engleski

Structure of nematode communities in nine types of ecosystems

Nematode communities were analyzed in nine ecosystems: winter wheat in crop rotation - standard tillage ; winter wheat in crop rotation – reduced tillage ; corn in monoculture ; sugar beat ; potato - chemical plant protection ; potato - integrated plant protection ; alfalfa ; grassland ; poplar forest. Sampling was done in 1997 and 1998, in spring and autumn, on the depth of 15-20 cm. Nematode communities were analyzed to genus level. Greatest number of nematodes and number of genera were 2843 nematodes/100 g of soil in alfalfa treatment, and 30 genera in poplar treatment. Lowest was in row crops (216 and 12 genera in sugar beat). Analyzes of nematode trophic structure showed greatest abundance of bacterial feeders and plant parasitic nematodes in all treatments, and lowest abundance of omnivorous nematodes and predators. The greatest abundance of predators was determined in poplar forest. Positive correlation between quantity of humus and total number of nematodes was determined and negative correlation between amount of K20 and number of genera. Statistically very significant differences occurred between treatments in analyzing MI, PPI and PPI/MI and showed the most disturbed nematode communities in row crops, the less disturbed in poplar forest, grassland and alfalfa ; and intermediate group was wheat with reduced and standard tillage.

nematode communities ; nine different agroecosystems

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