Soil nematodes in cambisol agroecosystems of the Czech Republic

Soil nematodes were studied in 16 conventional agroecosystems of five crops (wheat, barley, oats, potatoes, and clovers) in S, SW and NW Bohemia. About 60 genera and 160 species of soil nematodes were identified and the majority of dominant species belonged to the orders Rhabditida and Tylenchida. Most nematode individuals were bacterivores (48%) and plant parasites (24%). The total mean nematode abundance varied from about 0.5 to 2.1 X 10(6) ind. m(-2), the total biomass from 0.2 to 1.1 g m(-2), and the mean biomass of a nematode individual in community from 0.22 to 0.63 mug live weight. Region and cultivated plant were the main factors influencing taxonomic composition of nematode communities. Matrix classification of nematode functional guilds revealed food webs in the majority of agroecosystems as 'disturbed' to 'degraded'. Decomposition channels in the field soils, as indicated by nematodes, varied from fungal through fungal-bacterial to bacterial pathways and seemed to be influenced by both regional and crop factors.