Demonstrating 4R nitrogen management principles for canola

Project Summary

A field trial was established near Indian Head, Saskatchewan to promote 4R nitrogen stewardship and to demonstrate the overall canola response to nitrogen fertilization along with the relative performance of nitrogen fertilizer management strategies where the forms, timing of application and placement were varied.

The weather was dry with below average snowfall the preceding winter and only 61% of the average growing season precipitation.

For the first objective, 0x, 0.5x, 1.0x, and 1.5x of a baseline rate of 145 kg nitrogen/ha (soil residual plus fertilizer) was supplied as side-banded urea. Data collection included NDVI, leaf chlorophyll (SPAD) measurements, and yield, all of which were affected by nitrogen rate in a similar manner. The yield increase with nitrogen was 133% over the control with similar yields between the 1-1.5x rates. Focussing on nitrogen management strategies, the demonstration included four forms (untreated urea, Agrotain, SuperUrea, and ESN) and three timing/placement options (fall surface-broadcast, fall in-soil band, and side-band). Averaged across forms, yields with fall surface-broadcast applications were 9% lower than with either fall in-soil or side-banded nitrogen. Yields with were similar for fall banded versus side-banded nitrogen.

Regarding forms, all performed similarly under the conditions encountered when averaged across timing/placement methods. Specifically with fall surface-broadcast placement, yields with SuperUrea tended to be higher than with either fall broadcast urea or Agrotain and did not differ from most individual treatments where nitrogen was banded beneath the soil surface.

Nitrogen fertilizer management is sensitive to weather and environmental conditions; therefore, the actual results that producers might experience with these strategies can vary greatly. In general terms, soil testing is advised to account for the inherent fertility of the soil and better determine appropriate fertilizer rates. Side-banding continues to be recommended as a safe and effective practice that will provide consistent results over a broad range of environmental conditions. In the current demonstration, fall in-soil banding was also highly effective and, although the benefits can vary depending on the specific conditions encountered, enhanced efficiency fertilizer products can improve performance particularly with potentially risky practices such as fall-surface broadcasting.

Funding acknowledgement

This project was supported by the Agricultural Demonstration of Practices and Technologies (ADOPT) initiative under the Canada-Saskatchewan Growing Forward 2 bilateral agreement.