Mr. David A. Lobb, University of Manitoba, Canada. Global Symposium on Soil Erosion (GSER19), 15 - 17 May 2019 at FAO HQ.

1. National Assessment of Soil
Erosion in Canada
from 1971 to 2016
David Lobb1, Sheng Li2, Brian
McConkey2, Nasem Badreldin1,3
1University of Manitoba,2Agriculture and Agri-Food Canada,
3University of Guelph
1

2. Saskatchewan (1980s)
SOIL EROSION IN CANADA
Crop production over the last 100 to 200 years in Canada has
resulted in significant degradation of soil.

3. Saskatchewan (1930s)
The Dirty Thirties
Crop production over the last 100 to 200 years in Canada has
resulted in significant degradation of soil.
SOIL EROSION IN CANADA

4. The Heavy Seventies
SOIL EROSION IN CANADA
Crop production over the last 100 to 200 years in Canada has
resulted in significant degradation of soil.

5. Assessment and Prediction Models:
Agriculture and Agri-Food Canada’s
Agri-Environmental Indicators program
Soil Erosion Risk Indicator models
ASSESSMENT OF SOIL EROSION
2000 20102005 2016

6. 849
89
162 Ecoregions
Ecodistricts
Ecozones
SLC Polygons
(#89 = 0.13 million ha)
Canada
(#849 = 0.9 million ha)
(#162 = 3.3 million ha)
(Prairie = 6.5 million ha)
Figure1: Map of the province of Manitoba illustrating the spatial framework of biophysical data
in Canada. Source: Agriculture and Agri-food Canada.
Agriculture and Agri-Food Canada
Agriculture et Agroalimentaire Canada
Manitoba
0 250 500 1000
ProjectionAzimutaldeEqui-airedeLambert
0 500250 750 1000 1500
LambertAzimuthalEqualAreaProjection
ECHELLE ESCALA SCALE
1:45000000
miles
Kms.
ProyeccionAzimultaldeEqui-areadeLambert
15
1
1
1
1
2
2
2
2
2
2
2
7
7
3
6
3
3
5
55
5
5
5
5
8
9
9
6
10
6
7
7
11
10
10
6
13
12
13
12
14
13
14
15
14
14
4
COMMISSION DE
CO
COMISIONPARALA
COOPERACIONAMBIENTAL
COMMISSIONFOR
ENVIRONMENTALCOOPERATION
CCE
CCA
CEC
OP RATIONENVIRONNEMENTAL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
NIVEAU I. NIVELI. LEVELI
CORDILLEREARCTIQUE
CORDILLERAARTICA
ARCTICCORDILLERA
TOUNDRA
TUNDRA
TUNDRA
TAIGA
TAIGA
TAIGA
PLAINED'HUDSON
PLANICIEDEHUDSON
HUDSONPLAIN
FORETSSEPTENTRIONALES
BOSQUESSEPTENTRIONALES
NORTHERNFORESTS
MONTAGNESFORESTEESDUNORD-QUEST
MONTANASBOSCOSASNOROCCIDENTALES
NORTHWESTERNFORESTEDMOUNTAINS
FORETMARITIMEDELACOTEOCCIDENTALE
BOSQUECOSTEROOCCIDENTAL
MARINEWESTCOASTFOREST
FORETSTEMPEREESDEL'EST
BOSQUESTEMPLADOSDELESTE
EASTERNTEMPERATEFORESTS
GRANDESPLAINES
GRANDESPLANICIES
GREATPLAINS
DESERTSDEL'AMERIQUEDUNORD
DESIERTOSDENORTEAMERICA
NORTHAMERICANDESERTS
CALIFORNIEMEDITERRANEENNE
CALIFORNIAMEDITERRANEA
MEDITERRANEANCALIFORNIA
HAUTESTERRESSEMI-ARIDESMERIDIONALES
ELEVACIONESSEMIARIDASMERIDIONALES
SOUTHERNSEMI-ARIDHIGHLANDS
SIERRASTEMPEREES
SIERRASTEMPLADAS
TEMPERATESIERRAS
FORETSTROPICALESSECHES
SELVASCALIDO-SECAS
TROPICALDRYFORESTS
FORETSTROPICALESHUMIDES
SELVASCALIDO-HUMEDAS
TROPICALWETFORESTS
Limiteinternationale
Limiteinternacional
Internationalboundary
LimitederegionsNiveauI
LimitederegionesNivelI
RegionboundaryLevelI
Figure 2: Ecozones of North America. Source: Commission for Environmental Cooperation.

