MINERALISASI NITROGEN DI BAWAH TEGAKAN HUTAN Eucalyptus pellita DAN Acacia mangium Di SUMATERA SELATAN

LA ODE RUSTAM, Prof. Dr. Ir. Bambang Hendro Sunarminto, SU

2014 | Tesis | S2 Ilmu Tanah

Mineralisasi N merupakan perubahan bentuk dari senyawa organik ke ikatan anorganik. Nitrogen dalam bentuk anorganik sangat penting karena merupakan bentuk yang dapat diserap tanaman untuk pertumbuhan dan produksi. Perbedaan jenis tegakan hutan antara E. pellita dan A. mangium dapat mempengaruhi tingkat mineralisasi N. Penelitian ini bertujuan: mengukur mineralisasi N-anorganik (NH4 + dan NO3 -) serta membandingkan kadar amonium, nitrat dan mineralisasi N di bawah tegakan hutan E. pellita dan di bawah tegakan hutan A. mangium. Serta mempelajari proses mineralisasi di bawah tegakan hutan E. pellita dan A. mangium. Penelitian dilakukan di lapangan dan di laboratorium dari bulan Februari sampai Juli 2013. Pengamatan dan pengambilan contoh tanah dilakukan di bawah tegakan hutan A. mangium dan E. pellita di tiga lokasi yang berbeda yaitu Banding Anyar, Gemawang dan Suban Jeriji di lokasi PT. Musi Hutan Persada Sumatera Selatan. Kegiatan inkubasi dan analisis tanah dilakukan di Laboratorium Ilmu Tanah Fakultas Pertanian UGM. Penelitian menggunakan rancangan acak kelompok terdiri dari 2 perlakuan jenis tegakan hutan dan 3 ulangan sehingga dihasilkan 6 perlakuan. Hasil penelitian menunjukkan tanah dibawah tegakan jenis tanaman hutan A. mangium memiliki kadar lengas, bahan organik, kadar N tersedia, C-organik, N total lebih tinggi dan C:N ratio lebih rendah. Tanah di bawah tegakan hutan jenis tanaman E. pellita memiliki pH dan partikel lempung lebih tinggi. Kadar ammonium, nitrat dan mineralisasi N tertinggi terdapat di bawah tegakan hutan A. mangium dan kadar ammonium, nitrat dan mineralisasi N terendah terdapat di bawah tegakan hutan E. pellita. Mineralisasi N di lokasi penelitian baik di bawah tegakan E. pellita maupun di bawah tegakan hutan A. mangium termasuk dalam proses nitrifikasi.

N mineralization is a change in the form of organic compounds to inorganic bonding. The organic form of nitrogen is very important because it is a form that can be absorbed by plants for their growth and production. The different types of forest stands between E. pellita and A. mangium can affect N mineralization rate. The aim of this study: to measure inorganic mineralization (NH4 + and NO3 -) and compared the levels of ammonium, nitrate and N mineralization under forest stands of E. pellita and A. mangium. And also to study the mineralization process under forest stands of E. pellita and A. mangium. The research was conducted in the field and in the laboratory from February to July 2013. The observation and soil sampling was conducted under forest stands A. mangium and E. pellita in the three different locations namely Banding Anyar, Gemawang and Suban Jeriji at the location PT. Musi Hutan Persada, South Sumatra. Incubation activities and soil analysis carried out at the Laboratory of Soil Science, Agriculture Faculty, Gadjah Mada University. The research uses complete randomized block design consisting of two treatment types of forest stands and 3 replications so that it result 6 treatment. The result shows that the soil under the stand of A. mangium has higher soil moisture content, organic matter, N content, available N content, organic C and N total, while the C/N ratio is lower. The soil under the stand E. pellita has higher pH and clay particle. The hisghest level of ammonium, nitrate and N mineralization are under the stand of A. mangium compared under stand forest of E. pellita. The mineralization in the research location either under the stand of E. pellita or A. mangium is included in nitrification process.

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