Studi sifat-sifat fisik dan kimia tanah pada tanah timbunan lahan bekas penambangan batubara di PT. Tambang Batubara Bukit Asam (Persero) Tbk. Tanjung Enim, SUmatera Selatan

ERNAWATI, Rika, Drs. Tukidal Yunianto, M.Sc

2005 | Tesis | S2 Ilmu Lingkungan

Aktivitas penambangan batubara apabila tidak diiringi dengan upaya reklamasi maka akan terjadi degradasi lingkungan di antaranya adalah perubahan kualitas tanah, baik secara fisik maupun kimia. Reklamasi dilakukan dengan cara penanaman vegetasi pada tanah timbunan bekas penambangan batubara. Penelitian ini bertujuan untuk mempelajari sifat-sifat fisik dan kimia tanah pada tanah timbunan lahan bekas penambangan batubara. Metode penelitian ini adalah survei dan analisa laboratorium. Pengambilan sampel tanah menggunakan metode Purposive Sampling yang didasarkan pada umur timbunan tanah. Sampel tanah berjumlah 26 sampel diambil dalam kondisi tidak terganggu (undisturbed), kecuali analisis tekstur tanah, menggunakan mold dengan panjang 40 cm. Sifat-sifat fisik tanah yang diuji adalah tekstur tanah, kadar air dalam tanah, bobot isi tanah, porositas dan permeabilitas tanah. Sifatsifat kimia tanah adalah kapasitas tukar kation (KTK), bahan organik (BO), kejenuhan basa (KB), posfor tersedia, nitrogen dan kalium. Hasil penelitian didapatkan bahwa tekstur tanah umumnya liat. Kadar air bernilai antara 15,17-39,56%. Bobot isi tanah Pit 3 Barat dan Pit 1 Utara (bench 4) termasuk kelas baik (1,20-1,29g/cm3), sedangkan Pit 3 Timur dan Pit 1 Utara (bench 1) termasuk kelas buruk (1,46-1,72g/cm3). Porositas tanah Pit 3 Timur rendah hingga sangat rendah (34,41%-48%), Pit 3 Barat dan Pit 1 Utara (bench 4) termasuk kelas sedang (50,14%-53%). Permeabilitas tanah termasuk kelas tinggi (0,0036-0,0079cm/det). Hasil analisis menunjukkan bahwa semakin tua umur timbunan tanah, bobot isi, porositas dan permeabilitas tanah semakin baik, sedangkan kadar air dalam tanah tidak terlalu menjadi masalah karena curah hujan rata-rata daerah penelitian tinggi yaitu 3.040 mm. KTK daerah penelitian termasuk kelas rendah sampai tinggi (10,98- 38,57me/100g). KB Pit 3 Timur termasuk kelas sangat tinggi (97,44-99,80%), sedangkan Pit 3 Barat dan Pit 1 Utara sangat rendah (8,15-20,16%). BO termasuk kelas sangat rendah sampai rendah (0,57-3,45%). Posfor tersedia termasuk kelas sedang sampai sangat tinggi (20,31-43,67ppm). Nitrogen termasuk kelas sangat rendah hingga rendah (0,01-0,12%). Kalium tersedia umumnya sangat tinggi (66,16-169,12ppm). Hasil analisis menunjukkan bahwa tingkat kesuburan berdasarkan sifat-sifat kimia tanah yakni KTK, KB, BO dan Posfor tersedia daerah penelitian mempunyai status kesuburan sangat rendah hingga sangat tinggi.

Coal mining activities must be followed by reclamation effort. If it had not done, environmental degradation would have occurred such as soil quality changes, not only physically but also chemically. Reclamation conducted by re vegetation on post coal mining land. This research aim to study physical and chemical soil properties on dumping of post coal mining. Method’s research is survey and laboratory analyze. Sampling method use the purposive sampling based on age of land. Soil sample was took as many 26 sample which were took in undisturbed condition, except texture analyze, using mold with 40 cm in length. Physical soil properties were analyzed is soil texture, moisture content, bulk density, porosity and water permeability. Chemical soil properties were analyzed is cation exchange capacity, organic matter, base saturation, available phosphor, nitrogen and available potassium. The result of this research showed that soil texture generally is clay. Moisture content have value about 15,17-39,56%. Bulk density of West of Pit 3 and North of Pit 1 (bench 4) have good class (1,20-1.29g/cm3), whereas East of Pit 3 and North of Pit 1 (bench 1) have bad class (1,46-1,72g/cm3). Porosity in East of Pit 3 is very low class (34,41-48%),whereas West of Pit 3 and North of Pit 1 (bench 4) is moderate (50,14-53%). Permeability is high class (0,0036- 0,0079cm/s). The higher the age of pile of soil, the better of bulk density, porosity, and permeability, whereas moisture content did not problem because mean rainfall in research area is high namely 3.040 mm. Cation exchange capacity have low to high class (10,98-38,57me/100g). Base saturation in East of Pit 3 is very high class (97,44-99,80%), whereas West of Pit 3 and North of Pit 1 is very low to low class (8,15-20,16%). Organic matter is very low to low class (0,57-3,45%). Available phosphor is moderate to very high class (20,31-43,67ppm). Nitrogen is very low to low class (0,01-0,12%). Available potassium generally is very high class (66,16-169,12ppm). Analyze result that prosperity degree based on chemical soil properties namely CEC, BS, OM and phosphor at research area have prosperity status is very low until very high.

Kata Kunci : Lingkungan Hidup,Kualitas Tanah,Sifat Fisik,Lahan Bekas Tambang, dumping, post coal mining, soil quality, physical soil properties, chemical soil properties