7. Soil Landscape Canada (SLC) Polygon,
10,000 – 1,000,000 ha
TillERI
Erosion Models
Landform
National Soil
Database
(NSDB)
Census of
Agriculture
1981- 2016
Soil,
Topography
Climate
Stations
Long Term
Climate Data
Crop type,
Tillage
Up
Mid
Low
Dep
WaterERI WindERI
SoilERI
Province
Canada
Data inputs
Aggregation
Aggregation
Aggregation
ShengLietal.,WCSS,2010

8. • 19 landform types:
• 7 surface forms
• 1 – 4 slope classes
• 4 segments (some only have 3):
• Up, Mid, Low and Depression
• length and slope gradient
• Calculation unit:
• Landform (hill slope)
• Multiple hill slopes in one SLC polygon
• Allocation:
• Soil, crop type, tillage system
• Each segment in each landform
Landform
Up
Mid
Low
Dep
ShengLietal.,WCSS,2010

9. • Equation (WindERI)
• Wind Erosion Equation (WEQ)
• AWd = f(I,K,C,L,V)
• Individual factors
• C-, L- and V-factor for the hillslope
• I- and K-factor for each segment
• Adjustments
• Expert knowledge
○ Processes and conditions in Canada
Landform
Up
Mid
Low
Dep
TillERI
Erosion Models
WaterERI WindERI
SoilERI
ShengLietal.,WCSS,2010

10. • Equation (WaterERI)
• Universal Soil Loss Equation (USLE)
• ATi = R • K • LS • C • P
• Individual factors -- RUSLE
• R-, C- and P-factor for the hillslope
• K- and LS-factor for each segment
• Adjustments -- RUSLE2
• Interactions between factors
• Soil accumulation rates
• Regression equations
• Intensive test runs in RUSLE2
Landform
Up
Mid
Low
Dep
TillERI
Erosion Models
WaterERI WindERI
SoilERI
ShengLietal.,WCSS,2010

11. • Equation (TillERI)
• ATi = ET • EL
• Erosivity of tillage (ET)
• Crop type and tillage system
○ Tillage equipment
○ Number of passes per year
• Field experiment data
• Erodibility of Landform (EL)
• Slope gradient and slope length
Landform
Up
Mid
Low
Dep
TillERI
Erosion Models
WaterERI WindERI
SoilERI
ShengLietal.,WCSS,2010

12. soil loss
soil
accumulation
soil
accumulation
Tillage erosion is the net redistribution (losses and gains) of soil resulting from the
variability in the movement of soil by tillage.
Cropping and tillage systems that employ intensive tillage (frequent, deep, fast)
can cause severe tillage erosion.
ET

13. • SoilERI model (SoilERI)
• ASoil = ATi + AWt + AWd
• For each segment in each landform (hillslope)
• Aggregation
• Area-weighted across
○ Landform
○ Crop type
○ Tillage system
• Value for each segment
○ SLC polygon
○ Province
○ Canada
Landform
Up
Mid
Low
Dep
Soil Landscape Canada (SLC) Polygon,
10,000 – 1,000,000 ha
TillERI
Erosion Models
WaterERI WindERI
SoilERI
Province
Canada
Aggregation
Aggregation
Aggregation
ShengLietal.,WCSS,2010

14. Assessment and Prediction Models:
Classes of Soil Erosion / Degree of Soil Loss:
Extremely Low / Negligible0 – 3 t ha-1 yr-1
3 – 6 t ha-1 yr-1
6 – 11 t ha-1 yr-1
11 – 22 t ha-1 yr-1
22 – 33 t ha-1 yr-1
>33 t ha-1 yr-1
}Sustainable
ASSESSMENT OF SOIL EROSION

15. * Upper slopes
ASSESSMENT OF SOIL EROSION
Distribution of Soil Loss Rates for 1971 and 2011: Wind Erosion
Soil Erosion Risk Classes
1971
2011

16. * Upper + Mid slopes
ASSESSMENT OF SOIL EROSION
Distribution of Soil Loss Rates for 1971 and 2011: Water Erosion
Soil Erosion Risk Classes
1971
2011

17. * Upper slopes
ASSESSMENT OF SOIL EROSION
Distribution of Soil Loss Rates for 1971 and 2011: Tillage Erosion
Soil Erosion Risk Classes
1971
2011

18. Distribution of Soil Loss Rates for 1971 and 2011: Soil Erosion
Soil Erosion Risk Classes
1971
2011
ASSESSMENT OF SOIL EROSION

19. CONCLUSIONS
• The annual rates of soil erosion by wind, water and tillage, and
their combination, have declined over the past 45 years in
response to the decline in use of intensive tillage practices.
However, a considerable amount of cropland remains at
moderate to very high rates of soil erosion.

