Productivity and silage quality of forage from intercropped silage maize and perennial legumes

Intercropping provides options for on-farm production of high-quality silage. Here, alfalfa, white clover and red clover were grown with maize in 50 %/50 %, strip intercrops fertilized at 100 or 250 kg N ha⁻¹ during 2021–2023. Fresh materials from the final harvests of intercrops and sole crops were ensiled as well as their mixtures at two ratios (80 %/20 %; 60 %/40 % maize/perennial legume), with an average dry matter content of 350 g kg FM⁻¹. Dry matter, crude protein, starch, acid detergent fibre, and neutral detergent fibre concentrations were assessed using wet chemical analyses. Silage from mixtures attained higher concentrations for crude protein and starch and lower concentrations for acid detergent fibre and neutral detergent fibre (g kg DM⁻¹) than mixing silages of sole maize and sole legume. However, the dry matter yield of silage (Mg ha⁻¹) produced from maize-perennial legume intercropping was lower, albeit of higher silage quality than sole maize silage. The land equivalent ratio was 1.20 ± 0.04 for maize-white clover in 2023. Silage productivity and quality were better at high than at low N input. We found quality advantages of ensiling maize-perennial legume mixtures. However, either a 20 % or 40 % perennial legume mixing proportion in the mixed silage with maize is hard to attain through maize-perennial legume intercropping as legumes produced little at their final cuts, due to shading. Nevertheless, maize-red clover mixed silage increased quality, likely through quality changes in maize biomass. Intercropping did not allow to reduce N input while maintaining silage dry matter yield and quality.