Penilaian Perkembangan Tanah di Lereng Gunungapi Ijen Berdasarkan Pendekatan Pedogeomorfologi

PUNCAK JOYONTONO, Prof. Dr. Junun Sartohadi, M.Sc.

2016 | Skripsi | S1 GEOGRAFI DAN ILMU LINGKUNGAN

Penelitian ini bermaksud untuk mengkaji perkembangan tanah pada material gunungapi yang pada umumnya merupakan material mudah lapuk dan cepat membentuk tanah. Tujuan penelitian adalah (1) mengidentifikasi karakteristik morfologi tanah, (2) mengidentifikasi karakteristik fisik tanah, (3) mengidentifikasi karakteristik kimia tanah, dan (4) menilai tingkat perkembangan tanah di sekuen lereng Gunungapi Ijen. Penelitian dilakukan berdasarkan pendekatan pedogeomorfologi. Terdapat 7 titik pengamatan profil tanah di sepanjang lereng Gunungapi Ijen. Deskripsi morfologi tanah dilakukan di lapangan pada setiap titik pengamatan profil. Pengambilan contoh untuk uji laboratorium dilakukan pada setiap horison tanah. Uji laboratorium mencakup pengukuran tekstur tanah dan kadar organik tanah. Genesis tanah dinilai secara deskriptif berdasarkan pada urutan perlapisan material vulkanik yang menjadi bahan induk tanah. Perkembangan tanah dinilai secara deskriptif berdasarkan morfologi tanah dan karakteristik tekstur dan kadar bahan organik. Hasil penelitian menunjukan bahwa semua satuan tanah yang ada berasal dari abu gunungapi dan perkembangan tanahnya masih tergolong muda. Profil-profil tanah tersusun atas horison tanah A-C yang berulang. Tanah yang berkembang masih mencerminkan karakteristik bahan induk tanahnya. Karakteristik fisik pada horison A di semua satuan tanah bertekstur geluh pasiran, berstruktur lemah, dan berwarna gelap (10 YR 3/4). Kandungan lempung dan bahan organik menurun seiring penurunan kedalaman tanah, namun kadar keduanya meningkat pada horison Ab (tanah terkubur).

The goal of the research was to carry an assessment of soil development on volcanic materials that generally understood as easy weathered materials to perform soils. The more detail objectives were: (1) to identify soil morphology characteristics, (2) to identify soil physical characteristics, (3) to identify soil chemical characteristics, and (4) to assess the soil development at Ijen Volcanic slope. The research was based on pedogeomorphological approach. There were 7 location of soil profile in Ijen Volcanic slope. Characteristic of soil morphology described in the field at every single soil horizon. Laboratorium tests covered to measure clay degree and organic metters degree at every soil horizon. Assessment of soil genesis descriptively based on volcanic materials stratigraphy that were be soil parent materials. Assesment of soil development descriptively based on soil morphology, soil texture, and organic materials in soil profiles. Result of the research showed that in soils were developed from volcanic ash. Soils in all location included light development. Soil profiles were arranged by A-C horizons that recur. Developing soils had characterstic that were like it�s parent materials. Physical charactersitic of A horizons had sandy loam texture, light structure, and dark colour (10 YR 3/4). Clay and organic metters degree decreased while go down to the depth, but increased at Ab horizons (buried soils).

Kata Kunci : pendekatan pedogeomorfologi, karakteristik tanah, perkembangan tanah, sekuen lereng Gunungapi Ijen/pedogeomorphological approach, soil characteristic, soil development, Ijen Volcanic slope.