Kajian Jenis Cacing Tanah sebagai Bioindikator di Hutan Sekunder dan Agroforestri Kopi Desa Kutagugung Kecamatan Naman Teran Kabupaten Karo

Abstract

An experiment has been conducted to determine the types of earthworm as a bioindicator, the population of earthworm, the growth response of earthworm and its role in changing soil nutrient on either secondary forest or coffee agroforestry. The study site was settled through purposive random sampling where square plots 25 x 25 cm were located with 15 replications for each. From all plots, earthworm and soil then sampled and treated as follow: P1 = untreated controlled, P2 = Pontoscolex corethrurus, P3 = Pheretima sp. on secondary forest and K1 = untreated controlled, K2 = Pontoscolex corethrurus on coffee agroforestry. Of all species, Amynthas sp., Pheretima sp. and Pontoscolex corethrurus were present in both locations, while Peryonix sp. was only found in coffee agroforestry. The result indicated that the highest population density was found in coffee agroforestry (283,73 ind/m2). In secondary forest and coffee agroforestry, Pontoscolex corethrurus was determined as a bioindicator earthworm with relative density and occurrent frequency 60,81 %, 60 %, respectively and Pheretima sp. with relative density and occurrent frequency 36,49 %, 53 %, respectively. In coffee agroforestry Pontoscolex corethrurus also determined as a bioindicator earthworm with relative density and occurrent frequency 91,73 %, 100 %, respectively. Growth response that produced cocoon and juvenile was highest on P2. The effect of body weight on length was highest on K2. The best soil nutrient of all media was indicated on P2, P3 and K2.

Penelitian mengenai cacing tanah sebagai bioindikator, populasi cacing tanah, respon pertumbuhan cacing tanah dan peranannya dalam merubah unsur hara tanah telah dilakukan di hutan sekunder dan agroforestri kopi. Penentuan lokasi menggunakan metode purposive random sampling dengan plot kuadrat 25 x 25 cm, 15 plot pada tiap lokasi. Sampel tanah dan cacing tanah dari tiap plot diuji sebagai berikut: P1 = kontrol tanpa perlakuan, P2 = Pontoscolex corethrurus, P3 = Pheretima sp. pada hutan sekunder dan K1 = kontrol tanpa perlakuan, K2 = Pontoscolex corethrurus pada agroforestri kopi. Amynthas sp., Pheretima sp. dan Pontoscolex corethrurus ditemukan pada tiap lokasi, sedangkan Peryonix sp. hanya ditemukan di agroforestri kopi. Kepadatan populasi tertinggi terdapat di agroforestri kopi (283,73 ind/m2). Jenis cacing tanah bioindikator di hutan sekunder, yaitu Pontoscolex corethrurus dengan nilai kepadatan relatif dan frekuensi kehadiran 60,81 %, 60 %, secara berurutan dan Pheretima sp. dengan nilai kepadatan relatif dan frekuensi kehadiran 36,49 %, 53 %, secara berurutan. Pontoscolex corethrurus juga merupakan jenis cacing tanah bioindikator di agroforestri kopi dengan nilai kepadatan relatif dan frekuensi kehadiran 91,73 %, 100 %, secara berurutan. Respon pertumbuhan, produksi kokon dan juvenil tertinggi terdapat pada P2. Pengaruh berat terhadap panjang tubuh tertinggi diperoleh pada K2. Nilai unsur hara tanah terbaik pada P2, P3 dan K2.