Diversity of the edaphic macrofauna in areas managed under no-tillage for different periods

Agriculture can considerably change the composition and richness of the edaphic macrofauna, affecting the ecological and biological functions exerted by the fauna. This study was carried out in commercial production systems in the municipality of Guaira, state of Parana, Brazil. The objective of this study was to evaluate the effect of no-tillage systems (NTS) and seasonality on the diversity, richness, and composition of the edaphic macrofauna. Three areas managed under NTS for different periods 7 years (NTS-7), 14 years (NTS-14), and 23 years (NTS-23) under crop succession with soybean (summer) (aNTS7) and maize/wheat (winter) (NTS14 and NTS23) were evaluated, in addition to a native Atlantic Forest segment, which was used as a reference. Faunal samples were collected in the thy season (September 2013) and rainy season (February 2014). The edaphic macrofauna was evaluated using the method proposed by the Tropical Soil Biology and Fertility Program. Parametric statistics were applied, and the results were compared using Tukey's test at a level of significance of 5%. Species density and total richness were usually higher in the NTS14 and NTS23 in the thy season. However, higher indexes of equability were not detected because of the dominance of groups Formicidae and Isoptera. The areas with the highest equability were the reference area in the thy season and NTS23 in the rainy season, corresponding to 0.87 and 0.61, respectively. These results indicate the higher faunal diversity in these areas, which reflects the greater stability of the ecosystem.