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

2. Argolis, Greece 7000 B.C.—Simple agriculture begins7000 B.C.—Simple agriculture begins 4000 B.C.—Agriculture intensifies4000 B.C.—Agriculture intensifies 3000 B.C.—Major civilization3000 B.C.—Major civilization 2500 B.C.—Civilization collapses2500 B.C.—Civilization collapses 1500 B.C.—New civilization1500 B.C.—New civilization 200 B.C.—Civilization collapses200 B.C.—Civilization collapses 900 A.D.—New civilization900 A.D.—New civilization 1200 A.D.—Civilization collapses1200 A.D.—Civilization collapses SOIL EROSION Importing half of their food

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

8. 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” Diverse ag Tobacco Cotton

9. Erosion: a familiar face in Missouri

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) Grass for cellulosic ethanol—thumbs up!

11. 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)Corn stover removal? (cellulosic ethanol) Continuous soybean? (biodiesel)Continuous soybean? (biodiesel)

12. Erosion and C SystemC No-till corn0.03 No-till soybean0.07 Corn silage 10% cover0.22 Corn silage spring plow0.43 Corn Stalk Ethanol 7-15X Higher

13. 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

14. 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)

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

16. 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)

17. 180 N at planting 153 N sidedress V7.5 Nitrogen timing in 2009: in-season N kicks butt again + 68 bu/acre

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

19. Diagnosing where to put more N Predictor % of variability in N need explained Yield2 to 20 Soil nitrate17 to 25 Soil N quick tests0 to 18 Soil conductivity8 Corn color53 to 77

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

21. 55 on-farm sensor N demonstrations 2004-2008

22. Sensor-N impact on energy balance of ethanol

23. Streaky N applications are very inefficient

24. 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)?

25. 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