Karakteristik Inceptisol pada toposekuen lereng selatan Gunung Merapi Kabupaten Sleman
MALIDI, Laode, Dr.Ir. Bambang Hendro S., SU
2005 | Tesis | S2 Ilmu TanahPenelitian toposekuen perkembangan tanah Inceptisol di Kecamatan Pakem, Kabupaten Sleman bertujuan untuk mempelajari perubahan karakteristik Inceptisol ditinjau dari perbedaan topografi. Pada tanah yang terletak pada kelas topografi yang berbeda dilakukan penyidikan sebanyak tiga profil pewakil yaitu: Gunungsari (tinggi tempat 532 mdpl, kelas topografi bergelombang, dengan kelerengan 20-23%), Ketulan (tinggi tempat 386 mdpl, kelas topografi berombak, dengan kelerengan 11-13%) dan Tegal Ngasem (tinggi tempat 320 mdpl, kelas topografi landai, dengan kelerengan 3-6%). Parameter tanah yang dianalisis terdiri atas: sifat morfologi, fisika, mineralogi dan kimia. Hasil penelitian dari ketiga profil pewakil dari profil tertinggi (Gunungsari) sampai profil terendah (Tegal Ngasem) menunjukkan: nilai BJ: Gunungsari berkisar 2,7-2,9 g/cm3, Ketulan berkisar 2,66-2,67 g/cm3, Tegal Ngasem berkisar 2,55-2,62 g/cm3. Nilai BV: Gunungsari berkisar 1,37-1,65 g/cm3, Ketulan berkisar 1,51-1,52 g/cm3, Tegal Ngasem berkisar 1,46-1,5 g/cm3. Nilai pH H2O: Gunungsari berkisar 6,25-6,42, Ketulan berkisar 6,21-6,23, Tegal Ngasem berkisar 6,20-6,62; Nilai pH KCl: Gunungsari berkisar 5,91-6,09, Ketulan berkisar 5,43-5,47, Tegal Ngasem berkisar 5,43-5,83. Nilai bahan organik: Gunungsari berkisar 0,94-3,19%, Ketulan berkisar 1,52-1,53%, Tegal Ngasem berkisar 1,10-1,83%. Nilai KPK: Gunungsari berkisar 6,30-6,61 cmol(+)/kg), Ketulan berkisar 5,97-6,31 cmol(+)/kg, Tegal Ngasem berkisar 5,54-7,90 cmol(+)/kg). Nilai kation-kation basa tertukar (Ca2+, Mg2+, K+, Na+): Gunungsari berkisar 0,04-0,67 cmol(+)/kg, Ketulan berkisar 0,08-0,42 cmol (+)/kg, Tegal Ngasem berkisar 0,01-0,84 cmol(+)/kg. Nilai kejenuhan basa: Gunungsari berkisar 11-22%, Ketulan berkisar 9-22%, Tegal Ngasem berkisar 21-24%; Nilai nisbah C/N: Gunungsari berkisar 5/1-23/1, Ketulan berkisar 6/1-10/1, Tegal Ngasem berkisar 6/1-7/1. Jenis mineral Gunungsari, Ketulan dan Tegal Ngasem adalah lempung haloisit yang jumlah dan kristalisasinya makin meningkat dengan posisi profil makin ke bawah. Klasifikasi tanah profil Gunungsari, Ketulan dan Tegal Ngasem adalah Humic Psammentic dystrudepts
The toposequent research of Inceptisol development in Pakem subdistrict, Sleman district was purposed to study the changes of Inceptisol characteristic based on topographical differences. Soil that located on different topographical classes has been studied with three representative profiles, that are : Gunungsari (wavy, with slope of 20-30%), Ketulan (undulating, with slope of 11-13%) and Tegal Ngasem (slightly flat, with slope of 3-6%). The parameter of the soil analysis consisted of the characteristics of morphology, physics, mineralogy, and chemistry. The result of study with three representative profiles from Gunungsari (highest profile) to Tegal Ngasem (lowest profile) showed that the value of particle density: Gunungsari is around 2,77 g/cm3, Ketulan is around 2,67 g/cm3, Tegal Ngasem is around 2,60 g/cm3. The value of bulk density: Gunungsari is around 1,51 g/cm3, Ketulan is around 1,50 g/cm3, Tegal Ngasem is around 1,48 g/cm3. The value of pH H2O: Gunungsari is around 6,32, Ketulan is around 6,22, Tegal Ngasem is around 6,58. The value of organic material: Gunungsari is around 1,78%, Ketulan is around 1,52%, Tegal Ngasem is around 1,50%. The value of CEC: Gunungsari is around 4,56 (cmol(+)/kg; Ketulan is around 6,14 (cmol(+)/kg, Tegal Ngasem is around 6,80 (cmol(+)/kg. The value of exchange able cations (Ca2+, Mg2+, K+,N+): Gunungsari is around 0,18 (cmol(+)/kg, Ketulan is around 0,24 (cmol(+)/kg, Tegal Ngasem is around 0,37 (cmol(+)/kg. The value of base saturation: Gunungsari is around 16,3%, Ketulan is around 15,5%, Tegal Ngasem is around 22,5%; The value of C/N relative: Gunungsari is around 11, Ketulan is around 5, Tegal Ngasem is around 6. The type of clay mineral at Gunungsari, Ketulan and Tegal Ngasem are halloysites which is good crystallinity and high content with decreasing of altitude. The classification of soil is Humic Psammentic Dystrudepts for three profiles
Kata Kunci : Tanah Inceptisol,Toposekuen Lereng Gunung Merapi,Karakteristik, toposequent, soil development, Inceptisol
