb/aNR kg/haNUE lbN/buNUE kgN/MgPFPN bu/lbNNat N $/tonNat N $/lb$ bu/$ lb NN$/buN$/bu15N $/acre

19552067142719477519349550024279921.44137520000

19562462442529403716359487024119751.36129023200

195747499520234718191121938755776951.09239131830

195851564422865415219327616570212191.12309304800

195949688627896558265631806380864341.03327604890

196051688627896538264833343884773280.98326769240141.000.08611.399

196152557822595296214527539270015661.11305685120142.000.08712.820

196261535521695031203830437677384551.11337857360134.000.08213.585

196357540921915031203828676772907641.08309708360128.000.07813.838

196454416516873793153620482252073951.16237593520126.000.07715.098

1965704.41387315693565144424955063445591.1729197350098107.81.4024.440.71122.000.07415.7280.1040.2110.21

1966805.04441517884100166132800083390721.19390320000106116.61.3323.130.75119.000.07316.4000.0960.2010.19

1967744.662498920214510182733374084850061.05350427000121133.11.6428.550.61113.000.06915.2390.1130.2513.63

1968744.662483919604239171731368679751531.09341917740149163.92.0135.160.5091.000.05519.6440.1120.3016.65

1969945.9225040204146201871434280110411351.09473365200143157.31.5226.560.6676.000.04623.5210.0700.2310.08

1970754.725544322044828195536692893287771.25458660000146160.61.9533.990.5175.000.04627.3330.0890.2913.00

1971845.2925919239753002147450500114535121.11500055000141155.11.6829.310.6079.000.04823.0430.0810.2511.40

19721066.6785680230051352080534040135774331.53817081200139152.91.3122.900.7680.000.04931.3650.0640.208.89

1973945.9226480262459002390554600141001502.411336586000139152.91.4825.820.6888.000.05444.9140.0790.2211.03

1974704.416800275457002309399000101441762.921165080000131144.11.8732.680.53183.000.11226.1680.2090.2827.36

1975855.3556500263359202398503200127933572.4812479360001201321.4124.650.71265.000.16215.3480.2280.2127.37

1976855.3556850277461002471518500131823442.061068110000143157.31.6829.370.59191.000.11617.6880.1960.2528.02

19771006.37150289665502653648450164861931.971277446500136149.61.3623.750.74188.000.11517.1850.1560.2021.20

19781127.0567250293667502734762750193921562.221693305000143157.31.2822.290.78177.000.10820.5690.1380.1919.71

19791157.2457600307871502896822250209048842.421989845000157172.71.3723.840.73171.000.10423.2090.1420.2022.35

1980845.2927800315971002876603500153433843.0418346400001101211.3122.860.76229.000.14021.7710.1830.2020.11

19811157.2457400299768802786791200201154692.511985912000157172.71.3723.840.73243.000.14816.9400.2020.2031.76

19821106.937300295768002754748000190171522.822109360000145159.51.3223.020.76255.000.15518.1360.2050.2029.72

1983966.0485300214748501964470450119607213.131472508500158173.81.6528.740.61237.000.14521.6590.2380.2537.58

19841167.3087400299769502815806200204968292.582079996000275.000.16815.386

19851288.0647800315974503017953600242443262.222116992000152167.21.1920.730.84255.000.15514.2780.1850.1828.07

19861288.0647300295770002835896000227799041.521361920000141155.11.1019.230.91225.000.13711.0790.1510.1721.31

19871308.196500263362002511812200206493731.961591912000135148.51.0418.130.96187.000.11417.1890.1180.1615.99

19881227.6866900279566002673818400208070022.482029632000142156.21.1620.320.86208.000.12719.5540.1480.1720.96

19891207.567400299770002835847000215341282.31948100000145159.51.2121.100.83224.000.13716.8390.1650.1823.93

19901278.0017700311973002957934400237561862.282130432000144158.41.1319.800.88199.000.12118.7900.1380.1719.81

19911267.9388200332178003159990600251850142.342318004000135148.51.0718.710.93210.000.12818.2740.1370.1618.52

19921348.44283003362790032001066500271146962.092228985000136149.61.0117.720.99208.000.12716.4790.1290.1517.51

19931046.5528000324075503058785200199629252.521978704000136149.61.3122.830.76213.000.13019.4030.1700.2023.10

19941388.69486003483825033411146750291549722.332671927500139152.91.0117.590.99243.000.14815.7250.1490.1520.74

19951116.9938000324077003119854700217298933.222752134000139152.91.2521.860.80330.000.20116.0020.2520.1935.02

19961439.00985003443825033411179750299939642.643114540000142156.20.9917.341.01303.000.18514.2890.1830.1526.05

19971328.31689003605860034831135200288613252.322633664000151166.11.1419.970.87303.000.18512.5570.2110.1731.91

19981459.13588003564855034631239750315194041.882330730000127139.70.8815.291.14253.000.15412.1870.1350.1317.16

19991398.75786003483830033621153700293316691.752018975000142156.21.0217.840.98211.000.12913.6020.1310.1518.66

20001267.93885003443805032601014300257875631.91927170000148.5163.351.1820.580.85227.000.13813.7270.1630.1824.23

