By this time of year, most of you have purchased the canola seed varieties to grow this season. As we get closer to actual seeding dates, read these tips to help ensure what you’re doing at planting time is a good foundation for a successful crop.
Don’t set canola seeding depth too deep.
Remember, canola seed is best planted at 3/4 to 1 1/4 inches deep. Any deeper, and you risk a reduced stand count. Unlike other crops, canola lacks the ability to push out of the ground when it’s planted too deep, which is also why soil crusting can result in reduced canola stands.
Calculate canola seeding rate.
Canola seeding rates have become more important as growers look at ways to minimize inputs and maximize profit. Typically, the plan is to grow 7 to 10 plants per square foot. To determine your canola seeding rate, be aware of the seed size of the varieties or lots you are planting. This information is available on the seed tag on the canola bag.
The formula below is used by the Canola Council of Canada to calculate the proper seeding rate.
Canola Seeding Rate (lb. /ac.) = ((DESIRED PLANTS/FT2 x 43,560)/SURVIVABILITY RATE)/
SEEDS PER LB.
- Take your desired plants per sq. ft. (in this example our desired plants per sq. ft. is 8) and multiply by 43,560 = 348,430.
- Divide 348,430 by the estimated survivability (in this example we are assuming a survivability of 80%) by .80 = 435,538.
- Refer to your canola seed tag and find the seeds per lb. (in this example our seed tag shows 88,260 to 91,260 seeds per lb. and we will estimate an average of 89,760 seeds per lb.) Divide 435,538 by 89,760 to get a seeding rate of 4.85 lbs./ac.
Wait for the right soil temperature.
Canola seed can germinate at 37°F. However, uniform emergence requires temperatures of at least 50° F. When soil temperature hovers in the low 40’s, emergence takes 17-21 days. When soil temperature is in the low 50’s, emergence takes only about 10 days.
Review canola fertilizer recommendations.
Proper crop nutrition is key to optimizing yield. In particular, nitrogen, phosphorus, potassium and sulfur can all be yield-limiting factors. This means when you are short on one nutrient, it creates a yield-limiting factor that over-fertilization by another nutrient will not correct.
Don’t skip sulfur.
Canola takes up sulfate sulfur from the soil. This means that elemental sulfur has to first break down into a sulfate form before the plant can use it. If you use elemental sulfur, do so in conjunction with sulfate sulfur. The most commonly used sulfate sulfur product is ammonium sulfate. Because of its high nitrogen content, this product should be broadcast and not used in-furrow.
Lack of sulfur in canola can mean the difference between having a good crop and having no crop at all. Unfortunately, assessing sulfur requirements by soil testing is highly inaccurate and should be used only as a guideline. Current tests overestimate available sulfate-sulfur. Growers should also consider other crops in their rotation that may be high users of sulfur as these crops will further deplete levels.
Broadcast Seeding Canola – is it right for you?
Growers in northeastern North Dakota and northwestern Minnesota are often concerned with the condition of their fields when spring arrives. Will fields be dry enough to plant in a timely matter? If spring is late, cool and wet, what options are there for seeding canola utilizing non-traditional methods? If fields are not accessible with a drill, are there other methods to seed canola? The answer is yes, but multiple factors need to be taken into account before making planting decisions.
Broadcasting canola seed through a floater is the most common practice to utilize if the ground is too wet to seed by traditional means.
If you plan to broadcast seed, take these additional tips into consideration:
- Take your time and avoid rushing
When proper placement with a drill is not possible, broadcast seeding canola is a last resort to get the canola crop planted. Growers should wait until later in the season to utilize this option when time has run out to allow the fields to dry in the appropriate planting window. Warmer soils allow for a more rapid germination and better stand establishment of the seedlings with less risk of death.
- Increase Seeding Rates
Growers utilizing this method should increase their seeding rates as survivability and germination of broadcasting canola could be lower compared to traditional seeding methods. Increasing the seeding rate can compensate for this and allow the grower to maintain plant populations at an optimum level for yield.
- Modifying Fertility Recommendations
Fertility can be something to think about, especially if broadcasting phosphorus at the same time. Utilizing a spreader that has multiple bins to keep the seed and fertilizer separate is optimal. Increasing the phosphorus is recommended since the application method is through broadcast means and not directly in-furrow with the seed, as phosphorus does not move within the soil.
- Residue Management
Fields with a high amount of trash or residue would not be ideal for broadcast seeding as seed to soil contact is important for successful germination. This can be mitigated with cultivation or harrowing, but if neither is possible, then broadcast seeding is not a good option. Seed can germinate in residue and because it is not anchored, the plant can dry up or blow away in the wind thus reducing a viable stand.
- Incorporation is Key
Harrowing or shallow cultivation would be recommended to increase seed to soil contact thus increasing germination and survivability. Beware of creating piles from trash or compacted soil as this could create issues for the seed trying to germinate and survive.
- Crop Insurance Implications.
Reviewing the previous tip, incorporation is mandatory for Crop Insurance coverage of the canola crop.
How deep should canola be seeded to hit moisture?
Moisture is extremely important for canola to germinate. However, making the decision to seed too deep because of dry conditions can create the same problem that a grower is trying to avoid – reduced plant stand/population.
Canola does not have the same capabilities as corn and soybeans to push their cotyledons to the soil surface from deeper than a 2-inch depth. Be cautious, especially early in the season, when soils are cool. It is recommended to wait for rain before seeding or to keep seeding depth shallow to allow for good germination when rain comes. If soil temps are warm, seeding dates are getting pushed, and the grower is planning to seed deeper to reach moisture, the seeding rate should be increased to help with seed survivability.
As we head into seeding, please remember to be smart, safe and aware of those around you when operating equipment.