Penilaian Tingkat Perkembangan Tanah pada Setiap Satuan Lereng Sepanjang Katena di Penggunaan Lahan Tegalan Sub-DAS Kaliwungu, Kajoran, Magelang

CHARINA WIJAYANTI, Prof. Dr. rer. nat. Junun Sartohadi, M.Sc.; Nur Ainun H.J. Pulungan., M.Sc., PhD.

2020 | Skripsi | S1 ILMU TANAH

Penelitian perkembangan tanah sepanjang katena biasanya dilakukan pada bentangan yang panjang sehingga variasi bahan induk, tutupan vegetasi, dan iklim tidak dapat dihindarkan. Penelitian yang dilakukan di Sub-DAS Kaliwungu dilakukan pada bentangan katena yang pendek agar dapat memperoleh gambaran perkembangan tanah yang terjadi atas pengaruh tunggal perbedaan karakteristik lereng. Penelitian menggunakan metode survey lapangan dan uji laboratorium. Metode survey lapangan diawali dengan interpretasi foto udara. Wilayah penelitian mengandung unit-unit lereng yang dibagi menjadi enam bagian yaitu zona residu (sisa) I, zona erosi (pengikisan) I, zona deposisi (pengendapan) I, zona residu (sisa) II, zona erosi (pengikisan) II dan zona deposisi (pengendapan) II. Pengukuran / deskripsi tanah dilakukan pada setiap zona melalui pengamatan profil. Setiap horison di dalam profil diambil contoh tanah untuk pengujian laboratorium. Hasil pengukuran tanah di lapangan dan di laboratorium digunakan untuk penilaian perkembangan tanah di setiap profil. Tingkat perkembangan tanah dibandingkan antara profil-profil yang diamati. Hasil pengolahan disajikan dalam bentuk grafik dan tabel. Data hasil analisis digunakan untuk klasifikasi tanah yang ditentukan berdasarkan Key to Soil Taxonomy USDA 2014. Tanah diklasifikasikan hingga family tanah kemudian dilakukan padanan tanah menggunakan klasifikasi FAO 2014 dan klasifikasi Pusat Penelitian Tanah (PPT Bogor 2014). Hasil penelitian menunjukkan bahwa tanah-tanah sepanjang transek katena di Sub-DAS Kaliwungu memiliki karakteristik, perkembangan, dan klasifikasi yang berbeda. Klasifikasi tanah USDA 2014 pada lereng satu (ZR 1, ZE 1 dan ZD 1) berkembang tanah Ultic Hapludalfs, Kaolinitik Isohipertermik sedangkan lereng dua (ZR 2, ZE 2 dan ZD 2) berkembang tanah Typic Hapludalfs, Antigoritik Isohipertermik. Klasifikasi tanah berdasarkan sistem FAO 2014 semua profil tanah termasuk dalam Chromic Luvisols (Clayic), sedangkan berdasarkan PPT Bogor 2014 tanah termasuk dalam Mediteran Kromik (Mc).

Research on soil development along catena was commonly carried out on long transect so variations in parent material, vegetation cover, and climate are unavoidable. Research carried out in the Kaliwungu Sub-watershed was carried out on a short catena in order to obtain a picture of soil development that occurred under the influence of a single slope characteristic. The research applied the field survey method and laboratory test. The field survey method starts with the interpretation of aerial photographs. The study area consist slope units which are divided into six sections, namely residue zone I, erosion zone I, deposition zone I, residual zone II, erosion zone II and deposition zone II. Soil profile descriptions were carried out in each zone. Each horizon in the profile was taken from soil samples for laboratory testing. The results of soil measurements in the field and in the laboratory were used for assessment of soil development in each soil profile. Soil development rates were compared between the observed profiles. The results of processing were presented in the form of graphs and tables. Data analysis results were used for land classification determined based on the USDA Key to Soil Taxonomy version 2014. Soil was classified up to the family level and then soil also classified based on FAO soil classification systems version 2014 and Indonesian Soil Research Center classification systems (PPT Bogor 2014). The results showed that the soils in the Kaliwungu Sub-watershed have differences in characteristics, developments stage, and classifications unit. The 2014 USDA soil classification on the slope one (ZR 1, ZE 1 and ZD 1) developed Ultic Hapludalfs, Isohipertermic Caolinitics while the slope two (ZR 2, ZE 2 and ZD 2) developed Typic Hapludalfs, Isohipertermic Antigoritic soils. Soil classification based on FAO soil classification systems version 2014 all soil profiles were included in Chromic Luvisols (Clayic), while based on the Soil Research Center classification (PPT Bogor 2014) all soil profiles were included in the Mediteran Kromik (Mc).

Kata Kunci : Perkembangan Tanah, klasifikasi tanah, Sub-DAS Kaliwungu