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Sustainability & Energy Crops

Sustainability & Energy Crops. Peter Scharf University of Missouri Plant Sciences. SOIL EROSION. SOIL EROSION. SOIL EROSION. Importing half of their food. Argolis, Greece. 7000 B.C.—Simple agriculture begins 4000 B.C.—Agriculture intensifies 3000 B.C.—Major civilization

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Sustainability & Energy Crops

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  1. Sustainability & Energy Crops Peter Scharf University of Missouri Plant Sciences

  2. SOIL EROSION SOIL EROSION SOIL EROSION Importing half of their food Argolis, Greece • 7000 B.C.—Simple agriculture begins • 4000 B.C.—Agriculture intensifies • 3000 B.C.—Major civilization • 2500 B.C.—Civilization collapses • 1500 B.C.—New civilization • 200 B.C.—Civilization collapses • 900 A.D.—New civilization • 1200 A.D.—Civilization collapses

  3. Argolis, Greece • Q: How do they know that erosion occurred? • A: Find topsoil deposits ‘downstream’ • Q: How do they know it caused civilizations to fail? • A: Erosion peaks = civilization peaks • Q: How do they know it was caused by agriculture? • A: Written records: Plow 3 times/year • Q: How do they know it wasn’t caused by weather? • A: Within-region differences in erosion/collapse schedules

  4. What is ‘sustainability’? • Can continue the same practices for a long period of time • Outputs stable • Inputs stable • Off-site effects acceptable

  5. Closer to home

  6. Piedmont, Virginia Tell me what you see

  7. Diverse ag Tobacco Cotton Closer to home • Used to be a major ag region • “Soil erosion was rampant from early times” • “Most old agricultural fields are now in pine forests”

  8. Erosion: a familiar face in Missouri

  9. Biofuels: potential impact on erosion • Pressure to: • Put more land into crops (marginal) • Increase cropping intensity • More continuous corn • Reduced erosion? • Corn stover removal? (cellulosic ethanol) • Continuous soybean? (biodiesel) • Grass for cellulosic ethanol—thumbs up!

  10. Biofuels: potential impact on erosion • Pressure to: • Put more land into crops (marginal) • Increase cropping intensity • More continuous corn • Reduced erosion? • Corn stover removal? (cellulosic ethanol) • Continuous soybean? (biodiesel)

  11. Corn Stalk Ethanol 7-15X Higher Erosion and C

  12. What is ‘sustainability’? • Can continue the same practices for a long period of time • Outputs stable? • Maintain topsoil • Maintain nutrients • Inputs stable? • Continued availability of energy inputs? • Off-site effects acceptable? • N, P, sediment, atrazine in water

  13. Energy inputs & balance • Nitrogen fertilizer is by far the biggest single energy input • Efficient N use will be crucial to a positive energy balance • In-season N application timing • Diagnose correct rate (varies across the field) • Avoid streaky applications (equipment problems)

  14. Energy budget for corn production Data from Shapouri et al. 2002, nine state average

  15. Energy inputs & balance • Nitrogen fertilizer is by far the biggest single energy input • Efficient N use will be crucial to a positive energy balance • In-season N application timing • Diagnose correct rate (varies across the field) • Avoid streaky applications (equipment problems)

  16. Nitrogen timing in 2009:in-season N kicks butt again + 68 bu/acre 153 N sidedress V7.5 180 N at planting

  17. Crop N need is variable within fields What happens if you apply 150 lb N/acre to this field?

  18. Diagnosing where to put more N

  19. Controller runs ball valve to change fertilizer rate Computer in cab reads sensors, calculates N rate, directs controller sensors Crop sensors for N rate diagnosis

  20. 55 on-farm sensor N demonstrations 2004-2008

  21. Sensor-N impact on energy balance of ethanol

  22. Streaky N applications are very inefficient

  23. SUMMARY: Sustainability & Energy Crops • Soil erosion is the biggest threat to sustainability • Only major historical reason for agricultural failure and collapse • Missouri is an erodibility champion • Grass fine, corn stalks maybe not • Energy input is another major obstacle • Efficient N use is crucial (HIGH energy input) • Transport of low-density crops (hay)?

  24. SUMMARY: Sustainability & Energy Crops • Off-site effects and sustainability • Judgement call • N, P, sediment, atrazine • Much more of an issue with corn grain and stover than with grass and wood

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