Effects of high- and low-phenolic pea and field bean residues at contrasting doses on soil respiration, mineral N dynamics, microbial biomass, and subsequent barley growth
Year: 2026
Type: article
Abstract: Background and aims Legume residues are important organic inputs, but their effects depend on residue chemistry and application rate. This study examined how pea ( Pisum sativum ) and field bean ( Vicia faba ) residues with contrasting phytochemical compositions influenced soil functioning and subsequent barley growth, assessing how residue quality and dose shape soil responses. Methods A sandy loam soil was amended with residues from four legume genotypes with contrasting phytochemical profiles but similar C:N ratios, applied at low (5 t ha⁻ 1 ) and high (20 t ha⁻ 1 ) rates. Unamended and mineral fertilization treatments were included for comparison. Barley was then grown in a microcosm setup for 8 weeks, and soil CO₂ efflux, microbial biomass C, inorganic N dynamics, and plant biomass were assessed. Results High-dose applications substantially increased cumulative CO₂ emissions but led to reduced microbial biomass, lower nitrate availability, and significantly suppressed barley growth, particularly for high-phenolic genotypes. In contrast, low-dose low-phenolic residues increased microbial biomass, promoted nitrification, and supported barley growth comparable with mineral fertilizers. Phenolic-rich residues maintained higher ammonium levels and showed reduced microbial and plant responses, indicating inhibitory effects of certain phytochemicals on soil processes. Conclusion Residue impacts on soil processes and crop performance depend strongly on both phytochemical composition and application rate. Low-phenolic residues applied at moderate doses have positively impacted microbial functioning, nitrogen cycling, and barley biomass, whereas high doses, especially of high-phenolic material, were detrimental to microbial activity and plant growth. Integrating residue chemistry into nutrient management could enhance the sustainability of legume-based cropping systems.
Source: Plant and Soil
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $4,790
Funders: Universidade Católica Portuguesa, Rural and Environment Science and Analytical Services Division, James Hutton Institute, Government of the United Kingdom, Department for Environment, Food and Rural Affairs, UK Government, European Commission, HORIZON EUROPE Framework Programme, Fundação para a Ciência e a Tecnologia, Horizon 2020
Awards: G1043467623, G1187831582, G254442056, Valorising and balancing the ecosystem service benefits offered by legumes, and legume-based cropped systems, G3254177986, G4160568558, ReAlising DynamIc vAlue chaiNs for underuTilised crops, Innovative concepts and technologies for ECOlogically sustainable NUTRIent management in agriculture aiming to prevent, mitigate and eliminate pollution in soils, water and air, Legumes-PLUS: Legume-Polyphenol and -Lectin non-nutritional factors and their role in determining the fUnctional diverSity of soil- and gut-microbes., G7345373016, G7679192154, G8074239113
OpenAlex ID: W7169599341