Work

Dissolved nitrous oxide in subsurface drainage under stacking split nitrogen management and cereal rye cover cropping

Year: 2025

Type: article

Abstract: Indirect greenhouse gas emissions are a major source of uncertainty in global inventories. The contribution of dissolved N 2 O (dN 2 O) to indirect emissions is poorly understood, especially considering losses of dissolved gases that stem from subsurface agricultural drainage in nitrogen (N)-intensive corn ( Zea mays L.) systems. To better quantify the impacts of recommended management on drainage losses of nitrate (NO 3 - ) and dissolved gases, water quality was monitored during the growing season at replicated drainage plots in Illinois, USA. Four treatments were tested: pre-plant N application (224 kg N/ha with 60 % fall + 40 % preplant); split-N application (224 kg N/ha with 40 % preplant + 60 % side-dress); split-N + cereal rye ( Secale cereale L.) cover crop; and 0 N control ( n = 4). Dissolved N 2 O concentrations ranged from < 8–58 µg dN 2 O-N/L while dissolved methane was consistently low (<3 µg CH 4 -C/L). Environmental factors (temperature, drainage hydrology, soil inorganic N status) and N application events influenced dN 2 O concentrations and losses. Cumulative dN 2 O and NO 3 - loads followed the same trend: pre-plant N > split N > split + cover crop > 0 N control. The split N + cover crop treatment had a significant reduction in both NO 3 - load and dN 2 O concentration compared to pre-plant N application, highlighting the effectiveness of integrated management practices in reducing N losses to the environment. Split-N alone, while less effective in reducing losses, improved corn yield and agronomic efficiency, achieving the second lowest emissions factor (EF 5 g ). Future research should explore the long-term impacts of these management practices on cumulative dissolved greenhouse gas emissions to better inform climate-smart strategies.

Source: Agricultural Water Management

DOI: 10.1016/j.agwat.2025.109724

Authors: Luciano Alves Oliveira, Mary E. Foltz, Julie L. Zilles, Laura E. Christianson

Institutions: University of Illinois Urbana-Champaign, Oklahoma State University

Language: English

Topic: Soil and Water Nutrient Dynamics

Subfield: Environmental Chemistry

Field: Environmental Science

Domain: Physical Sciences

SDGs: Climate action, Zero hunger

Open Access status: gold

Estimated APC paid: $3,070