When seeding canola, slow and steady wins the race.
Farmers who open up the throttle wider to get more acres seeded quicker this spring should keep in mind that lower speeds pay off in more consistent seeding depth, according to Jim Bessel, a senior agronomy specialist with the Canola Council of Canada.
With a 40-foot air seeder on a quarter section field, 66 passes are needed to cover the ground. At a half-mile per pass, that’s 33 miles covered.
“At four miles per hour, that 33 miles takes me eight-and-a-quarter hours. If I bump it up to five miles an hour, that 33 miles takes me 6.6 hours,” said Bessel in a presentation to Canola College in Manitoba this month.
“So that’s a difference of 1.65 hours. How much is that worth to me from a seed placement perspective?”
A study under real, in-field conditions showed that the average depth of the canola seed coming out the back of the seeder showed more variation as the speed was increased.
At three miles per hour, the seed stayed within the optimum zone of a half-inch of depth, but the inconsistency rose the further the throttle was opened up. At four miles per hour, it ranged from half an inch to 1.75 inches.
“I always hear, ‘That damn seed wasn’t any good!’ Well guys, when you’ve got a range here, which at five miles an hour goes from a quarter-inch to three-and-a-quarter inches, that’s a hell of a long distance for that little food reserve in the seed to give you a bang for your dollar at the end of the day,” said Bessel.
That said, the best speed depends on the type of seeder used. As long as the seed is placed accurately in terms of depth and distance from the fertilizer granules, any speed is fine, he added.
For those who can’t afford to slow down because they are pressed for time to cover the ground, increasing seeding rates may help preserve stand uniformity and plant population levels despite the increased losses to mortality.
But the extra costs don’t stop there, Bessel added. Extra herbicide and pesticide applications may figure into the calculation for speed demons. Also, higher speeds result in more soil disturbance, and the extra aeration may lead to moisture losses.
Other measures to ensure consistent seeding depth include checking tire pressure, levelling the drill from side to side and from front to back, monitoring seeding depth when moving from field to field, and taking care before the season to replace worn openers.