Excess nitrogen may decrease maize grain yields when water is limited
Year: 2026
Type: article
Abstract: The effects of nitrogen (N) on crop growth when water is limited are unclear in the literature. Using maize as a model system, a field study with two levels of water (100% and 70% plant evapotranspiration) and six levels of N availability (50 – 327 kg N ha-1 as the sum of fertilizer N, irrigation water N, and soil residual inorganic N) was conducted in the US Great Plains Region from 2021 – 2023. Maize grain yield and aboveground biomass increased with N availability with full water, but excess N was detrimental when water was limited. Additionally, excess N depressed maize root biomass relative to moderate N availability when water was limited. Maximum grain yield was achieved with an average of 31% less N under limited water relative to full water. Maximum grain yields with limited water were 36%, 59%, and 30% less than full water for the 2021, 2022, and 2023 growing seasons, respectively. The 2023 season had lower fertilizer N inputs due to residual N accumulation from previous years, yet a yield reduction at the higher N availabilities was still observed in the water limited treatment. Maize N uptake increased with N and was greater with full water. High N uptake, however, was not only uncoupled with and, thus, not co-limiting with water, but depressed grain yield and biomass. Adjusting N inputs based on soil N availability and yield potential is necessary to maximize yields and resource use efficiency and will become increasingly important as water limitations become more common.
Source: Agricultural Water Management
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,070
Awards: G142196459, G5597448222, G8858358763
OpenAlex ID: W7162510068