20011479.26181003281775031391139250289642921.942210145000132145.20.9015.681.11399.000.2437.9740.2180.1328.84

20021288.0648400340273502977940800239188992.322182656000250.000.15215.219

20031469.19881003281770031191124200285816612.3926868380001301430.8915.551.12374.000.22810.4800.2030.1326.40

200416610.45882503341795032201319700335520531.952573415000379.000.2318.438

2005416.000.254

cmdty_descyearstPLANTEDHARVESTDYIELDPRODUCTNPRICEVALUE

CommodityYearStatePlantedHarvestedYieldProductionPrice per UnitValue of production

acres - thousandacres - thousandbushel1000 bushelsdols / bu1000 dollars

Corn For Grain1955NE6714477520955001.44137520

Corn For Grain1956NE6244403723.5948701.36129023

Corn For Grain1957NE4995471846.52193871.09239132

Corn For Grain1958NE56445415512761651.12309305

Corn For Grain1959NE6886655848.53180631.03327605

Corn For Grain1960NE68866538513334380.98326769

Corn For Grain1961NE55785296522753921.11305685

Corn For Grain1962NE5355503160.53043761.11337857

Corn For Grain1963NE54095031572867671.08309708

Corn For Grain1964NE41653793542048221.16237594

Corn For Grain1965NE38733565702495501.17291974

Corn For Grain1966NE44154100803280001.19390320

Corn For Grain1967NE49894510743337401.05350427

Corn For Grain1968NE48394239743136861.09341918

Corn For Grain1969NE50404620944342801.09473365

Corn For Grain1970NE54434828763669281.25458660

Corn For Grain1971NE59195300854505001.11500055

Corn For Grain1972NE568051351045340401.53817081

Corn For Grain1973NE64805900945546002.411336586

Corn For Grain1974NE68005700703990002.921165080

Corn For Grain1975NE65005920855032002.481247936

Corn For Grain1976NE68506100855185002.061068110

Corn For Grain1977NE71506550996484501.971277447

Corn For Grain1978NE725067501137627502.221693305

Corn For Grain1979NE760071501158222502.421989845

Corn For Grain1980NE78007100856035003.041834640

Corn For Grain1981NE740068801157912002.511985912

Corn For Grain1982NE730068001107480002.822109360

Corn For Grain1983NE53004850974704503.131472509

Corn For Grain1984NE740069501168062002.582079996

Corn For Grain1985NE780074501289536002.222116992

Corn For Grain1986NE730070001288960001.521361920

Corn For Grain1987NE650062001318122001.961591912

Corn For Grain1988NE690066001248184002.482029632

Corn For Grain1989NE740070001218470002.31948100

Corn For Grain1990NE770073001289344002.282130432

Corn For Grain1991NE820078001279906002.342318004

Corn For Grain1992NE8300790013510665002.092228985

Corn For Grain1993NE800075501047852002.521978704

Corn For Grain1994NE8600825013911467502.332671928

Corn For Grain1995NE800077001118547003.222752134

Corn For Grain1996NE8500825014311797502.643114540

Corn For Grain1997NE8900860013211352002.322633664

Corn For Grain1998NE8800855014512397501.882330730

Corn For Grain1999NE8600830013911537001.752018975

Corn For Grain2000NE8500805012610143001.91927170

Corn For Grain2001NE8100775014711392501.942210145

Corn For Grain2002NE840073501289408002.322182656

Corn For Grain2003NE8100770014611242002.392686838

Corn For Grain2004NE8250795016613197001.952573415

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

http://soilfertility.unl.edu/

AAAS Annual Meeting

AAAS Annual Meeting

Reassess and improve technologies previously not considered cost effectiveControlled release customized fertilizersIncreased water use efficiency in irrigated systems by moving from furrow/flood to low-pressure pivot, low-pressure pivot, to drip irrigationSite-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

Greater emphasis on field research conducted at the relevant production scale30-100 ha fields for large-scale agriculture in developed countries1000-5000 m2 field for small-scale agriculture practiced in most developing countriesSmall-plot research can give wrong answersMagnitude and even direction of changeCarbon sequestration predicted by widely used ecosystem models not consistent with field dataN fertilizer use efficiency overestimated in small plotsMust account for spatial variability

AAAS Annual Meeting

On-farm nitrogen fertilizer efficiency research in the Philippines

AAAS Annual Meeting

Interactions between crop varieties, nutrient management, and disease epidimeology

AAAS Annual Meeting

Carbon sequestration and greenhouse gas emissionsUNL Carbon Sequestration Program

AAAS Annual Meeting

AAAS Annual Meeting

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

AAAS Annual Meeting

Key Technological Challenges to Achieve Sustainable Agriculture in a Biofuel WorldEliminate negative environmental impact from cropping systems with yields near yield potential ceilingImproved 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 climateCrop 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

Missing LinksUrgent need for research investment with explicit focus on both raising crop yields and protecting environmental quality and conserving natural resourcesUse subsidies/incentives to foster green life-cycle biofuel production practicesPolicies 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 biodiversityIf there is a measurable increase in environmental degradation, public support and favorable tax incentives for biofuels will disappear!

AAAS Annual Meeting

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.orgHaishun 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.eduUniversity 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

THANK YOU!

AAAS Annual Meeting