20. Provincial Overview of Soil Erosion Between 1971 and 2011:
Wind, Water and Tillage Erosion, combined as Soil Erosion
Negligible Very Low Low Moderate High Very High
1971 2011 1971 2011 1971 2011 1971 2011 1971 2011 1971 2011
BC 17.1 54.6 22.9 32.4 48.3 9.0 8.6 1.9 0.4 0.5 2.6 1.6
AB 20.9 65.8 32.5 20.3 13.3 10.3 20.2 3.2 7.0 0.3 6.0 0.0
SK 0.0 60.1 19.5 22.7 44.2 15.9 17.2 1.2 15.3 0.0 3.7 0.0
MB 4.2 15.5 37.6 55.7 23.2 19.2 29.5 9.3 5.0 0.3 0.6 0.0
ON 5.5 10.0 16.4 17.8 10.4 14.5 25.0 29.0 18.6 15.4 24.0 13.4
QC 56.8 53.1 16.9 22.5 11.4 11.5 10.6 9.7 2.8 1.6 1.6 1.5
NB 20.6 27.4 21.1 16.0 32.9 33.7 7.9 9.6 7.0 6.5 10.4 6.9
NS 7.2 9.9 15.3 38.9 36.5 33.6 38.3 15.6 1.6 1.6 1.2 0.4
PE 11.5 11.9 7.5 7.9 4.1 3.9 65.7 76.3 11.2 0.0 0.0 0.0
NF 2.7 16.6 11.6 14.5 13.8 6.2 5.9 39.9 25.7 22.8 40.4 0.0
Can 9.4 50.5 24.9 25.6 28.9 14.4 20.0 6.3 11.3 1.7 5.5 1.4
ASSESSMENT OF SOIL EROSION

21. Negligible Very Low Low Moderate High Very High M to VH
1971 2011 1971 2011 1971 2011 1971 2011 1971 2011 1971 2011 1971 2011
BC 17.1 54.6 22.9 32.4 48.3 9.0 8.6 1.9 0.4 0.5 2.6 1.6 11.7 4.0
AB 20.9 65.8 32.5 20.3 13.3 10.3 20.2 3.2 7.0 0.3 6.0 0.0 33.3 3.6
SK 0.0 60.1 19.5 22.7 44.2 15.9 17.2 1.2 15.3 0.0 3.7 0.0 36.2 1.2
MB 4.2 15.5 37.6 55.7 23.2 19.2 29.5 9.3 5.0 0.3 0.6 0.0 35.1 9.6
ON 5.5 10.0 16.4 17.8 10.4 14.5 25.0 29.0 18.6 15.4 24.0 13.4 67.7 57.8
QC 56.8 53.1 16.9 22.5 11.4 11.5 10.6 9.7 2.8 1.6 1.6 1.5 14.9 12.9
NB 20.6 27.4 21.1 16.0 32.9 33.7 7.9 9.6 7.0 6.5 10.4 6.9 25.3 22.9
NS 7.2 9.9 15.3 38.9 36.5 33.6 38.3 15.6 1.6 1.6 1.2 0.4 41.1 17.6
PE 11.5 11.9 7.5 7.9 4.1 3.9 65.7 76.3 11.2 0.0 0.0 0.0 76.9 76.3
NF 2.7 16.6 11.6 14.5 13.8 6.2 5.9 39.9 25.7 22.8 40.4 0.0 71.9 62.7
Can 9.4 50.5 24.9 25.6 28.9 14.4 20.0 6.3 11.3 1.7 5.5 1.4 36.8 9.5
ASSESSMENT OF SOIL EROSION
Provincial Overview of Soil Erosion Between 1971 and 2011:
Wind, Water and Tillage Erosion, combined as Soil Erosion

22. CONCLUSIONS
• Tillage erosion is a major cause for moderate to high rates of soil
erosion, and should be the focus of future soil conservation
efforts.
Conservation tillage must focus on the amount of soil movement
during tillage as well as the amount of crop residue left on the
soil surface.

