Aplikasi Soil Taxonomy untuk tanah-tanah di Daerah Karst Gunung Kidul

WIYONO, Dr.Ir. Syamsul Arifin Siradz, M.Sc

2006 | Tesis | S2 Ilmu Tanah

Penelitian dilakukan pada bentang lahan Polygonal, Labyrinth, dan Residual di daerah karst Gunung Kidul dengan ketinggian tempat 244 meter sampai 377 meter di atas permukaan laut. Tujuan penelitian adalah mempelajari sifat fisik, kimia, dan mineralogi tanah, mengklasifikasikan tanah serta mempelajari kendala dalam aplikasi Soil Taxonomy untuk tanah-tanah yang berkembang di daerah tersebut. Metode penelitian dilakukan dengan survey lokasi dengan dasar peta topografi dan geologi, penentuan letak sample profil tanah dari tiap tipe bentang lahan, pengambilan sample profil, dan analisis laboratorium. Analisis tanah dilakukan di laboratorium Ilmu Tanah Universitas Gajah Mada, laboratorium Teknik Geologi, dan Sekolah Menengah Kejuruan Pembangunan Yogyakarta. Hasil penelitian menunjukkan bahwa sifat fisik, kimia, dan mineralogi tanah hampir sama. Tekstur tanah lempung debuan, struktur lapisan atas remah dengan konsistensi gembur, dan semakin ke bawah berstruktur gumpal dengan konsistensi teguh. Solum tipis pada puncak dan semakin tebal pada lembah. Reaksi tanah netral sampai agak alkalis, kapasitas pertukaran kation dan kejenuhan basa tinggi sampai sangat tinggi. Mineralogi bahan induk tanah hampir sama berupa bahan Vulcanic Arenite. Klasifikasi tanah berdasarkan Soil Taxonomy USDA sampai tingkat subgroup diperoleh 5 jenis tanah, yaitu Lithic Udorthents, Typic Eutrudepts, Oxyaquepts Eutrudepts, Typic Hapludalfs, dan Aquertic Chromic Hapludalfs. Kendala dalam aplikasi Soil taxonomy adalah kriteria epipedon Ochric belum spesifik, terdapat nama subordo ( Orthents ) dan great group ( Hapludalf ) tidak berdasarkan sifat tanah, serta data regim kelembaban dan temperatur tanah diperoleh melalui pendekatan data iklim karena pengukuran membutuhkan waktu lama. Implikasi penggunaan Soil Taxonomy USDA mempunyai manfaat yang lebih luas dalam pengelolaan tanah dari pada sistem FAO-UNESCO, dan PPT.

Research was conducted at unfolding farm Polygonal, Labyrinth, and Residual karst of Mount Kidul with the place height 244 metre until 377 metre above sea level. The objectives of this research are to find out the nature of physical, chemical, and mineralogy, classifying land and also study the constraint in application of Soil Taxonomy for the land of expanding in the area. Research method was conducted by survey location of under map of topography and geology, determination of situation of sample of land; ground profile of each type unfold the farm, intake of sample profile, and analyse the laboratory. Soil Analyses was conducted at soil science and geology technique laboratory of Gadjah Mada University, and SMK PembangunanYogyakarta. Result of research indicate that the nature of physical, chemical, and mineralogy of much the same to. Tekstur of Land;Ground of silty clay, structure of crumb with the consistency freable, and progressively downwards have structure blocky with the unshakeable consistency. Flimsy solum at top and thick progressively at dale. Reaction of neutral land;ground until rather alkalis, cation exchange capasity and base saturation high until very high, mineralogy of materials of land;ground mains of much the same to in the form of materials of Vulcanic Arenite. Soil Classification of pursuant to Soil Taxonomy USDA mount the subgroup obtained 5 land;ground type, that is Lithic Udorthents, Typic Eutrudepts, Oxyaquepts Eutrudepts, Typic Hapludalfs, and Aquertic Chromic Hapludalfs. Constraint in application of Soil taxonomy USDA is criterion of epipedon Ochric not yet specific, there are name subordo ( Orthents ) and great group ( Hapludalf ) do not pursuant to nature of land;ground, and also data of regim of dampness and land;ground temperature obtained to through the approach of climate data because measurement require the old time. Implication of usage of Soil Taxonomy USDA have the broader benefit in land;ground management from system FAO-UNESCO, and PPT

Kata Kunci : Lahan Karst,Soil Taxonomy, Soil Taxonomy, Unfold The Farm Karst, Mount Kidul