Thesis

Keragaman dan populasi cacing tanah pada lahan dengan berbagai masukan bahan organik di daerah Lampung Utara

Abstract

A study of eathworm diversity and population density has been done in* North Lampung. The population and the species were investigated from three types of hedgerows; with different resources of organic matter. 'Me organic matter resources were from gamal (Gliricidia sepium/high quality), saga (Peltophorum dasyrrachis low quality) and mixture of G. sepium and P. dasyrrachis. A plot without organic input except from crop residue was used as control. The results of all plots were compared to secondary forest. Samples were collected from soils at 015 and 15-30 cm depth and respectively 0.5, 1.0 and 1.5 m from hedgerows. The samples were collected in dry and wet season. The results showed that earthworm diversity decreased from seven species in secondary forest to six in hedgerow intercropping and five in control. The high population were found in hedgerow intercropping with P. dasyrrachis and mixed hedgerows about 50 and 42 m- respectively. At 0-15 cm soil depth the population was higher than it is found at 15-30 cm depth (89.33% m'2). Distances from hedgerow plants did not influenced significantly the population, biomass and number of cocoons. Compared to the results (if control and secondary forest, the seasons have influenced significantly. High population was found in the dry season about 40 m-2 In the hedgerow intercropping the high biomass was found in A dasyrrachis and 2 mixed as input organic matter resources on 0-15 soil depth i.e. 9.91 and 8.56 g m. respectively. The results were not significantly different from both the control and secondary forest. The high number of cocoon was found in secondary forest and in P. dasyrrachis plot about 54 and 32 m-2 respectively. It was found about two to three times more worm casting activity on 0,5 m than 1,0 and 1,5 m from hedgerows and five times under forest cover than hedgerows. All of the results showed that low quality organic matter input was more favorable for earthworm