Canola Agronomy for Low to Intermediate Rainfall Dryland
Under 17 Inches of Annual Rainfall – Summer Fallow Production
Advances in winter canola varieties, combined with improved planting techniques, make winter canola an attractive choice for summer fallow dryland production. In areas where winter survival rates are lower, spring canola can be grown if the rainfall pattern favors a spring crop.
Research has shown wheat yields improve when canola is added to the rotation.
Winter Canola vs. Spring Canola
- If Stephens wheat performed well on your farm, winter canola should do well.
- Spring canola can be successfully grown in areas where winter survival is low and the rainfall pattern favors the spring and summer months.
General Seeding Tips for Canola
- Canola seed is small and must be planted into shallow moisture to germinate.
- Consistent planting depth is critical. Adjust your drill and reduce speed so seeding depth is between 0.5 and 1 inch.
- Canola seed can be successfully broadcast in the right conditions. If high moisture prevents conventional seeding, broadcast seeding can be an option..
- Air seeders make it easier to regulate the amount of seed planted.
- The cross slot drill is successful for planting canola in high-residue fields, particularly when accompanied by hydraulic control for planting depth.
- Canola seed flows like water. If you are using a conventional grain drill, monitor your seeding rate carefully. Consider taping off every other indent in each seeding disk.
- You can use a bulking agent to regulate the amount of seed planted. A modest amount of 11-52 fertilizer can be used, but banding high rates of fertilizer next to the seed will hurt germination.
- Don’t mix varieties. If you are planting generic and specialty varieties in different fields, clean your drill when you switch canola varieties. Generic seed will contaminate your specialty seed, causing you to lose your premium.
Seeding Winter Canola
- A summer fallow regime gives you greater timing flexibility. Planting dates can be as early as late June to insure the seed has moisture to germinate.
- Seeding rates generally range from 2.5 to 4 lbs./acre.
- Winter varieties, such as Amanda, can be planted as early as April or May. They will not bolt (go to seed) until they are vernalized over the winter. These varieties can even be grazed during the summer.
- Plant when the forecast indicates moderate temperatures for the next 7 days. It is best if the temperature stays below 90 degrees Fahrenheit until the canola has its first set of leaves.
- Canola plants should be at least at the four-leaf stage (dinner plate size) before the first hard frost. Winter canola should generally be planted before early September, unless you farm in a long-season area.
Seeding Spring Canola
- Plant with the same timing as spring wheat.
- Seeding rates range from 4 to 7 lbs./acre, with 5 lbs. being a typical figure.
- Modern spring varieties are more vigorous and generally more resistant to frost damage. If you get an early frost, flowering plants will usually recover and keep on blooming.
General Fertility Guidelines for All Canola
- Use the following formula to estimate your fertilizer requirements for canola: Nutrient Application = (Yield Goal x Per Unit Recommendation) – Soil Contribution.
- Nitrogen: Recommendations range from 6 to 10 lbs. of available nitrogen per 100 lbs. of expected yield. Heavy residue from the previous grain crop will increase the required nitrogen.
- Phosphorous: Recommendations are generally around 1 lb. of available phosphorous per 100 lbs. of expected yield.
- Potassium: Most western soils are high enough in potassium that an additional application does not produce a yield response. Consult with your agronomy professional for potassium recommendations.
- Sulfur: Canola responds well to sulfur. Recommendations are typically in the range of 1 to 2 lbs. per 100 lbs. of expected yield. Many growers apply a minimum level of 20 lbs. of sulfur, even if the soil test shows adequate levels.
- Boron: Thus far the only micronutrient shown to produce a yield response in canola. Consult with your agronomy input provider for Boron recommendations for your area.
- Canola emergence can be hindered by banding nitrogen too close to the seed.
Fertility Guidelines for Winter Canola
- In dryland areas, each 10 bushels of wheat per acre can produce about 300 to 400 lbs. of canola. For example, if you produce 60-bushel wheat you can expect approximately 2,100 lbs. of canola. If you are new to growing canola, use this as starting point to estimate your yields for fertility management.
- When planting in low-rainfall areas in July or August, it is important to do a split application of nitrogen between the fall and the spring. Too much nitrogen availability in the summer and fall will stimulate vegetative growth and can depress winter survivability.
- If you have problems managing the low seeding rate through your planter, consider using 11-52-0-0 fertilizer as a bulking agent. The nitrogen content is low enough that seed damage is unlikely.
Fertility Guidelines for Spring Canola
- Depending on rainfall and soil type, spring canola yields can range from 1,200 to 2,500 lbs./acre or more. You can estimate your canola yields based on your spring wheat production. For each 10 bushels of spring wheat, you can expect 300 to 400 lbs. of canola. For example, if you produce 50 bushels of spring wheat, you can estimate your canola production will be about 1750 lbs./acre.
- Fertilizer can be applied and incorporated, as with other crops, but do not band significant quantities of nitrogen close to canola seed.
- Split applications of nitrogen have not shown a response in spring canola, but nitrogen can be foliar applied prior to flowering.
- High residues from the previous crop consume nitrogen. Take this into account when determining your nitrogen needs.
The above canola agronomy recommendations are general guidelines only. For publications that provide more specific information, refer to our canola resources.