I don’t farm, I am just an all-knowing farm writer.
But, one of the most common messages I hear from the experts is for producers
to keep the seeding rate up.
There are several benefits to this, which first
includes simply having enough plants in the field to optimize your yield, but
it is also important for choking out weeds and other benefits.
And in talking with a few producers for March 22
farmer panel of Grainews (which will be out this week) this is also an
important consideration for them,
as well. Their experience shows that not all grains (or varieties) are
created equal and as good as seeding technology is today, it is worth checking
to make sure the equipment is delivering what is supposed to do?
I know producers are always looking for fun things to
do, to fill that spare time after seeding, but I think it would be interesting
once the crop emerges to go back and actually do a few square foot counts to
see if you really do have the number of plants growing according to
The recommendations vary, so it is best to check with
provincial departments of agriculture or a local crop consultant for their
advice on the matter. On the Alberta Agriculture website for example, plant
populations for most grains – wheats, oats and barleys – should average 20 to
square foot, with peas about seven plants per square foot, lentils about 12
plants, and there are figures for other crops as well.
Since varieties and seed batches can vary, one
often-recommended exercise for determining the proper seeding rate is to use
the 1000 kernel weight formula. Crop advisor Steve Larocque, of Beyond Agronomy
in Three Hills, Alberta, recommends this five step process for calculating
cereal seeding rate:
- Take a
germination and vigor test. I like to have a disease test done as well to
determine what seed treatments we should be focusing on to control any
seed born infections, or find another seed supply.
out 1,000 kernels. Before you say yah right Steve, you can count out 100
seeds and multiply it by 10 to get your thousand kernels. You may call it
cheating, but I call it efficiency and know that the either method yields
you the same number.
a target plant stand density per square foot. You can get an idea by
looking at Ropintheweb’s seeding rate information at http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex81?opendocument#targetlook.
the seedling mortality. For example, I use four percent mortality on wheat
and barley for the farms I work with based on experience. You may see more
or less mortality depending on your seeding practices.
the numbers in the formula to determine your seeding rate (lbs/ac).
Here’s the formula: seeding
rate (lb/ac) = desired plant population/ft² x 1,000 K wt. (g) ÷ seedling
survival rate (in decimal form such as 0.90) ÷ factor of 10.4
So if your 1000 kernels of seed weighed 35 grams and you
want a stand of 30 wheat plants per square foot, and you expect 90 percent
seedling survival, the actual calculation would look like this:
30 plants/ft² x
35 g ÷ 0.90 ÷ 10.4 = 112 lb/acre seeding rate.