Watch: Sulfur Requirements for High-Yield Canola
Canola and sulfur are both known for their brilliant yellow colour. Since canola has the highest sulfur demand of any crop grown in western Canada, it’s a handy visual reminder that canola requires an ample supply of sulfur. Not just at the early growth stages – but right up until pod fill. And to achieve top yields, it’s important to feed that need.
Canola has unique sulfur requirements
All plants need sulfur for healthy growth and development. It’s essential to production of proteins enzymes and amino acids (like cysteine and methionine). Sulfur is also crucial to photosynthesis – playing a key role in chlorophyll production and detoxification of free radicals.
Flowering plants – especially those used for oilseed production – have much greater need for sulfur than most other crops. And the demand for sulfur is relatively steady throughout the growing season – as opposed to nitrogen which can have peaks and valleys.
In canola, there is a heavy need for sulfur at these key growth stages
+-“Primarily we’re going to see a lot of uptake prior to the flower bud stage. But even after that there is still sulfur required for pod set for grain fill. So sulfur is required season-long,” explains Ray Dowbenko, an independent agronomist and crop consultant. WATCH VIDEO
He points out that canola also has a high nitrogen demand, noting that sulfur facilitates nitrogen usage by the plant.
“If you’re putting on a large amount of nitrogen for your canola and you’re not adding a balanced/adequate amount of sulfur, you’re not getting the full benefit of either (nutrient).” Dowbenko adds.
How much sulfur does canola require?
For every bushel of canola yield, 0.5 to 0.7 pounds of sulfur are required. (The Canola Council of Canada puts that figure as high as 0.8 lb/bu).
To get a 50 bushel per acre canola crop, 25-40 pounds per acre of available sulfur is necessary. If you’re committed to achieving optimum canola yields of 70 bushels, that number can range between 35-56 pounds per acre.
Soil sulfur levels are not uniform
It’s important to realize that plant-available sulfur can vary wildly across a field. One area may only need 10 pounds on an acre while another that is sulfur-deficient may warrant the addition of hundreds or thousands of pounds as part of a renovation. That’s why comprehensive soil testing is necessary for a uniform, high-yielding canola crop.
Choosing your sulfur source
Fifty-six pounds per acre is a lot of sulfur.
To get there through sulfate fertilizers can require high application rates, due to the lower sulfur analysis. You can achieve this through multiple applications of fertilizers containing sulfates spread across the growing season.
Ammonium sulphate (AMS) is popular solution. Yet, at 24% S, you have to put down a heck of a lot of product – which means you have to pay close attention to nitrogen levels, and input costs.
Elemental sulfur fertilizers (ie. degradable bentonite sulfur products) are economical, and can provide a high sulfur analysis (85%-90%), with minimal risk of loss due to leaching.
“If we’re talking about in-season applications, you certainly have to be aware of the growth stage of the crop to maximize the value. (With) a product like an elemental sulfur that has season-long availability, you don’t necessarily have to worry about that,” Dowbenko adds.
When it comes to meeting sulfur demand in canola, you need to be fast out of the gate, but slow and steady can help you win the race.
Remember that visual reminder?
When it comes to a healthy, high-yielding canola crop, don’t forget to think yellow. Talk to your agronomist to discuss your options for an effective and economical season-long sulfur strategy.
A better bentonite sulfur!
Learn how Keg River’s premium degradable sulfurs provide a superior breakdown for optimum season-long availability. [Learn More]
