Upping your nitrogen game through enhanced efficiency fertilizers and OFCAF support

Our previous blog post discussed the importance of optimizing your crops nitrogen (N) uptake by applying N as and when it’s needed by the crop, using brassica species as an example (Brassica nitrogen dynamics)

For this post, I wanted to highlight a fact sheet produced through Perennia’s On Farm Climate Action Fund (OFCAF) on enhanced efficiency nitrogen fertilizers. These fertilizers are engineered to provide a controlled, slower, release of N that will more precisely meet the demands of your crop.

As a producer, this is an excellent time to trial enhanced efficiency fertilizers as OFCAF could help cover the difference in cost between regular and enhanced fertilizers. Find out more information here.

These enhanced fertilizers have different modes of action that stabilize and reduce N leeching and volatilization so it’s important to choose the right fertilizer based on your specific crop N demands as well as your farm field demands.

These fertilizers are one of many tools to help you dial in your fertility management. Reducing rates, switching from surface to subsurface application, or applying N closer to when maximum crop uptake occurs are some of the other tools that can, and should, be used as needed. Enhanced efficiency fertilizers will have the greatest effect where there is a higher risk of losses such as when surface applying fertilizer or applying in wet areas. Under these conditions they provide insurance against nitrogen losses... Protecting your fertilizer investment.

There’s a wealth information in the fact sheet so give it a read and reach out to your specialist if you want to chat more about N fertility! Also, make sure to apply for OFCAF funding before the deadline of Nov 30^th.

Factsheet: https://ofcaf.perennia.ca/wp-content/uploads/sites/19/2022/10/Enhanced-Efficiency-Nitrogen-Fertilizers.pdf

OFCAF homepage: https://ofcaf.perennia.ca/

Tim Morcom

 

Brassica nitrogen dynamics: Fertility planning and seasonal N carryover

As this season is winding down and planning for next year begins, it’s a great time to consider nitrogen applications for your brassica crops as well as what nitrogen credits are made available to the crop following your brassicas.

There’s tremendous variability in the rates and application methods that growers use. Many fail to maximize the efficiency of their fertilizer by applying it at times when the crop doesn’t need it but weeds will hungrily accept it.

Most brassicas have similar seasonal N uptake demands, as depicted in the graph below (fig 1.), which plots nitrogen uptake over a typical cauliflower growth cycle. You can see that N demand dramatically increases around 25 days after transplanting, and 75% of the plant’s nitrogen needs are during the last half of its lifecycle.

Fig 1. Cauliflower seasonal N uptake [1]

Recent research from Cornell shows that when growers apply the same rate of fertilizer but choose to split-apply their nitrogen instead of only applying pre-plant, average yields increased by close to 5% representing an increase from 32.8 ton/A to 34.2 ton/A ^[2]. Across multiple farms and three years of study, the researchers found a 50:50 ratio of fertilizer application (at-planting : side-dress) produced the greatest yields when the side-dress application was banded at 30 days after planting.

By split-applying your nitrogen, not only are you matching your fertility to the demands of the crop, you are also minimizing the fertility available to your weed bank and reducing losses through leaching. And, by banding your fertilizer, the nutrients in the areas between rows are minimized whilst your brassica crop has maximum availability.

Brassicas, especially cabbage, are excellent N scavengers. This coupled with the fact that much of the plant is left in the field after harvest means that you can expect residual N the following year of up to 10 lb/A. A typical cabbage crop requires 200 lb/A of N over a growing season. After harvest, there is roughly 100 lb/A in the leaves, stump, and roots left on the field. This residue breaks down and is mineralized, ready for plant uptake the following season. Plant available N levels the season following cabbage averaged 8-10 lb/A ^[3]. This might not seem like much, it’s clearly no legume—but it’s definitely worth considering as fertilizer costs steadily climb. 

 

Tim Morcom

 

  

References:

[1] UC Davis, Cauliflower uptake and partitioning, http://geisseler.ucdavis.edu/Guidelines/N_Cauliflower.html#References

[2] Hoepting. C, Understanding Nitrogen Use In Cabbage: New York Study, CCX Cornell Vegetable program, https://rvpadmin.cce.cornell.edu/uploads/doc_857.pdf

[3] Hoepting. C, Understanding Nitrogen Use In Cabbage: New York Study, CCX Cornell Vegetable program, https://rvpadmin.cce.cornell.edu/uploads/doc_857.pdf

 

The On-Farm Climate Action Fund for Nova Scotia and Newfoundland and Labrador is Open!

A new funding program will help farmers receive up to $75,000 in funding when adopting and implementing beneficial management practices (BMPs) that store carbon and reduce greenhouse gases, specifically in the areas of: 

• Improved nitrogen management 

• Cover cropping, and 

• Rotational grazing 

The On-Farm Climate Action Fund (OFCAF) is part of the Government of Canada's Agricultural Climate Solutions, a multi-stream program to help farmers tackle climate change. Perennia Food and Agriculture Inc. is implementing the fund to help farmers adopt these practices in Nova Scotia and in Newfoundland and Labrador.  Training for farmers and agronomists will also be offered over the two-year program, which ends in March 2024. 

For more information on the program or to apply please visit the website ofcaf.perennia.ca.  Deadline for the first intake of applications is July 31, 2022.  

 

Nitrogen Savings in Winter Spinach Production

 By: Talia Plaskett, Protected Crop Specialist 

As summer production of tunnel vegetables slows down, it is time for winter greens to move on into the greenhouse! Spinach, along with a variety of other cool season greens, can be grown in high tunnels throughout the offseason. This allows you to maximize your use of the otherwise empty greenhouse space without cutting into the production of your summer crops.  A recent study done by the Northern New York Agriculture Development Program (NNYADP) examined the effect of nitrogen(N) fertilizer rates on winter-grown, high tunnel spinach production.

A study out of New York examined the effect of nitrogen rates on winter-spinach - photo credit Johnny's Seeds

 In the winter of 2018-2019, they examined the effect of different pre-planting N applications on overall spinach yields. The same N source was used across the four treatments, allowing them to make direct comparisons to yield based on input.  Rates of 0 lbs/ac, 65 lbs/ac, 130 lbs/ac or 200 lbs/ac were applied to their treatment plots about 1 week prior to transplanting the spinach. Plants were seeded in two batches, one on August 27 (early planting) and one September 10 (late planting). These were transplanted into the tunnel on September 21 and October 9, respectively. Yield measurements were based on harvesting the plants at the baby-medium leaf stage at 4 dates.  

When looking at the total yield for each treatment, there was no significant difference between those plots that received 0 lbs/ac and those treated with 200 lbs/ac. Planting date did make a difference to the spinach harvested in the fall and in the winter, where the early planting produced more compared to that of the later planting. Over the course of the season, however, the later planting caught up to the earlier one, to produce similar yields by the April harvest date. The importance of the planting date may depend on when your summer crop is pulled in the fall, and when the subsequent summer crops are started in the spring. If you plan to have your summer transplants started by late winter (February/March), a later planting of winter greens may not have the time to catch up to the production of the earlier planting.  

For more information on the study, check out “Nitrogen Uptake in Winter Spinach”, part of the “Northern New York Agricultural Development Program 2019 Project Report". 

If you are interested in winter greens production, check out the ‘Into the Weeds, Winter Greens Production’ session posted on Perennia’s YouTube channel or reach out to a specialist!