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Soybeans in Saskatchewan?

A question of maturity under prevalent conditions.


November 15, 2007
By Bruce Barker

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The explosion of soybean acres in Manitoba raises the question of whether soybeans
can be successfully grown in Saskatchewan. With the maturity characteristics
of current varieties, the short answer is: not any time soon. But there still
may be potential.

Soybeans like warm and wet weather, as compared to chickpeas and lentils that
prefer warm and drier weather, and peas that like cooler weather. Ray McVicar,
provincial special crops specialist with Saskatchewan Agriculture and Rural
Revitalization at Regina, says that while parts of Saskatchewan may have enough
Corn Heat Units (CHU) to grow soybeans to maturity, the difficulty is how the
CHUs accumulate.

"If you have a hot and wet growing season, you'll see a good crop,"
explains McVicar. "The problem is that we can't always build up those heat
units, especially at night. Soybeans seem to shut down growth when nighttime
temperatures fall below 13 to 14 degrees C. You need warm nights to grow soybeans."

While soybeans have performed well in Manitoba, although the cold 2004 put
the damper on expectations, moving further west increases the risk. Moving out
of the Red River valley towards Alberta means a gradual rise in elevation, and
increasingly cool nights. Moving further north also results in cooler nights.

A quick look at a map of Saskatchewan CHUs shows a few areas with potential
for soybean production, including under irrigation at Outlook. Registered soybean
varieties start with maturity ratings of 2400CHU and go up from there, with
maturity taking up to 120 days. Clearly, those varieties would be borderline
in most areas of Saskatchewan. Plus under irrigation, the difficulty is that
the crop has to be more profitable than other high value crops, such as dry
beans or timothy hay for export.

In Saskatchewan, the Crop Development Centre (CDC) started screening soybeans
for the Western Canadian Co-op Trials in 2003. In 2004, they had 40 genotypes,
which were assessed for maturity, along with other plant characteristics.

"The big limitation is early maturity," says Bert Vandenberg, a professor
and researcher with CDC at the University of Saskatchewan. "However, the
plant has been shown to be very plastic around the world so we felt that we
should start looking at soybean germplasm sooner rather than later."

Vandenberg says CDC is not conducting plant breeding work since there is no
funding support. Indeed, even the soybean screening is done without support
because the CDC believes in assessing new crops.

Vandenberg notes that at one point in time, soybeans were grown only in the
southern US. Of course, plant breeding has moved the area of adaptation much
further north. He thinks the area with the greatest potential is southeast Saskatchewan,
because of the higher humidity and rainfall. Soybeans do not like dry weather,
so the combination of heat and moisture is critical.

Terramax, a Regina company, has also conducted research into soybean production
using early maturing varieties from the US. Terramax has seen yields between
25 to 35 bushels per acre on dryland areas of southern Saskatchewan and more
than 50 bushels per acre under irrigation.

McVicar says that some of the soybean plots that he has observed vary greatly,
depending on soil type. He says that the heavy clay soils around Regina have
not produced good yields, likely because the heavy soil remains cooler. Moving
eastward towards Indian Head, on lighter soils, yields have been better.

Still the current potential is full of risk. "Because we are on the edge
of the area of adaptation, the risk is high," says McVicar. "You have
to look at whether soybeans will make you more money than a different, well-adapted
special crop."

In Vandenberg's plots, a few soybean varieties were maturing at the end of
September 2004. Others were still green, and the potential of a harvested crop
for those was very low. Whether varieties will ever be developed for Saskatchewan
maturity and conditions will not be answered soon. Still, there is a glimmer
of potential.

"It is worth investigating. From a pulse perspective, soybeans occupy
a good niche in the ecosystem. We think they should be looked at," says
Vandenberg. -30-