Field-level comparison of nitrogen rates and application methods on maize yield, grain quality and nitrogen use efficiency in a humid environment

ABSTRACT

Appropriate nitrogen (N) management practices are of critical importance in improving N use efficiency (NUE), maize (Zea mays) yield and environmental quality. A six-year (2005–2010) on-farm trial was conducted in Ottawa, Canada to assess the effects of N rates and application methods on grain yield and NUE. In four out of the six-year study, grain yield increased by 60–77 kg ha⁻¹ by sidedress, compared to 49–66 kg ha⁻¹ for each kg N ha⁻¹ applied at preplant. Grain yield response to N between the two strategies was similar in the other growing seasons. Sidedress strategy required 15 kg N ha⁻¹ less of the maximum economic rate of N (MERN) than preplant application. Our results indicate that sidedress application of 90–120 kg N ha⁻¹ with a starter of 30 kg N ha⁻¹ resulted in greater yield, grain quality and NUE than preplant N application in this cool, humid and short growing-season region.

KEYWORDS:

• Nitrogen
• plant physiology
• yield
• soil fertility
• nutrient uptake

Acknowledgments

We would like to acknowledge D. Balchin, L. Evenson, U. McKim and S. Patterson of AAFC technicians for their excellent field and laboratory assistance.

Funding

This study was partially funded by the AAFC peer-reviewed project #71. AAFC-ECORC contribution No. 13-499.