KAJIAN AKTIFITAS CACING TANAH PADA LAHAN RUANG TERBUKA HIJAU (RTH) DALAM KAMPUS UNIVERSITAS RIAU, PEKANBARU BERDASARKAN PRODUKSI KASCING

Abstract

The objectives of this study were to investigate the effect of ground cover vegetation types and precipitation on earthworm activity and to assess the earthworm contribution to soil porosity in green open spaces (“RTH”) at the campus of Riau University. Four different cover vegetation types were examined: grass, shrubs, single tree and compound trees. This study was conducted from March-May 2013. Twenty observation plots of 1 m x 1 m were randomly selected to represent each cover vegetation type. The cast productions was observed every 5 days within 50 consecutive days. Precipitation data of the same period was obtained from the Meteorological Office of Pekanbaru City. The environmental condition in each plot was characterized based on four parameters: the ground cover vegetation, root mass, soil bulk density, and soil pH. Chemical analysis was carried out to determine C-organic, total N, P, and K as well as P-available contents of soil and cast samples. Texture analysis was also performed on soil and cast samples. The results showed that cover vegetation type and precipitation significantly influenced earthworm activity (P<0.05) as indicated by the amount of cast produced. Casts had significantly higher content of C-organic, total N, P, and K as well as P-available compared to soil (P<0.05). Casts also had smaller sand fraction but higher clay fraction than soil. In conclusion, the most active earthworms, thus also enhancing soil porosity the most, were found under shrubs while the least active were found under grass as reflected in cast production level.