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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Publications at this Location » Publication #412877
Research Project: Agricultural Management for Long-Term Sustainability and Soil Health

Location: Soil Management and Sugarbeet Research

Title: Side-dress applied ESN reduces N2O compared with single urea application for irrigated corn

Author
item Del Grosso, Stephen
item Delgado, Jorge
item Stewart, Catherine

Submitted to: Soil Fertility Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/4/2024
Publication Date: 3/4/2024
Citation: Del Grosso, S.J., Delgado, J.A., Stewart, C.E. 2024. Side-dress applied ESN reduces N2O compared with single urea application for irrigated corn. Soil Fertility Conference Proceedings. 20:51-56.

Interpretive Summary: Enhanced efficiency fertilizers may reduce soil nitrous oxide (N2O) emissions while maintaining or increasing crop yields. However, further increases in N fertilizer efficiency may be attainable with a starter fertilizer application followed by side dressed ESN. ESN is a type of enhanced efficiency fertilizer designed to slowly release nitrogen (N) and improve synchrony between nutrient supply and plant N demand. We monitored soil N2O using surface chambers from three N treatments (202 kg N per hectare single application of urea, 34 kg N per hectare starter urea combined with 168 kg N per hectare side-dressed ESN, and a 0 N control) to determine their effects on per unit area and yield scaled emissions from a no-tilled soil under irrigated, continuous corn production for three years. Average annual cumulative emissions were 1.4 kg N per hectare for the urea treatment, 0.8 kg N per hectare for starter urea with side-dressed ESN, and 0.3 kg N per hectare for the control. Average annual yield scaled emissions were 0.13 kg N per Mg of grain for the urea treatment, 0.08 kg N per Mg of grain for starter urea with side-dressed ESN, and 0.05 kg N per Mg of grain for the control. These results provide evidence that side-dressed ESN combined with starter urea application is a reliable way to decrease area and yield scaled N2O emissions from irrigated no till corn.

Technical Abstract: Enhanced efficiency fertilizers (e.g., ESN poly coated urea), may reduce soil nitrous oxide (N2O) emissions while maintaining or increasing crop yields. However, further increases in N fertilizer efficiency may be attainable with a starter fertilizer application followed by side dressed ESN. We monitored soil N2O using surface chambers from three N treatments (202 kg N ha-1 single application of urea, 34 kg N ha-1 starter urea combined with 168 kg N ha-1 side-dressed ESN, and a 0 N control) to determine their effects on per unit area and yield scaled emissions from a no-tilled clay loam soil under irrigated, continuous corn production for three years. Average annual cumulative emissions were 1.4 kg N ha-1 yr-1 for the urea treatment, 0.8 kg N ha-1 yr-1 for starter urea with side-dressed ESN, and 0.3 kg N ha-1 yr-1 for the control. Interannual variability was large for the urea treatment, ranging from 0.8 to 2.0 kg N ha-1 yr-1, and minimal for starter urea with side-dressed ESN (0.7 to 0.9 kg N ha-1 yr-1), and the control (0.27 – 0.3 kg N ha-1 yr-1). Average annual yield scaled emissions were 0.13 kg N Mg-1 yr-1 for the urea treatment, 0.08 kg N Mg-1 yr-1 for starter urea with side-dressed ESN, and 0.05 kg N Mg-1 yr-1 for the control. Yield scaled emissions showed similar inter-annual variability patterns as observed for unit area. These results provide evidence that side-dressed ESN combined with starter urea application is a reliable way to decrease area and yield scaled N2O emissions from irrigated no till corn.