Biomass and diversity of the soil macrofauna in different grasslands

The biomass and the diversity of the soil macrofauna was studied during three years in ten grasslands. The data were processed using a general linear model. The types of grassland varied from natural grasslands with or without leucaena on humic calcimorphic soil in a system for fattening cattle to grasslands of improved grasses with or without trees on a red ferralic soil in a system for dairy cattle. The number of individuals of the macrofauna was very variable in each system and between years and also showed interaction. In the grasslands 1, 2 and 3 that were established on humic soil in beef production systems, the highest number of individuals (between 6 and 14 individuals/m(2)) was found and showed the most stable performance during the three years. The,grasslands 4 and 5, established in dairy systems on a brown soil, had, in general, a performance poorer than the rest, except the grassland 9 (star grass without shade on a red ferralic soil). This grassland had a lower number of individuals (3.57 and 3.70 individuals/m(2) in the first and third years, respectively). The grasslands 6, 7, 8 and 10, on a red ferralic soil, showed a similar performance (with values between 4 and 8 individuals/m(2)) and the latter was the most stable during the last three years. The biomass was superior in those established on humic calcimorphic and brown calcic soil (1, 2, 3, 4 and 5) with values higher than 30 g/m(2). The lowest biomass was found in the grasslands on red ferralic soil (6, 7, 8, 9 and 10). The macrofauna in all the grasslands was very similar and was composed of three phyla, five classes and seven orders. The classification of worms indicated the presence of two genera in all the grasslands. In the third system, the genus Diplotrema was also found. It is concluded that the macrofauna performance varied between the systems studied and biomass was superior in those developed on humic calciporphic and brown calcic soil. The third grassland had the best performance, with higher diversity of worms. The systems with trees maintained more stability in the performance of the macrofauna during the experiment.