C- und N-Verbindungen aus Bioabfallkomposten und ihre Bedeutung für die N-Nachlieferung

Abstract

An application of 30 t dry matter/ha of biowaste compost contains nearly 6.6 t carbon and 1.7 t as cellulose C in addition to 2.6 t in the form of lignin C. Our field and incubation experiments indicate that in addition to the N_t concentration and the C_t/N_t ratio of the biowaste compost, the CaC1₂ extractable C_org/N_org and the lignin/N_t ratio are of great importance for the long term N mineralization. The short-term N mineralization was strongly influenced by the cellulose concentration of the biowaste compost. Application of lignin reduced the N mineralization caused by N immobilization. This potential of N immobilization in soil with repeated biowaste compost application was lower as that of the soil with mineral N fertilization. These results show that a repeated biowaste compost fertilization has a quantitative and qualitative influence on the N mineralization potential of soils.