Agronomy Agronomic Articles

Killing with Kindness

Are You Killing Canola Seed With Nitrogen Placement? - Cutting Edge, Spring 2021

You’ve mindfully considered all of the different aspects of your seeding season.  You’ve invested great amounts of money in your seeding equipment and your inputs. You are itching to get into the tractor and start seeding.  As is the case every year, you know that how you approach getting your valuable seed and nutrients into the ground is the foundation which your crop, and, ultimately, your livelihood rely upon.  This is the part of the equation that you can control. However, Mother Nature has her own agenda.

As part of this strategy, you pay special attention to principles that you’ve adopted over the years. This may include: getting going as quickly as possible in the spring, or seeding a certain crop before another crop. You may have also borrowed principles from others when they make sense, as to avoid learning everything “the hard way”.  Armed with these principles (and if Mother Nature doesn’t interfere too greatly) you are confident that you are on the road to victory!  BUT, times change, conditions change, and sometimes principles need to be scrutinized. Is there one critical part of the equation that you are missing that may be neutral in ideal conditions, but detrimental, sometimes seriously detrimental, in a dry year?

The forth principal of Nutrient Stewardship states: “Right Place - Address root-soil dynamics and nutrient movement, and manage spatial variability within the field to meet site-specific crop needs and limit potential losses from the field.” 

How does this principle apply specifically to you?
What could be the possible implications of not paying attention to all of the different,
very real parameters that are in play, including the root-fertilizer dynamic?

In real terms, if you light a match too close to your fingers…they will get burned!  The laws of nature are immutable.  Failure to comply will inevitably result in predictable outcomes.  If you apply high rates of nitrogen close to your seed, you are increasing its risk of mortality.  This is a fact.

Over the past years, the Bourgault Agronomy Team has observed this recurring pattern in their trials.  Trials established in 2020 near St. Brieux, SK tested how the placement of nitrogen relative to the seed affected canola. Two treatments were established to make the comparison: 

1.   140 lb of nitrogen in a mid row band at 6" to the side and 1" below the seed;

2.   140 lb of nitrogen in a side-band at 1.5" to the side and ¾" below the seed.

The plot size was 30' by 400' and all treatments were replicated 3 times.  The center 25' were swathed and harvested where yield was determined via a weigh wagon.  Samples were taken from every treatment and sent away for analysis of moisture and dockage to calculate an equalized yield.

 A leading L7550 air cart coupled with a 30' TriMax™ Triple-Shoot drill at 12" spacing was used for both treatments.  The drill was equipped with PLDS™ (ParaLink Dual Shank™) Openers, along with MRB® (Mid Row Bander®) Fertilizer Applicators.  When nitrogen was placed in the side-band, the MRB® Fertilizer Applicators were locked up.  When nitrogen was placed in the mid row band, the banders were engaged. 

The results showed a large difference in plant stands and maturity, even though there was little difference in yield between the treatments. This can be attributed to canola’s ability to fill in space by branching out and creating yield from those branches, given it has enough moisture and time to do so.

The treatment with nitrogen in the mid row band had a significantly higher plant stand than the treatment with nitrogen in the side-band.  Both treatments were seeded at 10 seeds/ft2, meaning that the mid row band treatment had an 86% plant establishment versus the side-band treatment which had a 49% plant establishment. 

All treatments were applied on the same day and with the exact same opener, same starter fertilizer rate, soil moisture, weather, insect pressure and disease pressure.  The only difference was nitrogen placement.

The side-band treatments were swathed between 3 and 6 days later than the treatments with the nitrogen placed in the mid row band.  The extra time was required for the branches to develop, fill out and mature before harvesting in order to capture the yield potential.  In some years this delay could be the cause for not getting the crop off before a major snow fall, or having high green counts because the seed didn’t dry down enough before a heavy frost.

Nitrogen in Mid Row Band

(picture taken July 8th, 2020)

Nitrogen in Side-Band

(picture taken July 8th, 2020)

The reduction in plant stand establishment is very similar to what we have seen over the past several years of doing these side-by-side comparisons.  Trials were conducted in both very wet and very dry springs over the past 5 years in the same way that the 2020 trials were conducted.  Yields throughout the testing years were similar between placements, but maturity was always delayed with lower plant stands.

The average plant stand establishments in the 4 years of testing:
1.   Nitrogen in a side-band – 4.6 plants/ft2
2.   Nitrogen in a mid row band – 6.8 plants/ft2

On average, over these four years of testing, being that 10 seeds/ft2 were sown each year, the side-band placement of nitrogen meant a 46% plant establishment and the mid row placement of nitrogen meant a 68% plant establishment.  Plant stands taken at the 2-3 leaf stage indicate that the canola seeds never did emerge.  This suggests that the canola seed was hurt or killed by the close placement of nitrogen, reducing the overall emergence numbers.

If a Producer wants to reduce seed costs by targeting a plant stand of 4.6 plants/ft2, the seeding rate could be reduced by 32%, and the seed protected by placing nitrogen in a mid row band versus in a side-band.  A much better environment has been established so a greater plant survivability can be expected.  The 32% reduction in canola seed at a cost of $70/acre would provide a savings of $22.40/acre. 

Variable Rate = Variable Risk?

As applied rates of nitrogen continue to rise, and as variable rate fertilizer technology increases in popularity, prescription maps will be calling for surprisingly high rates in different areas in the field. If all the N is being placed in a side-band, the risk of hurting canola seed will increase significantly as the rate is dialed up.

Grow Canola - Don't Smoke it!

By following the 4R Nutrient Stewardship principles you can protect against fertilizer loss and with a bit more vigilance, you can protect your seed as well. The last thing you want is for your expensive fertilizer to kill your expensive seed.

Reduce your risk, reduce your input costs and increase the productivity of every canola seed with properly placed nitrogen.

Try this simple test on your farm to verify if your canola is experiencing N damage.  
During seeding, shut off the nitrogen for a short distance of approximately 50'.  Mark out the area with no nitrogen, and come back at the 2-3 leaf stage of the crop.  Do a plant count in the area where the nitrogen is on, and do a plant count where the nitrogen is off.  A comparison of the two counts will give a good indication if there is damage being done to your plant establishment or not.