Effect of ensilaged vegetable crop residue amendments on soil carbon and nitrogen dynamics

• Ensilage of vegetable residues may reduce N losses in intensive vegetable rotations.
• Reapplication in spring may aid in synchronizing nutrient demand and availability.
• Ensilaged vegetable residues stimulated soil microbial activity after incorporation.
• Optimal timing between crop planting and ensilage application should be evaluated.

Vegetable crop residues aid in maintaining soil quality and fertility, but pose a high risk of N-losses during autumn. Removal and conservation of these residues followed by a timely reapplication in spring may aid in synchronizing nutrient demand and availability. Crop residues of four vegetables were co-ensilaged with maize straw in a 1:1 ratio on volume base. Silage of leek and white cabbage were incubated with soil for measuring C and N mineralization and N fertilizer replacement value (NFRV). Vegetable crop residue silage promoted microbial activity when reapplied to the soil. This led to a temporary N immobilization up to 30% of the applied N after 14 days. A limited remineralization of up to +4% took place after 115 days which was confirmed by the positive NFVR. Nitrogen (N) losses during co-ensilage of vegetable crop residues were small and may help reduce N losses in intensive vegetable crop rotations during winter.