2025/08/20 by Lena Wöhl, Björn Kemmann, Thorsten Ruf +3 · 1 voice
Agricultural and Biological Sciences · Engineering · #Soil Carbon and Nitrogen Dynamics #Bioenergy crop production and management #Forest Biomass Utilization and Management
paper · pdf · doi:10.1007/s11104-025-07696-w
openalex publication_date 2025/08/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Abstract Aims Cup plant ( Silphium perfoliatum ) contributes to sustainable bioenergy production. However, little is known about the role of intensive litter fall and increased soil biodiversity on respiration and denitrification in its cultivation. This study aimed to assess CO 2 , N 2 O and N 2 emissions of annual and perennial energy cropping systems affected by earthworms when supplied with senescent cup plant or maize litter. Methods In a 32-day laboratory incubation, the 15 N gas flux method was applied in an N 2 -reduced atmosphere to a repacked silt loam soil, inoculated with Lumbricus terrestris L., and amended with senescent maize and cup plant litter. During incubation, CO 2 , N 2 O and N 2 emissions were measured. After incubation, NO 3 − , NH 4 + , total C, and total N was analysed in soil and casts. Litter removal from the soil surface and net nitrification rates were calculated. Results Earthworms caused a fivefold increase in maize litter removal and a threefold increase regarding cup plant litter. Highest N 2 O + N 2 fluxes were observed in treatments with earthworms and cup plant litter, although the high CN ratio of senescent cup plant litter implied higher N immobilisation than the CN ratio of senescent maize litter. Earthworms increased CO 2 , N 2 O, and especially N 2 emissions lowering the product ratio of denitrification ( N 2 Oi ). Conclusions Earthworm-controlled litter incorporation increased labile C from decomposition of recalcitrant litter as substrate for denitrification. Mineralisation patterns of senescent litter cannot be explained by CN ratio alone. The combination of both mechanisms affected denitrification, lead to elevated N 2 O and N 2 emissions and N loss from the soil.