The influence of no-till (NT) and conventional tillage (CT) systems, native forest (NF) and grassland (G), on the population density and biomass of Oligochaeta Amynthas spp., at Campos Gerais in the state of Paraná, Brazil, was evaluated monthly between February 1993 and January 1994. For the NT and CT systems, the areas were cultivated with corn, triticale and soybean, while, the native field consisted of vegetation of steppes of low grasses and a range forest of gallery forest. The population density was determined by the 0.22% formalin method and biomass was measured by weighing. The population density and biomass were greater in the NT and FN, compared with CT, while, in G, Amynthas spp. did not occur. The most expressive values population density and biomass in the ecosystems NT and NF were observed in the summer and spring.
no-till; conventional tillage; native forest; native grassland; Amynthas spp; earthworms