Biodiversity of nematofauna associated with the rice field agro-ecosystem in north Italy

This research is intended to give an idea on the soil biodiversity associated with the rice field agro-ecosystem. The research was carried out in two areas of North Italy where Oryza sativa is a traditional crop. The nematodes were extracted from soil samples and from the rhizosphere of rice plants. The nematode community was investigated for the genus composition, trophic structure and biodiversity. 22 families and 45 different genera were recorded. The dominant trophic group was the bacteriophagous with the genus Rhabditis. Other important genera were Pratylenchus, Helicotylenchus and Acrobeloides. Phytophagous represent in almost all fields not more than the 20% of the total nematodes. In all the examined samples the biodiversity was quite low. The ecological indices indicate a great disturbance and a rather high level of organic matter. The data indicate a rather high level of disturbance. However these results and this functional approach through the nematofauna analysis can give an idea of the degree of biodiversity. Future studies on this subject could help to preserve or even to enhance the biodiversity and the quality of the soil.