70th SWCS International Annual Conference July 26-29, 2015 Greensboro, NC

1. The Forgotten
Piece of the
Water-Energy-
Food Nexus
SOIL

2.  Personal journey
 Current state of soils
 Nexus of Water-Food-Energy
OUTLINE

3. PERSONAL JOURNEY

4. “Scientists are really very conscious of the fact that they stand
on the shoulders of an enormous tree of preceding workers
and that their own contribution is not so enormous”
MARTIN FLEISCHMANN

5. CURRENT STATE OF SOILS

6. SOIL DEGRADATION
Soil degradation is defined as a change in
the soil health status resulting in a
diminished capacity of the ecosystem to
provide goods and services for
its beneficiaries. Degraded soils have a
health status such, that they do not provide
the normal goods and services of the
particular soil in its ecosystem. FAO, 2015
“The nation that destroys its soil, destroys itself.” -
Franklin Delano Roosevelt

7. SOIL DEGRADATION SPIRAL
Poor Land Management
Aggregation Degradation
Compaction
& crusting
Water & Wind Erosion
Plant Growth Soil Biology
Yield
Reduced Soil
Productivity

8. THE TRUTH
1870 1890 1910 1930 1950 1970 1990
Year
0
1
2
3
4
SoilOrganicCarbon(%)
Wheat, 6 Tons Manure/year
Corn, 6 Tons Manure/year
Continuous Wheat
Continuous Corn
Sanborn Field: Missouri
Estimated
to 4 % in 1888
Wagner (1989)
Morrow Plots: Illinois
Corn-Oats-Hay Rotation
Corn-Oats (1885-1953, Corn-Soybeans (1954-Present)
Continuous Corn
Long Term Effects of Crop Rotations
Corn systems are slightly carbon positive with
all residue returned and negative in a corn-
soybean system and even more so with tillage
and residue removal

9. COMMON SCENES

10. EROSION: HOW MUCH IS TOLERABLE
Loss of farm income due to erosion is estimated at $100 million per year
in the US, Crosson (2007)

11. Credit: Roger Wolfe, Baltimore, OH
after 1 year
0.025 inch soil loss
~4 tons/yr
after 40 years
1.0 inch soil loss
~160 tons
Erosion from 1 acre of land (43,560 ft2)!

12. CROP INSURANCE CLAIMS
Midwest Corn Production
Year
1985 1990 1995 2000 2005 2010 2015
TotalClaims
0
1000
2000
3000
4000
5000
Excessive Moisture/Precipitation
Drought
Frost
Excessive moisture and drought account for 55% of the claims and since
1989 have exceeded $12 billion in payments
Midwest Soybean
Year
1985 1990 1995 2000 2005 2010 2015
TotalClaims
0
1000
2000
3000
4000
5000
Excessive Moisture/Precipitation
Drought
Frost

13. SOIL DEGRADATION SPIRAL
Poor Land Management
Aggregation Degradation
Compaction
& crusting
Water & Wind Erosion
Plant Growth Soil Biology
Yield
Reduced Soil
Productivity

14.  Excessive Tillage
 Residue Removal
POOR LAND MANAGEMENT
Hatfield, 2014, Soil Degradation, Land Use, and Sustainability In Songstad,
Hatfield, and Tomes, Convergence of Food Security, Energy Security and
Sustainable Agriculture

15. GOOD SOILS = GOOD YIELDS
Mean NCCPI
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
CountyYield(gm-2
)
180
200
220
240
260
280
300
320
340
Kentucky
Iowa
Nebraska
Kentucky
(Double crop)Y = 131.187 + 187.458X. r2
= 0.72***
County average soybean
yields (1950-2012) across
Iowa, Kentucky, and
Nebraska,
Egli and Hatfield, 2014, Agron J. 106:560-566; 106:2248-2254
NCCPI-AG
0.4 0.6 0.8 1.0
MeanCountyYield(gm-2
)
500
600
700
800
900
1000
Kentucky
Iowa
County average corn yields
(1950-2012) across Iowa and
Kentucky

16. NCCPI
ACROSS THE
MIDWEST

17. VULNERABLE AREAS OF THE WORLD

18. SOIL AGGRADATION CLIMB
Biological Activity
Improved Nutrient Cycling
Organic Matter Turnover
Improved Soil Structure
Improved Water
Availability
Efficiency
Yield
Profit
We build soil through biological activity not by physical or chemical manipulation

19. Creating a stable
environment and feeding
the complex soil biology
working hard for you
below the surface.
Crop residue benefits
Simple crop residue on
the surface

20. CREATE A STABLE HOME FOR THE SOIL
BIOLOGY
Which table would you rather eat at?
What if your home was constantly exposed to environmental damage?

21. Source: Sa, 2004
Evolution of a continuous no till systems: 4 phases
Initial Transition Consolidation Maintenance
Time (years)
o Rebuild
aggregates
o Low 0M
o Low crop
residues
o Reestablish
microbial
biomass
o > N
 Increase soil
density
 Start increasing
crop residue
 Start increasing
soil OM
 Start increasing
P
 Immobilize N >=
Minimum
 High Crop
Residue
 High C
 > CEC
 > H2O
 Immobilize N
< Min.
 > Nutrient
Cycling
 High accum. of
crop residue
 Continuous N
and C flux
 Very high C
 > H2O
 High nutrient
cycling
 Less N & P use
0-5 5-10 10-20 >20

22. A SYSTEMS APPROACH
Lal, 2015, JSWC
70:82A-88A

23. WATER-ENERGY-FOOD NEXUS
Food
Energy
Water
Nexus-intersection
of different
components of
which the area of
overlap will vary
Soil is often overlooked when thinking about water, food, or energy resources

24. SOIL RESOURCES
Soils vary in their capacity to provide ecosystem functions

25. VIEWS OF SOIL
Essentially, all life depends upon the
soil ... There can be no life without
soil and no soil without life; they
have evolved together.” - Charles E.
Kellogg, USDA Yearbook of
Agriculture, 1938
“There are two spiritual
dangers in not owning a farm.
One is the danger of
supposing that breakfast
comes from the grocery and
the other that heat comes
from the furnace.” - Aldo
Leopold

26. WATER SECURITY
The function of soil is to store
and provide water for plants
Organic Matter (%)
0 1 2 3 4 5 6 7
AvailableWaterContent(%)
0
5
10
15
20
25
30
35
Data Points
Sand, AWC = 3.8 + 2.2 OM
Silt Loam, AWC = 9.2 + 3.7 OM
Silty clay loam, AWC = 6.3 + 2.8 OM
Hudson, 1994, JSWC

27. FOOD SECURITY
Worldwide Land Availability
Year
1960 1980 2000 2020 2040
LandAreaperCaptia(ha)
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
Productivity per unit area of
land will have to increase to
meet caloric demand from an
increasing population

28.  Nutritional security- restoring depleted agricultural soils,
regenerating topsoil and assuring that the nutritional quality
of harvested food will sustain human health
 It is not the quantity but the quality we produce which will
sustain our population
FOOD OR NUTRITIONAL SECURITY

29. ENERGY SECURITY
Increasing the
efficiency of energy
use in agriculture
Soil management is
a path to increasing
efficiency

30.  Admit we have a growing problem with soil degradation and
we have no new lands to move to, so we need to improve what
we have
 Recognize that improvement will come from practices that
stabilize the soil biological system
 Begin to become more proactive in explaining the role of soil
in the providing the food and water we need to sustain the
population and soil management can reduce the energy needs
for agriculture
CHALLENGES