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

1

1

1

1

1

1 1

1

1