23. CONCLUSIONS
• An integrated approach to managing all forms of soil erosion is
necessary to minimize soil loss and restore eroded soils.
This can be challenging. Some soil conservation practices will
reduce one form of erosion while exacerbating another form. In
particular, tillage practices that are effective in reducing wind and
water erosion are not necessarily effective against tillage erosion.
For example: the chisel plough leaves more crop residues on the
soil surface than the moldboard plough, providing more
protection against wind and water. At the same time, the chisel
plough can move soil over a much greater distance and cause
more tillage erosion.

24. There are tillage operations that are
more erosive than the mouldboard
plough
We must consider how far soil is moved
during tillage as well as how much crop
residue is left on the soil surface
• We must redefine and redesign conservation tillage, and foster
its implementation.

25. • We must redefine and redesign conservation tillage, and foster
its implementation.
The current trend is towards higher speed
tillage, throwing soil much further
There are tillage operations that are
more erosive than the mouldboard
plough

26. Even seeding operations
move a lot of soil and cause tillage erosion
• We must redefine and redesign conservation tillage, and foster
its implementation.
There are tillage operations that are
more erosive than the mouldboard
plough

27. Even crop management operations
move a lot of soil and cause tillage erosion
• We must redefine and redesign conservation tillage, and foster
its implementation.
There are tillage operations that are
more erosive than the mouldboard
plough

28. CONCLUSIONS
• The assessment of soil erosion must consider both the annual
rates and cumulative total of soil loss. It is necessary to know the
historical impact of soil erosion to target effective management
practices to sustain or enhance soil and crop productivity and
profitability.

29. Soil Loss and Yield Loss Relationship:
0
10
20
30
40
50
60
70
80
90
100
0102030405060708090100
Amount of original topsoil remaining (%SOC)
Cropyield(%)
2xDTS
1xDTS
* non-linear response
ASSESSMENT OF SOIL EROSION

30. 1971 2011
Units
Low-
Eroding
Cropland
(N-L)
High-
Eroding
Cropland
(M-VH)
Total Low-
Eroding
Cropland
(N-L)
High-
Eroding
Cropland
(M-VH)
Total
Cropland Area ha 25,149,351 14,663,025 39,812,376 35,211,104 3,676,329 38,887,434
% 63.2 36.8 100 90.5 9.5 100
Soil Loss Rate t ha-1 yr-1 5.9 24.0 3.5 22.7
Relative Crop Yield % 99.5 83 95 40
Crop Yield Loss % 0.5 17 5 60
Annual Soil Loss and Crop Yield Loss in 1971 and 2011
* no net improvement *
ASSESSMENT OF SOIL EROSION

31. • Conservation tillage simply reduces the loss of soil organic
carbon and productivity, we must focus on good crop
management to increase organic carbon inputs into the soil
and increase soil and crop productivity.

32. Assessment of the Cost of Soil
Erosion to Crop Production
in Canada
Nasem Badreldin1,2, David Lobb1
1University of Manitoba, 2University of Guelph
32

34. A
B
C
Soil-landscape variability in a hilly landscape
unbroken, uncultivated
negligible soil erosion
variability caused by pedogenic processes
THE COST OF DOING NOTHING

35. A
B
C
Soil-landscape variability in a hilly landscape
few decades of cultivation (~1940)
juvenile state of erosion
THE COST OF DOING NOTHING

36. • There is growing urgency to take effective action.
• Increasing variability in climate and the increasing severity
and frequency of weather extremes can only amplify the
losses in crop production and threaten farm and food
security.
THE COST OF DOING NOTHING

37. • There is growing urgency to take effective action.
• Increasing variability in climate and the increasing severity
and frequency of weather extremes can only amplify the
losses in crop production and threaten farm and food
security.
• The degradation of soil landscapes is increasing in areal
extent, more of farm fields are suffering the loss of topsoil.
This is a result of progressive tillage erosion.
THE COST OF DOING NOTHING

38. A
B
C
Soil-landscape variability in a hilly landscape
several decades of cultivation (~1990)
mature state of erosion
THE COST OF DOING NOTHING

39. A
B
C
Soil-landscape variability in a hilly landscape
continued cultivation (~2010)
advanced state of erosion
entire soil-landscape degraded
There is a need for effective and
preventative and corrective action!
THE COST OF DOING NOTHING