One thing we can be certain of when it comes to the spring seeding season is that nothing is certain; every spring is unique and brings its own challenges. Early spring 2016 was warm and dry; we were well on our way with seeding before the end of April and wondering if anything was going to germinate. This year with all the reserve moisture from last fall plus all the spring rain and snow we’ve received already, we’re wondering if we’ll ever be able to get into the fields. Add on top of that the number of acres left to combine and producers are starting to explore other seeding options to speed up that process.
Broadcasting canola is used to some extent each year; not many other options get so many acres seeded as quickly. Keep in mind however, that consistently successful canola crop stand establishment generally comes when seed is drilled ½ - 1” deep into moist soil and lightly packed; broadcasting seed should be considered a last resort. If you’re thinking about broadcast seeding your canola this year, whether via floater, valmar or spin spreader, here are some pointers from the Canola Council of Canada you’ll want to consider:
- Seed Rate – Seed germination and survivability decreases significantly when broadcast seeding canola so I wouldn’t recommend seeding less than 5 lbs/acre.
- Phosphorus – Canola requires early access to phosphorus to get it going; you may want to increase your rate of phosphorus fertilizer (especially in fields with moderate to low soil levels) to improve proximity of available P to each seed.
- Nitrogen – Plan on increased loss of nitrogen due to leaching or denitrification in water logged soils. Increasing your applied rate is one strategy, or you could look at some of the nitrogen stabilizer products that are available.
- Crop Residue – As with any seeding operation, success requires good soil to seed contact. Heavy residue increases risk when broadcasting because the seed has a difficult time getting down to the soil. Cultivating or harrowing can help, however if the field is too wet it can also make the problem worse by causing soil to crust and creating lumps of residue.
- Cultivate or Harrow – Lightly cultivating and harrowing after broadcast seeding canola is key to success as it improves soil to seed contact. Be careful when considering how deep to cultivate; the rule of thumb is the seed ends up about half as deep as you cultivate (each time you go over the land the seed will get deeper). Ensure the seed ends up in enough moisture for it to germinate and set roots.
- Weed Control Timing – Canola seed close to the soil surface is susceptible to herbicide. Avoid a post-seed pass of glyphosate on broadcast seeded Liberty Link or Clearfield canola as there will always be some seed at or very close to the soil surface.
- Reset Expectations – Broadcast seeded canola generally yields less than drill seeded canola. You will also have to prepare for more difficult timing decisions when it comes to weed control, fungicide and swathing.
Broadcast seeding may be your best option to get all the acres of canola you want to seed this year in the ground on time. As with anything though, knowing your risks and how to mitigate them will help bring success.