Direct seeding helps to diversify crops, which can increase net return.
November 20, 2007 By Top Crop Manager
Increasing crop diversity and using carefully planned crop rotations offer
many well-known benefits such as increased yield, reduced disease, improved
crop residue management and better soil quality. Yet diversifying crop rotations
has been difficult, especially under conventional seeding. But under direct
seeding systems, everything changes.
"Moving to direct seeding often goes hand-in-hand with crop diversity.
As growers reduce tillage, they tend to place more emphasis on crop management
to deal with disease, weed and crop residue, and that generally leads to more
dynamic crop rotations," says Ron Heller, Alberta Reduced Tillage LINKAGES
agronomist at Vermilion. "And with reduced tillage, the grower often can
expand his cropping options because he has better moisture."
|Winter wheat emergence in early May could provide greater crop diversity
in the Parkland area. Photo Courtesy Of Ron Heller, RTL.
In many areas of the Dark Brown and Black soils, direct seeders have expanded
their crop diversity with just the simple addition of pulses into their cropping
plans. A pea-wheat-canola-barley sequence is now common. Heller says that simplistic
approach offers reasonable breaks in disease hosts, and prevents the build-up
of heavy crop residue. However, it does have drawbacks.
For example, the Parkland Conservation Farm (PCF) at Mundare, Alberta, approximately
80km east of Edmonton, has run this rotation for 12 years comparing no-till
versus a tillage system. "Because glyphosate cannot be used in a pre-harvest
application for malt barley, we are finding that Canada thistle can be a problem
in the following pea crop," explains Heller. "We realize that is a
challenge for a short four year rotation."
Recently, the decision was made at PCF to look at the rotation effect of direct
seeding a winter cereal such as winter wheat in place of spring wheat or barley.
A small dynamic change such as fall seeding once in four years could prove beneficial
as a weed control strategy. Heller says there is still a lot to learn about
which crop performs best or fits well within a rotation plan. Whether sequencing
is used for weed control, increasing protein, good fertilizer efficiency, avoiding
disease or insect problems, or just higher yield and better quality, manipulating
these factors begins with the right seeding plan.
"One thing is for sure: diversity is an important part of continuous cropping,
as important as direct seeding to avoid the limitations that have resulted from
continuous tillage," adds Heller.
Flexible rotations target market returns
At Carmangay in southern Alberta, Ron Svanes takes a different approach to crop
diversification in his minimum tillage farming operation. He grows and experiments
with a wide range of crops, so that he can be confident in his crop rotations
while remaining flexible.
"I don't have a definite rotation. I base my decision on market returns,
and moisture and field conditions," explains Svanes. "The rotations
for any given year are usually staggered all over the farm, depending on topography,
soil texture, plant disease and weed pressures. I like to assess each field
and decide which crop will provide me with the best returns."
An example of how Svanes modifies his rotations comes from the last few years
when sawfly pressure built up to unmanageable levels. He says one of his favourite
rotations was to plant hard red spring wheat back-to-back before rotating to
another crop. In his area, disease generally does not build up that quickly
and Svanes was able to generate good crop returns from wheat on wheat. However,
with sawfly continuing to cause problems, he has moved away from wheat on wheat
stubble. "I can usually get away with stacking a cereal for two years in
a row without disease, but sawfly is changing the wheat rotation."
Over the years, Svanes has experimented with many crops, and continues to grow
pedigreed cereal crops, canola, pulses and sunflowers. Along with five other
farmers, he was one of the first in the area to experiment with chickpeas. "Other
than enjoying the challenge of something new on the farm, the primary motivation
for diverse cropping is the economic return," explains Svanes.
Of course, chickpeas have been on a roller coaster ride over the last few years.
The challenges of growing chickpeas have turned a lot of farmers off the crop,
mostly due to the cost of controlling disease, and the losses caused by ascochyta
blight. Along with the disease problem and the high cost of growing a chickpea
crop, chickpeas also dry out the soil at depth, leaving it in poor tilth for
subsequent crops. So why does Svanes continue to grow chickpeas?
"They have been my best paying crop, grossing $375 to $450 per acre. After
eight years of experience, I have a comfort level with weed control, and tolerance
for the lack of weed control, and I am comfortable with the disease management."
Svanes will often plant field peas on chickpea stubble. While plant diseases
are common between the crops, they are of different strains and disease carryover
is not a problem. And because peas are an efficient water user, they can cope
well with shallow moisture penetration in the soil profile and the drier soil
left by chickpeas.
Field peas are the first crop seeded on the Svanes farm, which results in an
early harvest and adequate time for soil-moisture recharge in the fall. Good
yields of 30 to 50 bushels per acre, good harvest and market timing, good soil
tilth, and a protein boost for subsequent cereal crops make field pea a "great
Lentils are another pulse crop that bring challenges and rewards. They have
the same challenges as chickpeas, including poor weed competition, little broadleaf
weed control, indeterminate growth pattern and straight-cut harvest problems.
But Svanes finds that they do have a shallow root system, which makes them a
good rotational crop in drier areas. While other farmers have grown lentils
successfully in southern Alberta, Svanes says he has yet to grow a satisfactory
crop of lentils on his farm in three attempts. "If my wife can put up with
another year of frustration, we will try again."
Svanes has also experimented with early short stature sunflowers, in co-operation
with Alberta Agriculture, Food and Rural Development, and Agriculture and Agri-Food
Canada. His contribution margin varied widely between 2002 and 2003 for the
oil sunflowers. In 2002, he made $225 while he lost $56 in 2003.
In 2003, in co-operation with the Southern Applied Research Association and
Bench Mark Seeds, Svanes also experimented with 23 acres of sorghum-sudangrass
and 15 acres of Siberian millet. Both crops are warm season annual forage crops
and give good yields with limited moisture. While Svanes does not have cattle,
he says the results of the trials show that the crops could be used in a swath-grazing
system or for silage.
Overall, Svanes enjoys the challenge of growing a diverse range of crops. Although
he does admit there are times while combining a mediocre crop of sunflowers
on a cold, windy day in late October he thinks: "Maybe next year I'll just
grow wheat." However, with greater economic potential (although that comes
with economic risk as well), Svanes says increased crop diversity helps him
maintain the flexibility needed to keep ahead of markets, weeds and diseases.
margin of various crops
Ron Svanes of Carmangay, Alberta, provides these numbers for his contribution
margin of various crops on his farm. While he has not figured out the
numbers from 2004, he says the contribution margins in the chart are not
far off. -30-
Cropping alternatives – Continuous
|–||Kabuli chickpea||Spring wheat||Clearfield canola||Field peas||Lentils||Desi chickpea||Oil sunflower||Oil sunflower|
|Source: Ron Svanes, Carmangay, Alberta.|