Work

Plant secondary metabolites in beef cattle diets affect reactive nitrogen and greenhouse gas emissions during manure soil application: A laboratory incubation

Year: 2025

Type: article

Abstract: Feed additives in beef cattle diets can reduce enteric greenhouse gas (GHG) emissions. However, subsequent effects on soil carbon (C) and nitrogen (N) after land application of manure from additive-fed animals remain largely unknown. In this study, manure (mainly feces) from beef cattle fed either an un-supplemented diet (UN) or a diet containing one of two essential oil-based feed additives, Agolin® (AG; 1 g/steer/day) or Mootral® (MT; 23.5 g/steer/day), were collected and applied to soils with different textures (clay or sandy loam). The soil-feces mixtures were incubated in a completely randomized block design at two moisture levels, 50 % and 90 % water holding capacity (WHC). The AG treatment, versus MT and UN, yielded lower cumulative mineralized N (N min ; p < 0.01) in clay at 90 % WHC, but not at 50 % WHC. Similarly, AG, versus MT and UN, had lower carbon dioxide (CO 2 ) emissions in clay at 90 % WHC ( p < 0.01), but higher emissions in sandy loam at 90 % WHC ( p < 0.01). There were no differences in CO 2 among treatments at 50 % WHC. Nitrous oxide (N 2 O) emissions were only affected by soil type ( p = 0.01) regardless of soil moisture or feed additives. Methane (CH 4 ) emissions were affected by soil moisture ( p = 0.03) and the interaction soil × moisture × manure ( p < 0.01), however the feed additives had no effect. These findings indicate that the feed additives tested may affect C dynamics and N min in a soil and/or moisture-dependent manner. • Essential oil-based feed additives may remain bioactive in manure amended soils. • A coriander-based additive (AG) reduced NO 3 − and CO 2 in manure-soil mixtures. • A polyphenol-based additive (MT) had minimal effect on emissions or mineralization. • Mineralization and greenhouse gas emissions were affected by soil and moisture. • Reducing manure emissions and mineralization to mitigate environmental impact

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.179497

Authors: Matthew L. Klein, Xia Zhu-Barker, Sebastian E. Mejia Turcios, William R. Horwath, Frank M. Mitloehner

Institutions: University of California, Davis, University of Wisconsin–Madison

Language: English

Topic: Soil Carbon and Nitrogen Dynamics

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Climate action, Zero hunger, Life on land, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $4,250