Submitted to: American Society of Agronomy Monograph Series
Publication Type: Monograph
Publication Acceptance Date: 3/3/2003
Publication Date: 1/2/2006
Citation: Cochran, V.L., Danielson, J.G., Kolberg, R.L., Miller, P. 2006. Dryland cropping in the Canadian prairies and the U.S. Northern Great Plains. In: Peterson, G.A., Unger, P.W., and Payne, W.A. Dryland Agriculture Second Edition, Agronomy Monograph 23. Madison, WI: ASA-CSSA-SSSA. p.293-339.
Interpretive Summary: The northern Great Plains and Canadian Prairies encompasses a large area from Colorado to the eastern border of Kansas and north to the Peace River in Alberta, Canada. Precipitation increases from west to east, across to region, which increases the diversity of crops that can be grown. However, cool temperatures and long winters to the north restricts the number of crops grown. Traditionally, summer fallow alternating with wheat was widely practiced in the region to store precipitation over one season to be used the next when a crop was grown. Intensive tillage was used and this also allowed one to reduce the weed infestation. Changes in government programs, concern over soil erosion, inexpensive herbicides and the development of reduced tillage equipment allowed for less tillage and better storage of soil water. This has increased the intensity and diversity of crops grown in much of the region. In Canada, pulse and oilseed crops have replace summer fallow in much of the region. Acceptance of pulse and oilseed crops in place of fallow has been slower to take hold in the U.S northern Great Plains due in part to the past farm programs. However, the current farm program is more favorable to alternative crops. The availability of large farm machinery has made it possible for one person to farm more acres, which has caused the farms to get larger. This has led to reduced population in many rural communities. The greatest reduction in rural population has been in the driest portions of the northern Great Plains and Canadian Prairies.
Technical Abstract: The northern Great Plains and the Canadian Prairies encompass a vast area from 37º N Lat. to 57 º Lat. and from about 113º W longitude to 95º W longitude. Mean annual precipitation ranges from 300mm in the west to over 900mm in the east. Precipitation occurs primarily during early growing season allowing for both warm and cool season crops. Traditionally, wheat fallow was grown in the area. Clean tillage was used to control vegetation during the fallow year and reduced the need for herbicides. Environmental concerns and inexpensive herbicides have made it possible to reduce the amount of tillage, store more water in the soil, intensify and diversify cropping systems. Changes in the government agricultural programs have also encouraged greater crop diversity. Rotating crops also serves to reduce the weed, disease and insect pests by interrupting the life cycles of insects and disease organisms, then to be crop specific. It also make is possible to rotated herbicides to avoid or delay the onset of resistance to a particular chemical. Pulse and oilseed crop have become a major economic competitors with small grains in Canada and have just recently become a major crop in the northern Great Plains. The topography of the region favors the use of large machinery allowing farm to increase in size, which has resulted on a decrease in rural populations. The greatest out-migration has occurred in the driest areas of the northern Great plains and Canadian Prairies.