Nitrogen Fertilizers Technologies for Corn in Two Yield Environments in South Brazil

Area of Science:

• Agricultural Science
• Soil Science
• Agronomy

Background:

• Nitrogen use efficiency (NUE) in corn is critical to minimize economic and environmental impacts from ammonia volatilization (NH3-N).
• Understanding nitrogen fertilizer behavior in different soil types is essential for optimizing crop production and reducing N losses.

Purpose of the Study:

• To evaluate various nitrogen (N) fertilizer technologies for corn production.
• To characterize N sources, quantify NH3-N volatilization losses, and assess impacts on nutrient concentration and corn yield in clayey and sandy soils.

Main Methods:

• Field experiment comparing a control with no N topdressing, conventional N sources (urea, ammonium sulfate, ammonium nitrate + calcium sulfate), and enhanced-efficiency fertilizers (urea treated with NBPT + Duromide, urea formaldehyde, polymer-coated urea + urea with nitrification inhibitor).
• Measurement of NH3-N volatilization losses.
• Analysis of nutrient concentration and corn yield in clayey and sandy soils in South Brazil.

Main Results:

• Ammonia volatilization losses reached up to 46% of applied N with urea.
• Nitrification inhibitor (NI) addition to urea increased NH3-N volatilization by 8.8% (clayey) and 23.3% (sandy) compared to urea alone.
• Clayey soil showed 38.4% greater responsiveness to N fertilization than sandy soil.
• Ammonium sulfate and ammonium nitrate + calcium sulfate reduced NH3-N emissions by 84% and 80% respectively, compared to urea, and increased corn yield in clayey soil.

Conclusions:

• Conventional fertilizers like ammonium sulfate and ammonium nitrate + calcium sulfate are effective in reducing ammonia volatilization and improving corn yield, particularly in clayey soils.
• Enhanced-efficiency fertilizers, including those with nitrification inhibitors, did not consistently reduce N losses and, in some cases, increased volatilization.
• Soil type significantly influences N fertilization response and N loss pathways, highlighting the need for tailored fertilizer strategies.