Features Agronomy Corn
RESEARCH REVIEW: February 2007

Western field editor for Top Crop Manager, Bruce Barker has prepared
this synopsis of research projects underway across Canada. While not a comprehensive
list, it provides an update and a prompt to watch the progress of these projects
in demonstration tours during the 2007 season.

Enhancing protein content and yield of spring and
winter wheat through innovative use of legumes in rotation
Among the traditional systems (e.g. grain legumes in rotation with wheat), researchers
clearly demonstrated that including field peas reduces N fertilizer needs in
the following wheat crop by approximately 30kg/ha. Newer grain legume crops
such as dry beans and chickpeas also were found to contribute to the N economy
of a following wheat crop, however the benefits of chickpeas and dry beans were
not as great as from field peas. The magnitude of N fertilizer savings from
these grain legumes was found to be less than 15kg/ha.

Over the four site years of trials, soybeans were found to contribute no rotational
N benefits to a following wheat crop. Therefore, under the conditions of the
present study (current soybean inoculation systems and cultivars), there appears
to be little N benefit from including soybeans in crop rotations. However, soybeans
is still a very good rotation crop and among grain legumes, soybean has a high
tolerance for wet soil conditions.

Information on the rotational benefits of grain legumes presented here will
provide both farmers and the agri-food industry with a better picture of what
can be expected when these crops are included in rotation with wheat.

Dr. Martin Entz, University of Manitoba,
with funding from Manitoba Agri-Food Research and Development Initiative.

Benefits of swine manure injected on wheat
This demonstration was set-up to show hog producers, farmers, agricultural professionals,
and the general public the importance of applying hog manure at rates equal
to the requirements of the crop. High costs of manure application to the land
usually means it is applied at very high rates (usually based on a three year
nitrogen supply). The high rates lead to decreased agronomic performance of
the crop and large N2O contributions to the already dangerous
greenhouse gas levels. Proper application rates will increase crop performance
while significantly decreasing N2O emissions.

The demonstration held in Redvers did not show any negative impact to the crop
yield from the three time rate of swine manure. Release levels of N2O
were not recorded. Swine manure demonstrated the ability to produce yields equal
to and above those of commercial nitrogen applied at 70 pounds per acre.

South East Research Farm Redvers, Saskatchewan,
with funding from AgriArm.

Timing of rolling for chickpeas
Chickpea fields were rolled at three different locations for three years in
southern Alberta. With the exception of the control plot in one year, the study
found no significant differences in yield or disease levels when rolling was
done at planting all the way to the tenth node of the chickpeas. Light rolling
at planting, however, takes advantage of the ideal moisture conditions for burying
the rocks and the lack of weed growth helps to prevent flattening of the crop.
Also, the potential for disease spread becomes a non-issue when rolling before
emergence.

On-farm demonstration conducted by
Alberta Agricultural Research Institute.

Effects of nitrogen-copper interactions on wheat grain
yield and quality
The main purpose of this copper trial is to compare the effectiveness of the
various copper products and their method of application. This trial was located
at Lambert Point, Alberta, under very dry conditions. There were no significant
yield or 1000 kernel weight differences between any of the copper treatments;
moreover, the addition of sulphur did not provide any yield advantage. The lack
of wheat yield response to the addition of copper could be attributed to any
of the following: the site is not copper deficient as expected; because of the
drought, the roots went down deep where soil copper levels were adequate; or
the main yield limiting actor was drought.

North Peace Applied Research Association,
with funding from Alberta Agricultural Research Institute.

The effect of top dressed nitrogen on yield, protein
and quality of durum wheat
Durum markets consistently demand a protein content of 13 percent or higher,
for which there is a premium. During the 1990s, the average protein content
of durum produced on the Canadian prairies has been 12.5 percent or less, leaving
a sizable proportion of the durum crop unsuitable for the premium market.

The overall objective of this project is to determine the effect and relative
efficiency of top dressed N on grain protein, quality, yield and economic return
of durum wheat. Nitrogen at three rates (20kg, 40kg and 60kg/ha) was top dressed
on durum at four growth stages; before germination (during seeding), five leaf,
flag leaf and anthesis. The study was done over three years at two locations:
Indian Head and Swift Current, Saskatchewan. Four cultivars were used.

Increasing the rate of top dressed nitrogen increased the protein content of
the durum. Applying all the nitrogen at seeding provided the most consistent
increases in protein. However, when the yield potential increased during the
growing season due to above normal spring and summer precipitation, protein
levels in the durum seed increased when nitrogen was top dressed during the
growing season.

Indian Head Agricultural Research Foundation,
with funding from AgriArm.

Critical period of weed control in canola
Canola is tolerant of weed competition up to the fourth leaf stage and if weeds
are removed at this time, the canola crop maintains its original yield potential.
In most of the experiments included in this study, the amount of weed re-growth
occurring after the fourth leaf stage of canola was not great enough to cause
canola yield loss. If, however, canola is seeded very early, then weed control
in canola needs to be maintained up to the sixth leaf stage. If non-residual
in-crop herbicides are being used, then an early seeded crop would require two
applications of herbicide, one at the fourth leaf stage to prevent yield loss
due to early season competition and one at the sixth leaf stage to prevent yield
loss from weed re-growth occurring after the initial herbicide application.

In general, the results of this study suggest that for canola seeded in mid
May, one herbicide application at the fourth leaf stage would be sufficient
to prevent yield loss and significantly competitive weed re-growth.

Dr. Rene Van Acker, University of Manitoba,
with funding from Manitoba Agri-Food Research and Development Initiative.
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