Dry Pea, Sunflower and Spring Wheat Excel in
Northern Plains Cropping Systems By
Don Comis August
The dry pea is a must in the Northern Plains. Used in
rotations, it has a good effect on many subsequent crop yields and is a
consistent efficient user of precipitation, regardless of how dry or wet the
growing season is.
An Agricultural Research Service (ARS) interdisciplinary team that includes
L. Tanaka and colleagues at the
Great Plains Research Laboratory in Mandan, N.D., found that certain crops
and their residues from no-till farming have a beneficial effect on subsequent
crops, such as corn or spring wheat. In a three-year field experiment on a
research farm near Mandan, the team tested 10 crops each year, for a total of
100 different crop sequence treatment combinations.
Aerial view of crop sequencing
experiment near ARS Northern Great Plains Research Laboratory, Mandan, N. Dak.
Cover photo by Justin Hartel/Marv Hatzenbuhler, July-August 2007
Agronomy Journal, used by
In addition to dry pea, other must" crops for sustainable
no-till cropping systems in the Northern Plains should include sunflower and
spring wheat. Not only do they have a good effect on yields of subsequent
crops, they also consistently use precipitation efficiently. Precipitation use
efficiency, or PUE, is a measurement of pounds of grain or seed harvested per
acre, per inch of precipitation received in a year. Dry pea was a standout in
the study, with the best combination of yield, synergy with succeeding crops
Corn, sorghum and millet generally produced the most crop residue,
offering the best chance of protecting soil and conserving soil water. But too
much residue can interfere with seed planting and reduce yields. Yields were
generally lowest when a crop was planted in its own residue, or if the previous
crop was a late-harvested crop such as corn or sorghum.
This may have been not only because of the heavy residue, but also
because corn and sorghum are thirsty plants that can deplete soil water. The
correct sequence of crops used for successive plantings proved to be important
to sustainable crop production in the Northern Plains.
These and other findings from this experiment are discussed in six
papers in the July-August 2007 issue of the Agronomy Journal.
ARS is the U.S. Department of
Agriculture's chief scientific research agency.