Top Crop Manager

Features Agronomy Cereals
Wheat quality setback courtesy of ‘Mother Nature’

Excess moisture contributes to field variations in protein content.

November 20, 2007
By Top Crop Manager


According to Thom Weir, the 2005 growing season presented producers with serious
excess moisture problems in the region along the Manitoba-Saskatchewan border.
Weir is the manager of agronomic services with Saskatchewan Wheat Pool located
at Yorkton. Rainfall in June ranged between eight to 12 inches, which left the
soils in many fields totally saturated. As a result, crops in the low-lying
portions of these fields turned a yellowish colour. However, once the fields
dried out, the crops appeared to recover.

Weir, a seasoned CCA agronomist, was well aware of the potential negative impact
of these conditions on wheat quality. He followed the performance of some of
these crops throughout the summer. He indicated that growth conditions were
excellent following the wet June period and that the yellow plants largely disappeared.
However, Weir stated that "While the formerly yellow, N deficient wheat
plants seemed to grow out of the problem and appeared almost normal, the growth
was not quite as robust as might usually be expected in the lower areas of a

Excessive amounts of June rainfall left many young wheat crops in
saturated soils. Thom Weir suspects that in these areas a considerable amount
of N was lost from the soil due to denitrification.

The fact that the growth of wheat in the lower areas was equal to that of the
upland areas helped to somewhat ease Weir's concerns; he also knew there was
potential for a negative impact of the excess moisture on losses of N. Since
many growers had applied 80 to 90 pounds per acre of N fertilizer, Weir was
hopeful that this relatively high rate of N would still help to produce a good
crop of wheat that would grade #1.


Although there was speculative 'coffee shop talk' among growers about the impact
of surplus moisture on wheat quality, they did not raise this concern with Weir
during the growing season. However, this changed dramatically once the growers
started to bring in the first combined wheat samples. Growers begin to call
Weir about the fact that their wheat samples were grading #2 due to the low
levels of Hard Vitreous Kernels (HVK) in their samples.

To achieve #1 status, a wheat sample must contain a minimum of 65 percent of
HVK kernels. Weir noted that the samples had a relatively high percentage of
kernels that were piebald or starchy in appearance. Piebald kernels are an indication
of low wheat protein content. He quickly realized that his concern about the
yellow patches of young wheat plants had come to fruition. Unfortunately, the
relatively high levels of N fertility had not been enough to counteract the
impact of excessive June rainfall.

The protein content of the wheat samples was below 12 percent. Weir decided
to split the kernels into those that appeared to meet the HVK requirement and
those that were starchy in appearance. When he submitted the split sample for
analysis, the good-looking sample tested 14 percent and the piebald sample tested
only 10 percent in protein content.

According to Weir, "The wheat with a higher HVK rating probably came from
the upland or better-drained portions of the field, while the majority of the
piebald kernels came from the lower-lying areas of the field that were saturated
with water. The cause of the yellowed wheat plants as well as the piebald kernels
was the loss of soil N due to excess moisture. Under waterlogged conditions,
N can be lost from the soil through a process called denitrification. This process
results in the conversion of nitrate N into one of several gaseous forms of
N that are lost to the atmosphere."

Emil Strutynski, who operates Strut Farms with his son Mark, appreciates Weir's
insight into this quality issue and indicated that they had relied on his agronomic
expertise for many years. Emil compliments Weir for 'his hard work and the fact
that he likes to work with farmers to solve problems'. Mark states, "Thom
is an excellent agronomist who always gets answers to our agronomic crop production
questions. It sure helps to have him around. He is a big asset to our farming
operation." -30-

Thom Weir
was one of the first prairie agronomists to become certified under the International
Certified Crop Advisor (CCA) program. His agronomic expertise is widely recognized
within the crop production industry. His fellow CCAs honoured him for his contributions
by selecting him as the winner of the '2002 Certified Crop Advisor of the Year'
for the prairie CCA Region.

* * *

Top Crop Manager regularly carries
a story featuring certified crop advisors from various regions of western Canada.
There are more than 700 individuals who have achieved the certification and
maintain this designation through continuing education.