Peran Mesofauna dan Makrofauna Tanah dalam Dekomposisi Bahan Organik Tanaman di Bawah Tegakan Sengon (Paraserianthes falcataria)

The purposes of the research were to know the influences of crop organic matters to diversity of soil mesofauna and macrofauna under paraserianthes’stand (Paraserianthes falcataria), rate of organic matters decomposition, as well as the relationship between the rate of organic matters decomposition and diversity of soil mesofauna and macrofauna. The framework of thinking of this research was the crop organic matters which were given to the soil would influence the soil mesofauna and macrofauna diversities. The presence of soil fauna would help the decomposition process of organic matters which fertilize the soil. This research was established under paraseanthes’stand, with 7 treatments of crop organic matters, i.e. cardamom, pineapple, cocoyam, cardamom-pineapple, cardamomcocoyam, pineapple-cocoyam, cardamom-pineapple-cocoyam, and the treatment without crop organic matters (control). The sampling of mesofauna data used soil extraction “Barlessse-Tullgreen” method, meanwhile the macrofauna data were obtained from “Hand- Sorting” method and “pit-fall trap” method. The data which have been obtained were analyzed by using Analysis of Variance (ANOVA) and continued with DMRT test. The Correlation test was done to find out the relationship between the rate of decomposition of crop organic matters and the soil mesofauna and macrofauna diversities. It can be concluded that the applying of crop organic matters influenced the soil mesofauna and macrofauna diversities. The highest coefficient value index of soil mesofauna diversity was 1.36 by using cardamom-cocoyam organic matters. The highest coefficient value index of the soil macrofauna diversity was 1.11 by using pineapple organic matters. The highest coefficient value index of macrofauna diversity on the surface of the soil was 1.27 by using pineapple organic matters. The crop organic matters of cardamom-cocoyam has the highest coefficient value decomposition rate, was 0.45. The crop organic matters of pineapple has the lowest coefficient value decomposition rate, was 0.15. The relation between the decomposition rate of crop organic matters and the soil mesofauna diversity index, the macro fauna in the soil, and macrofauna on the surface of the soil show the negative correlation, with the correlation coefficient value, were -0.01; -0.30; -0.001. Key words: decomposition, crop organic matter, soil mesofauna, soil macrofauna.