SOIL MICROARTHROPOD COMMUNITY STRUCTURE OF CORN PRODUCTION SYSTEMS IN TABANGO, LEYTE, PHILIPPINES

摘要

The soil microarthropod communities in different corn production systems were studied and compared in four farms in Barangay Omaganhan, Tabango, Leyte from April to August 2003. The aspects considered were relative abundance, species richness, species similarity, species diversity, species evenness, and species dominance. They were represented by 193 species, largely Acarina (> 90%) and Collembola (8.4%).The most dominant mites in all farms were Scheloribates fimbriatus javensis Willmann, Oppia kuehnelti Csiszar, and Lamellobates hauseri Mahunka.The relatively poor community structure of mites and Collembola in the corn farms was influenced by the low organic matter (1.2-1.9%) and total N (0.12-0.16%) levels and slightly basic pH (7.75-7.95) of soil. While high rainfall during typhoons caused drastic decline in mite populations, it did not appear to affect Collembola populations. The influence of soil moisture on microarthropods was not apparent. Frequent cultivation, use of chemical fertilizer, use of contour hedgerows, crop rotation, and intercropping appeared to influence microarthropod community trends.Corn farms in Tabango, Leyte were assessed as highly disturbed, but showed prospects for rehabilitation through soil improvement schemes. Recommendations for the improvement of existing farming practices, information dissemination of improved technologies, and future studies relevant to corn production in Leyte are provided.