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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Publications at this Location » Publication #428817
Research Project: Improving Understanding of Soil Processes for Making More Informed Agricultural Management Decisions that Increase Agricultural Sustainability in the Central U.S.

Location: National Soil Erosion Research Laboratory

Title: Impacts of hybrid selection and nitrogen fertilization on root-derived carbon inputs in maize

Author
item PEARL, CARSON - Purdue University
item ORDONEZ, RAZIEL - Purdue University
item PRESCOTT, CINDY - Purdue University
item QUINN, DAN - Purdue University
item WILHELM, ROLAND - Purdue University
item Penn, Chad
item JOSHI, BINOD - Purdue University
item RUI, YICHAO - Purdue University

Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2025
Publication Date: 1/7/2026
Citation: Pearl, C., Ordonez, R., Prescott, C., Quinn, D., Wilhelm, R., Penn, C.J., Joshi, B., Rui, Y. 2026. Impacts of hybrid selection and nitrogen fertilization on root-derived carbon inputs in maize. Plant and Soil. https://doi.org/10.1007/s11104-025-08231-7.
DOI: https://doi.org/10.1007/s11104-025-08231-7

Interpretive Summary: Conventional agricultural practices prevent accumulation of soil organic carbon (SOC), which inhibits development of healthy soils. Corn roots have the ability to excrete carbon compounds that can increase SOC, but little is known how crop management, such as nitrogen (N) fertility, can affect that. Bayer tall and short-stature corn was grown in the greenhouse at four different N fertilizer rates, and above and below ground plant biomass was measured, including root C excretions. Short corn produced greater root biomass than conventional tall corn and excessive N fertilizer application reduced the amount of root C excretion, root growth, and microbial biomass. This information will inform growers who want to build soil carbon stocks for improving soil health and resiliency of yields and soil stability.

Technical Abstract: Background and Aims: Intensive agriculture has depleted soil organic carbon (SOC) stocks globally, necessitating the development of effective strategies for its restoration. Recent advances suggest simple carbon (C) compounds, such as root exudates and microbial necromass, are key SOC precursors, yet how management can harness this remains unclear. This study aims to determine how maize hybrid selection and nitrogen (N) fertilization influence root-derived C inputs and soil microbial C cycling. Methods: Bayer tall- and short-stature maize (Zea mays) hybrids were grown in a pot-based experiment in two soil mixes (sandy and loamy), with N fertilization rates of 0, 90, 180, and 270 kg N ha-1. Above- and belowground plant components, root exudation, root biomass and lengths, and soil C pools (microbial biomass C and total soil C) were assessed. Results: Soil matrix treatment and maize hybrid primarily drove root exudation and belowground C inputs. Short-stature maize produced 22% greater dry root biomass than tall hybrids across N treatments. N fertilization influenced root growth and C inputs, with moderate rates generally promoting greater belowground C allocation, while excessive rates (particularly >180 kg N ha'¹ in loamy mixtures) suppressed root biomass and reduced root C inputs. Soil microbial biomass C was greater in loamy soil and peaked at intermediate N rates, with minimal effects of hybrid selection. Conclusion: This study shows that maize hybrid selection and N fertilization interact to shape root-derived C inputs and soil microbial biomass, highlighting opportunities for management practices that enhance belowground C contributions.