manitoba corn meets 4-r nitrogen management: effects on crop … · 2020. 3. 2. · crop yield and...
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Manitoba Corn Meets 4-R Nitrogen Management:
Effects on crop performance and the environment. C. Cavers*, G. Parent, A. Nelson, J. Heard, S. Sager, K. Rose.
Corn Yields (bu/ac)
Summary
Acknowledgements
Aerial photos
Fall Soil Nitrate-N Levels to 24 inches
Discussion
References
Background
Methodology
Since Manitoba farmers are achieving high yields of corn it is
important to use the 4R Principles for Nitrogen Management –
meaning the application of the Right Source at the Right Rate at the
Right Time and the Right Place to optimize yields through efficiency
and to minimize losses (http://www.nutrientstewardship.com/what-
are-4rs).
This project aims to:
• evaluate previous research on new fertilizer technologies (such
as nitrogen sources and inhibitors and optical sensors) and
established technologies such as side dress placement (Grant el
al, 2012) on corn at sites in Manitoba and Quebec;
• evaluate new nitrogen fertilizer strategies of rate, placement and
use of optical sensors such as the Greenseeker.
Three sites in Manitoba were selected for the trials: Elm Creek (loamy fine
sand); Carman (loamy very fine sand); and Portage la Prairie (clay loam).
The following treatment list was applied to the three corn sites, incorporating
some aspects from each of the 4R principles – source, rate, time and
placement:
Treatment #1: zero N check
Treatment #2: urea/ESN broadcast/incorporated pre-plant @ 60 lb N/ac
Treatment #3: urea/ESN broadcast/incorporated pre-plant @ 120 lb N/ac
Treatment #4: urea/ESN broadcast/incorporated pre-plant @ 180 lb N/ac
Treatment #5: urea broadcast/incorporated pre-plant @ 120 lb N/ac
Treatment #6: UAN banded @ stage V6-V8 @ 60 lb N/ac
Treatment #7: UAN banded @ stage V6-V8 @ 120 lb N/ac
Treatment #8; UAN banded @ stage V6-V8 @ 180 lb N/ac
Treatment #9: urea broadcast @ stage V6-V8 @ 120 lb N/ac
Treatment #10: urea treated with Agrotain broadcast @ V6-V8 @120 lb N/ac
All sites were responsive to added nitrogen fertilizer. Visual and measured
factors were able to distinguish the check plots (and some of the lower N rate
treatments) from the other plots.
The effect of the treatments on yield differed by site. In 2014, heavy rains
impacted the Elm Creek site in late June after the pre-plant treatments but
before the in-crop (V6-V8 stage) treatments were applied. Carman received
more normal amounts and frequencies of rainfall, and Portage experienced
more wet conditions that delayed planting to early June. Weather and soil
moisture data will be examined in greater detail to assess these effects.
Along with corn yield and residual soil nitrogen, factors such as plant height,
SPAD meter and Greenseeker readings and a nitrogen stalk test for corn will
be assessed to determine their ability to predict corn yields in a timely fashion
that will allow for supplemental N fertilizer applications if warranted.
• Given this is Year 1 of a 3-year project in partnership with Quebec locations,
we expect some trends to change over time with additional data and more
thorough statistical analyses.
• Comments and suggestions for improvement are welcome.
• Looking for an unfertilized site on heavier ground for 2015 – any
suggestions???
The authors thank the cooperating producers for providing land and
equipment to conduct these trials: D. Enns (Elm Creek) and M. & J. Krahn
(Carman).
Thanks to M. Cott and K. Rose of the Manitoba Corn Growers Association for
assisting in the set up and monitoring of these trials.
Thanks to Jeff Kostiuk of MAFRD for taking the aerial photos of the sites.
Grant, C. A., R. Wu, F. Selles, K. N. Harker, G. W. Clayton, S. Bittman, B. J.
Zebarth, and N. Z. Lupwayi. 2012. Crop yield and nitrogen concentration with
controlled release urea and split applications of nitrogen as compared to non-
coated urea applied at seeding. Field Crops Research 127, pp. 170-180.
Figure 1. Broadcasting pre-plant
treatments.
Figure 2. Banding UAN
treatments at corn stage V6-V8.
Figure 3. Measuring corn
plant height.
Figure 4. Measuring
chlorophyll content with a
SPAD meter.
Figure 6. Elm Creek. Figure 7. Carman. Figure 8. Portage.
Figure 12. Mean residual fall soil nitrate-N levels by treatment
(lb/ac; all sites) – no statistical analyses to date.
Controlled release fertilizer and delayed applications appeared to protect nitrogen
to the point where it was not used by the plant.
Aerial photos taken July 23, 2014 using UAV (unmanned aerial vehicle)
technology show some visual differences among the plots either due to
treatments or variable site conditions (Number 1’s indicate check plots).
Figure 5. Measuring differences in
plant biomass among treatments using
a Greenseeker reflectance meter.
LSD 0.05
LSD 0.05
LSD 0.05
Figure 9.
Treatment
Figure 10.
Treatment
Figure 11.
Treatment
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