Agronomy Services Manager Chris Howard Discusses the Importance of Sulphur in Canola Crops

Nutrient management of canola has never been as critical as it is in the 2021 winter crop season. With high wheat yields recorded across the eastern seaboard last year, along with an increase of canola area planted in 2021 on the back of firming world oilseed prices, now is the time to ensure you have a Sulphur management plan in place. High 2020 canola yields and the reduced availability of compound starter products means an early look at supplemental Sulphur products is key to ensure you are not short of this critical nutrient.

Sulphur plays a major role in Nitrogen synthesis for protein production. Canola has a reduced nitrogen recovery efficiency due to its root system, and a high protein component in the range of 20%. Sulphur is the best way to ensure a great return on investment in the rotation when looking to maximise Nitrogen uptake. Some organic Sulphur will be converted to a plant available form throughout the season, however decreased soil temperature and reduced oxygen due to wet conditions during winter will limit the availability of organic Sulphur. Relying on this source of sulphur only would be fraught with danger as crop demand will outstrip supply in most cases.

When making a choice as to what nutrient requirement your crop has in 2021, I recommend the three-point plan for ensuring you meet your crop requirement.

  1. Know your starting Nitrogen and Sulphur levels (establish a baseline).
  2. Measure in crop deep nitrate and sulphur by testing (understand conversion rates).
  3. Know your yield potential (review during the season).

By having a clear plan about how to address the gap between the yield and your soil nutrient levels, the choice of what ratio of Nitrogen and Sulphur to use for the season will be very clear.

For this reason, no two paddocks will be the same, therefore Impact has a variety of products available to fit the results of your canola crop rotation.

PRODUCT

N(Total)

S(total)

S(elemental)

Canola Gold 3312

33.1

12.0

0.0

Canola Gold 4006

39.6

6.0

0.0

Canola Max 15

31.7

14.7

2.7

Canola Max 8

38.6

7.8

1.8

As can be seen above, the choice of sulphur to supply your crop can be made depending on how much and when you need it. Blends are available as both sulphate and elemental, so the choice to have a more immediate release (sulphate) or a more sustained portion of release (elemental) can be made depending on your crop needs.

Yield potential as the growing season progresses should also be considered when determining your nutrient requirements. Do you require early Sulphur and Nitrogen, or would it be beneficial to asses yield as the season progresses and apply a second dose of Sulphur or just a Nitrogen supplementation? Canola can recover from Sulphur deficiency if addressed before stem elongation initiates, so ensure whatever decision and strategy you chose is applied to the paddock before this stage.