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Trends in Summer Fallow and Climate Variables in the Canadian Prairies. S. Gameda, B. Qian, C. A. Campbell, R. Desjardins WMO Expert Meeting Contribution of Agriculture to the State of Climate September 27-30, 2004. Land Use Change in the Canadian Prairies.
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Trends in Summer Fallow and Climate Variables in the Canadian Prairies S. Gameda, B. Qian, C. A. Campbell, R. Desjardins WMO Expert Meeting Contribution 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?
Some trends in summer and winter temperature and precipitation for the different soil zones
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?