Table 1_Integrating winter legume cover crops in temperate rice cropping systems for enhancing carbon and nitrogen inputs without increasing GHG emissions.docx

In northern Italy, cultivating a winter leguminous cover crop (CC) in conventional monocropped rice systems may represent an important source of organic matter (OM) to sustain soil fertility and nitrogen (N) for crop nutrition. However, incorporating fresh green manure before flooding may also stimulate methane (CH₄) production by increasing the availability of labile OM under anaerobic conditions.

This study evaluated the agronomic and environmental implications of introducing Vicia villosa Roth as a winter CC in a rice-based system managed under dry seeding followed by continuous flooding. Plots with CC were compared to a winter fallow over two consecutive growing seasons, during which biomass inputs, porewater chemical composition, GHG fluxes, and soil organic matter (SOM) composition were evaluated. Hairy vetch established successfully in both years and provided inputs of 1.91 ± 0.32 and 2.72 ± 0.19 t C ha^-1 and 180 ± 30 and 240 ± 30 kg N ha^-1.