agriculture and agriculture et agri-food canada agroalimentaire canada trends in summer fallow and...

Agriculture and Agriculture etAgri-Food Canada Agroalimentaire Canada

Trends in Summer Fallow and Climate Variables in the

Canadian Prairies

S. Gameda, B. Qian, C. A. Campbell, R. Desjardins

WMO Expert MeetingContribution of Agriculture to the State of Climate

September 27-30, 2004


Land Use Change in the Canadian Prairies

• Beginning in the 1870s over 55 Mha of land brought into agricultural production

• Of this, 30-32Mha under annual crops• Summer fallow introduced in the early 1900s for

moisture conservation– Expanded to a peak of 16Mha (late 1960s)– Currently ~ 5.5-6.0Mha

• What impact has this had on regional climate?• Is it possible to differentiate the agricultural “signal”

from climate variability and change?


Soil Zones

Bro wn C he rn o ze mDk. Bro wn C he rno ze mBla c k C he rno ze mDk. G ra y Luviso lG ra y Luviso l

N o n Ag ric .

M anitoba

Saskatchewan

Alberta

Pre p a re d b y theSa ska to o n La nd Re so urc e Unit

M a rc h 1996


Some Characteristics of the Canadian Prairies

Soil Zone Mean Annual Temp. (C)

Annual Precip.

(mm)

ET

(mm)

Deficit

(mm)

Brown 5 <350 700 400

Dark Brown 2-5 350-425 650 250-275

Black 0-2 >400 500-600 0-150


Area Under Summer Fallow

Soil

Zone

Crop Land

(M ha)


(Millions of hectares)

1975 1980 1985 1990 1995 2000

Brown 6.5 3.1 3.1 2.9 2.8 2.9 2.5

Dark

Brown

8.5 3.6 3.4 2.7 2.6 2.1 1.6

Black 15.0 4.7 4.2 2.6 2.6 2.0 1.3

Total 30.0 11.4 10.7 8.2 8.0 7.0 5.4



0.0

1.0

2.0

3.0

4.0

5.0

1975 1980 1985 1990 1995 2000

Year

Are

a (M

ha) Brown

Dark Brown

Black


Some trends in summer and winter temperature and

precipitation for the different soil zones


Ecodistrict, 825 (Brown) JJA Tmax

20212223242526272829

1950 1960 1970 1980 1990 2000Year

Tem

p (

C)


Ecodistrict, 825 (Brown) JJA Tmin

8

9

10

11

12

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 825 (Brown) DJF Tmax

-15

-10

-5

0

5

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 825 (Brown) DJF Tmin

-25

-20

-15

-10

-5

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 825 (Brown) JJA and DJF P

0

50

100

150

200

250

300

350

1950 1960 1970 1980 1990 2000Year

P (

mm

)


Ecodistrict, 776 (Dark Brown) JJA Tmax

20

22

24

26

28

30

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 776 (Dark Brown) JJA Tmin

8

9

10

11

12

13

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 776 (Dark Brown) DJF Tmax

-20

-15

-10

-5

0

1950 1960 1970 1980 1990 2000

Year

Tem

p (

C)


Ecodistrict, 776 (Dark Brown) DJF Tmin

-26-24-22-20-18-16-14-12

1950 1960 1970 1980 1990 2000

Year

Tem

p (C

)


Ecodistrict, 776 (Dark Brown) JJA and DJF P

0

50

100

150

200

250

300

350

1950 1960 1970 1980 1990 2000Year

P (

mm

)


Ecodistrict, 736 (Black) JJA Tmax

202122232425262728

1950 1960 1970 1980 1990 2000

Year

Tem

p (C

)


Ecodistrict, 736 (Black) JJA Tmin

6789

101112

1950 1960 1970 1980 1990 2000

Year

Tem

p (C

)


Ecodistrict, 736 (Black) DJF Tmax

-18-16-14-12-10-8-6-4-20

1950 1960 1970 1980 1990 2000

Year

Tem

p (C

)


Ecodistrict, 736 (Black) DJF Tmin

-30

-25

-20

-15

-10

1950 1960 1970 1980 1990 2000Year

Tem

p (

C)


Ecodistrict, 736 (Black)JJA (Red) and DJF (Blue) P

050

100150200250300350

1950 1960 1970 1980 1990 2000

Year

P (

mm

)


Summary of Trends In Climatic Variables

Summer (JJA) Winter (DJF)

Brown No trends in Tmax,

Slight increase in Tmin

Increase in Tmax, Tmin

Marginal increase in Precip. No trends in Precip.

Dark Brown

No trends in Tmax, Tmin. Increase in Tmax, Tmin

No trends in Precip. Marginal decrease in Precip.

Black No trends in Tmax, Tmin Increase in Tmax, Tmin

Increase in Precip. Decrease in Precip.


Land Use Trend Considerations

• Significant shifts in use of fallow on the Canadian Prairies– Increase from advent of agriculture to ~1965-70

• (max ~ 16M ha)

– Decrease to 5.5 -6.0 M ha

• Similar large scale shifts in Northern US• Impacts of type of fallow

– Tillage (bare soil)– Chemical (light cover)

• Implications wrt regional climate– Summer/winter temperatures, precipitation


Land Use – Climate Interactions

• What impact does the use of summer fallow on such a large scale have on regional climate?

• How can this be differentiated from climate variability and climate change?

agriculture and agriculture et agri-food canada agroalimentaire canada trends in summer fallow and...

Documents

tmin increase

annual crops summer

mha of land

tmin marginal increase

climate variables

canadian prairies soil

c annual precip

slight increase