MINERALIZATION/IMMOBILIZATION OF NITROGEN AND PHOSPHOROUS IN COMPOSTED GROWING MEDIA

M. Contin, M. De Nobili, C. Cattivello
The effects of different temperature and moisture regimes of a composted growing medium on N and P plant-availability and main differences with a peat-based growing medium have been evaluated during laboratory incubation experiments. The influence of root growth has also been tested by plant growth experiments. Microbial biomass and extractable N and P have been determined during a time-course incubation up to 56 days. The microbial biomass carbon (Bc) was relatively high in the composted growing media (2900–3600 µg Bc g-1) but less influenced by treatments. In contrast, Bc was much lower in peat-based growing media (350–600 µg Bc g-1) but more modified by the incubation conditions, especially by drying/rewetting cycles and by root growth. On the other hand, mineral N and extractable P were much less affected in the peat-based growing media than in the composted growing media. The cyclic changes of moisture regimes in particular, produced a much higher mineralization rate. In the composted growing media, small changes in soil microbial biomass were associated with larger changes in microbial activity.
Contin, M., De Nobili, M. and Cattivello, C. (2008). MINERALIZATION/IMMOBILIZATION OF NITROGEN AND PHOSPHOROUS IN COMPOSTED GROWING MEDIA. Acta Hortic. 779, 599-606
DOI: 10.17660/ActaHortic.2008.779.77
https://doi.org/10.17660/ActaHortic.2008.779.77
substrates, compost, nutrients availability, microbial biomass, temperature, moisture
English

Acta Horticulturae