Soil macrofauna under two grazing systems

The soil macrofauna of an 18 ha Cynodon nlemfuensis award was studied for three years to compare an intensive rotational grazing system with 72 paddocks (Voisin's rational grazing), an intensive grazing system of 260 large cattle units (equivalent to 500 kg LW) and a rotational grazing with 12 paddocks and an intensity of 51 LC. Three paddocks were selected from each system in which three areas of 0.065 m(2) each were sampled at 0-20 depth once each trimesler to determine the number of macrofauna individuals, the biomass and soil humidity. Data were statistically analysed through a linear i model and also the main component method was used to analyse the influence of climatic factors on the variable studied and their relationship. There were no significant differences between the two grazing. systems in the number of individuals (4.37/m(2)) as well as their biomass (19.9 g/m(2)). Results showed differences (P< 0.01) between trimesters with the highest values in September-October-November and March-April-May. Annual performance of the macrofauna showed that in the first year there was a greater number of individuals (8.86 vs 2.26 and 1.96) as well as its biomass (39.3 vs 2.43 and 11.07 g/m(2) compared to the Following years. Among the diversity of individuals there were: earthworms, coleopterous larvae and other insects. It was determined that the first two groups had highest weights in the total biomass. Results indicate that under similar soil and climatic conditions as well as the grazing system used in this study, there will be no increases in the diversity and the biomass of the macrofauna at a short term. Further long-term studies are required.