Perennial possibilities for increasing food and ecosystem security


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Perennial possibilities for increasing food and ecosystem security

  1. 1. Perennial possibilities forincreasing food andecosystem securityJerry GloverUSAIDWashington,
  2. 2. “[agriculture]…largest threat to biodiversity andecosystem function of any single humanactivity.”Millennium Ecosystem Assessment (2005)
  3. 3. “[agriculture]…one of the most importantdrivers of…habitat change, climate change,water use, and toxic emissions.”UN Environment Program Report (2010)
  4. 4. (CIMMYT, 2010)
  5. 5. (CIMMYT, 2010)
  6. 6. Model systems:Perennial grasslands harvested every yearfor over 75 years; only atmospheric inputs
  7. 7. Model systems:Perennial grasslands harvested every yearfor over 75 years; only atmospheric inputsHow do they compare to high-input annualcereal production?
  8. 8. • Yields• Carbon & nitrogen• Ecosystem processes
  9. 9. Glover et al., 2010. Harvestedperennial grasslands provideecological benchmarks foragricultural sustainability.DuPont et al., 2010. No-tillageconversion of harvestedperennial grassland to annualcroplandCulman et al., 2010. Long-termimpacts of high-input annualcropping and unfertilizedperennial grass productionAEE, Vol. 137, Issues 1-2, 2010
  10. 10. PerennialgrassAnnualwheat p-valueHarvestednitrogen (kg ha-1)47.9 47.2 0.909Farmers are removing roughly equal amounts ofnitrogen from both systems; annual crop fieldsreceive over 60 kg ha-1 yr-1 more nitrogen
  11. 11. PerennialgrassAnnualwheatp-valueTotal carbon 182.2 138.8 0.027Total nitrogen 15.4 11.7 0.013Soil quality (0 – 1.0 m; Mg ha-1):
  12. 12. perennialwheatRoot C of perennial and wheat fields
  13. 13. Differences not simply artifacts of obsoletefarming practices such as poor tillage &fertilizer practices
  14. 14. Differences not simply artifacts of obsoletefarming practices such as poor tillage &fertilizer practicesDuPont et al: No-tillage conversion of nativegrassland using best-practices•reductions in active carbon stocks•reductions in water stable aggregates•Negative impacts on soil food webs
  15. 15. Conservation Ag: low tillage, rotations, residue maintenance
  16. 16. Additional examples•Sustained harvests of unfertilized perennialgrasslands (USDA county yield data; Shortridge, 1973;Jenkinson et al., 1994, Silvertown et al., 1994)•SOC and total soil N not reduced afterdecades of unfertilized grassland harvests(Jenkinson et al., 2004; Mikhailova et al., 2000, Mikhailova andPost, 2006)
  17. 17. ( mmPhoto credit: Jim Richardson
  18. 18. ( mmPhoto credit: Jim RichardsonSmall-scale processes »» Large-scale landscape healthminutes and millimeters
  19. 19. Humans don’t eat hay
  20. 20. Global cropland (% of total area)Fruits &vegetables7%Roots &tubers 4%Tree crops2%Forages11%Other3%Fiber3%Cereals, oilseeds, legumes68%From Monfreda et al., 2008
  21. 21. Global cropland (% of total area)Cereals, oilseeds, legumes68%From Monfreda et al., 2008These are allannual crops
  22. 22. Global cropland (% of total area)Cereals, oilseeds, legumes68%From Monfreda et al., 2008Provide for more than70% of our calories needs
  23. 23. Perennial grain cropsSorghumMaizeLegumesRiceWheatgrass & wheatSunflowersOilseeds
  24. 24. Washington State University:Texas A&M:The Land Institute: perennialsorghum, sunflower, wheat, +.Yunnan Academy of AgriculturalSciencesCSIRO: perennial wheatGlobal perennial grain programsMich. State Univ.: perennialwheat & wheatgrassSwedish University Ag SciUniversity of ManitobaCatedra de CultivosIndustriales: Lesquerella(mustard family)Nepal: perennial wheatCornell: perennial maize
  25. 25. Domestication:Intermediate wheatgrass
  26. 26. Wild1 -2cycles3cycles
  27. 27. 1 mDomestication:Intermediate wheatgrass
  28. 28. 1 mDomestication:Intermediate wheatgrass
  29. 29. XWide hybridization:perennial wheat
  30. 30. wheat/wheatgrass//wheatwheat/wheatgrass//wheatgrasswheatgrass
  31. 31. Dr. Dhruba ThapaNepal Agricultural Research CouncilKhumaltar Laitpur, NepalHigh altitude perennial wheat in western Nepal“…increase food & forage securitysignificantly in the region.”
  32. 32. “…minimize theworkload of farmers,especially of women inthe remote areas.”
  33. 33. Deeper roots: “…more stablegrain and biomass yields”
  34. 34. Deeper roots: “…higheruptake of selenium, zinc,iron and other minerals.”
  35. 35. “…some of the 25 lines appearhighly resistant to yellow rust.”
  36. 36. Perennial Concerns• Can perennials produce as muchgrain?• Aren’t perennials more vulnerable topests and disease?• Will perennials become weeds?• How long will it take?
  37. 37. Perennial Concerns Yield• Perennials have higher yield potential• Consider within context of whole system• Multifunctionality is key
  38. 38. Perennial Concerns Pests and disease• Increases potential to diversify rotations,intercrops, relay systems• Wide crosses introduce new pathways forresistance
  39. 39. Perennial Concerns Weediness• Unlike perennial forages, perennial grains aredesigned to put their energy into seeds notvegetation
  40. 40. Perennial Concerns Time• Farmers already use some perennial grainlegumes—pigeon peas• Perennial sorghum & rice: field trials within 5years; farmer-ready within 15 years• Perennial wheat: farmer-ready in 20 years
  41. 41. Perennial Possibilities We can transform our farms tofunction more like natural ecosystems Perennial grain crops are the next step Mitigation: If agricultural soils can beused to offset industrial emissions ofGHGs, perennial crops will be key Adaptation: Perennial crops are moreresilient
  42. 42. Jerry GloverUSAIDWashington,