PROJECT RESULTS

Optimizing Canola Production:  Fertilization, Crop Protection and Yield Potential

Applicant: 

Dr. Don Flaten
Department of Soil Science
University of Manitoba

Winnipeg, Manitoba  R3T 2N2  Canada

Table of Contents:

• Background and Objectives
• Results and Discussion
• Conclusion

ARDI Project:

#01-508

Total Approved:

$19,500

Date Approved:

February 7, 2003

Project Status:

Completed March, 2005

Background and Objectives:

Imagine that if every time a farmer used a crop input, whether it was better seed, more fertilizer, or more pesticide, they could add the yield increases that are claimed by the researcher, extension specialist or marketer that is promoting the product.  If that were true, nearly every farmer would be able to grow a canola crop of at least 100 bushels per acre.  In reality, of course, although the costs of those inputs stack up end-to-end, the yield increases do not and farmers are well justified in not using every input that appears to make a profit in research trials.

One of the biggest reasons why the results of typical research trials do not translate directly into increased profits and huge overall yields for farmers is that traditional agronomic research, extension and promotional information usually focuses on one input or management practice at a time.  Research trials are rarely set up to measure the interactions among inputs.  In typical, single input experiments we measure the impact of adding one input under conditions where all other inputs are applied at a constant, optimum level.  For example, most nitrogen fertilizer responses are evaluated under conditions where the supply of other nutrients such as P and S are ample, a high yielding variety is planted for all treatments and no expense is spared to protect the crop against diseases, insects and weeds.  At the end of such an experiment, the researcher may show a very attractive rate of return on investment in the N fertilizer, which ignores the yield benefit and input costs that should be credited to the other crop inputs and management practices that set the stage for a large N response.

To learn more about how to translate typical research trials into real life cropping systems, we examined the individual and combined effects of various levels of fertilization, crop protection and genetic yield potential on canola yield, quality and profitability.

Results and Discussion:

As shown in Table 1, the rate of return to low, medium and high input cropping systems varies substantially with growing conditions.  At the Brandon Research Centre in 2001, yield potential was excellent and intensive application of crop inputs resulted in a yield increase of 40 bushels per acre and a substantial improvement in economic margin.  For 2002 and 2003, where yields were limited by adverse growing conditions, the agronomic response was modest and economic response was generally negative.

Table 1.  Yield and economic returns from low, medium, and high crop input packages for Brandon site in 2001, 2002 and 2003 (canola priced @ $7/bu) 

The difference between the yield and economic responses for individual crop inputs and the overall response to those inputs as part of a whole cropping system was substantial (Table 2).  The individual yield responses to improved genetics, aggressive fertilization, and application of a complete set of herbicides, insecticides and fungicides were large.  Each of the individual inputs appeared to increase in profitability; the responses to variety and fertilizer seemed especially profitable.  However, when all the inputs were applied together, the overall yield was significantly less than what might have been expected from adding together the individual yield responses.  And, of greater concern, the difference between the theoretical and actual margins for the high input cropping system was very large, resulting in little improvement to the profit margin, compared to the low input system.

Table 2.  Average benefit of canola crop inputs when yield responses to those inputs are added individually or as a part of a complete cropping system at Brandon in 2001, 2002 and 2003 (canola priced at $7/bu)

* Costs for base yield include preseeding glyphosate, seed, machinery, fuel, repairs and other basic costs.

** The higher expense for the high yielding canola variety was offset by planting at a lower seeding rate than for the medium yielding variety and using less seed treatment.

*** The benefit of the lower seed treatment costs for the high yielding canola variety is included twice in the theoretical addition of input costs, underestimating those total input costs, compared to reality.

Conclusion:

Acknowledgements:

This three-year research project was supported by canola producers in Manitoba and Saskatchewan, plus Manitoba Agriculture’s Covering New Ground Program, the Potash and Phosphate Institute and the Canada-Manitoba Agri-Food Research and Development Initiative.

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