1. Perennial possibilities for
increasing food and
ecosystem security
Jerry Glover
USAID
Washington, DC
jglover@usaid.gov

2. “[agriculture]…largest threat to biodiversity and
ecosystem function of any single human
activity.”
Millennium Ecosystem Assessment (2005)

3. “[agriculture]…one of the most important
drivers of…habitat change, climate change,
water use, and toxic emissions.”
UN Environment Program Report (2010)

4. (CIMMYT, 2010)

5. (CIMMYT, 2010)

7. Model systems:
Perennial grasslands harvested every year
for over 75 years; only atmospheric inputs

8. Model systems:
Perennial grasslands harvested every year
for over 75 years; only atmospheric inputs
How do they compare to high-input annual
cereal production?

9. • Yields
• Carbon & nitrogen
• Ecosystem processes

10. Glover et al., 2010. Harvested
perennial grasslands provide
ecological benchmarks for
agricultural sustainability.
DuPont et al., 2010. No-tillage
conversion of harvested
perennial grassland to annual
cropland
Culman et al., 2010. Long-term
impacts of high-input annual
cropping and unfertilized
perennial grass production
AEE, Vol. 137, Issues 1-2, 2010

12. Perennial
grass
Annual
wheat p-value
Harvested
nitrogen (kg ha-1)
47.9 47.2 0.909
Farmers are removing roughly equal amounts of
nitrogen from both systems; annual crop fields
receive over 60 kg ha-1 yr-1 more nitrogen

13. Perennial
grass
Annual
wheat
p-value
Total carbon 182.2 138.8 0.027
Total nitrogen 15.4 11.7 0.013
Soil quality (0 – 1.0 m; Mg ha-1):

14. perennial
wheat
Root C of perennial and wheat fields

16. Differences not simply artifacts of obsolete
farming practices such as poor tillage &
fertilizer practices

17. Differences not simply artifacts of obsolete
farming practices such as poor tillage &
fertilizer practices
DuPont et al: No-tillage conversion of native
grassland using best-practices
•reductions in active carbon stocks
•reductions in water stable aggregates
•Negative impacts on soil food webs

18. Conservation Ag: low tillage, rotations, residue maintenance

19. Additional examples
•Sustained harvests of unfertilized perennial
grasslands (USDA county yield data; Shortridge, 1973;
Jenkinson et al., 1994, Silvertown et al., 1994)
•SOC and total soil N not reduced after
decades of unfertilized grassland harvests
(Jenkinson et al., 2004; Mikhailova et al., 2000, Mikhailova and
Post, 2006)

20. (nasa.gov)
1 mm
Photo credit: Jim Richardson

21. (nasa.gov)
1 mm
Photo credit: Jim Richardson
Small-scale processes »» Large-
scale landscape health
minutes and millimeters

23. Humans don’t eat hay

24. Global cropland (% of total area)
Fruits &
vegetables
7%
Roots &
tubers 4%
Tree crops
2%
Forages
11%
Other
3%
Fiber
3%
Cereals, oil
seeds, legumes
68%
From Monfreda et al., 2008

25. Global cropland (% of total area)
Cereals, oil
seeds, legumes
68%
From Monfreda et al., 2008
These are all
annual crops

26. Global cropland (% of total area)
Cereals, oil
seeds, legumes
68%
From Monfreda et al., 2008
Provide for more than
70% of our calories needs

27. Perennial grain crops
Sorghum
Maize
Legumes
Rice
Wheatgrass & wheat
Sunflowers
Oilseeds

28. Washington State University:
Texas A&M:
The Land Institute: perennial
sorghum, sunflower, wheat, +.
Yunnan Academy of Agricultural
Sciences
CSIRO: perennial wheat
Global perennial grain programs
Mich. State Univ.: perennial
wheat & wheatgrass
Swedish University Ag Sci
University of Manitoba
Catedra de Cultivos
Industriales: Lesquerella
(mustard family)
Nepal: perennial wheat
Cornell: perennial maize

29. Domestication:
Intermediate wheatgrass

30. Wild
1 -2
cycles
3
cycles

31. 1 m
Domestication:
Intermediate wheatgrass

32. 1 m
Domestication:
Intermediate wheatgrass

33. X
Wide hybridization:
perennial wheat

34. wheat/wheatgrass//
wheat
wheat/wheatgrass//
wheatgrass
wheatgrass

35. Dr. Dhruba Thapa
Nepal Agricultural Research Council
Khumaltar Laitpur, Nepal
High altitude perennial wheat in western Nepal
“…increase food & forage security
significantly in the region.”

36. “…minimize the
workload of farmers,
especially of women in
the remote areas.”

37. Deeper roots: “…more stable
grain and biomass yields”

38. Deeper roots: “…higher
uptake of selenium, zinc,
iron and other minerals.”

39. “…some of the 25 lines appear
highly resistant to yellow rust.”

40. Perennial Concerns
• Can perennials produce as much
grain?
• Aren’t perennials more vulnerable to
pests and disease?
• Will perennials become weeds?
• How long will it take?

41. Perennial Concerns
 Yield
• Perennials have higher yield potential
• Consider within context of whole system
• Multifunctionality is key

42. Perennial Concerns
 Pests and disease
• Increases potential to diversify rotations,
intercrops, relay systems
• Wide crosses introduce new pathways for
resistance

43. Perennial Concerns
 Weediness
• Unlike perennial forages, perennial grains are
designed to put their energy into seeds not
vegetation

44. Perennial Concerns
 Time
• Farmers already use some perennial grain
legumes—pigeon peas
• Perennial sorghum & rice: field trials within 5
years; farmer-ready within 15 years
• Perennial wheat: farmer-ready in 20 years

45. Perennial Possibilities
 We can transform our farms to
function more like natural ecosystems
 Perennial grain crops are the next step
 Mitigation: If agricultural soils can be
used to offset industrial emissions of
GHGs, perennial crops will be key
 Adaptation: Perennial crops are more
resilient

48. Jerry Glover
USAID
Washington, DC
jglover@usaid.gov