Abstract
PT. Dinamika Sejahtera Mandiri (PT. DSM) merupakan perusahaan swasta yang bergerak di bidang pertambangan bauksit dengan sistem penambangan terbuka, sehingga menghasilkan hamparan tanah dengan kandungan bahan organik dan unsur hara sangat rendah serta toksik tinggi sehingga lahan menjadi kritis. Upaya perbaikan lingkungan dilakukan dengan rehabilitasi lahan agar tidak menimbulkan kerusakan berkelanjutan. PT. DSM menggunakan penambahan biostimulan dalam rehabilitasi lahan, namun karena biaya yang mahal maka dilakukan alternatif menggunakan cocopeat sebagai pengganti topsoil dengan biaya terjangkau. Lokasi penelitian terletak di lahan pascatambang bauksit milik PT. DSM yang berada di Desa Teraju, Kecamatan Toba, Kabupaten Sanggau, Provinsi Kalimantan Barat. Total sampel tanah yang diuji sebanyak 23 sampel, terdiri dari 5 perlakuan dengan masing-masing perlakuan dilakukan pengulangan sebanyak 3 kali, yaitu perlakuan A tanpa perlakuan di lahan dengan topsoil, perlakuan B tanpa perlakuan di lahan tanpa topsoil, perlakuan C 100% cocopeat, perlakuan D 50% cocopeat + 25% arang sekam + 25% kotoran ayam dan perlakuan E 60% cocopeat + 25% arang sekam + 15% kotoran ayam. Hasil penelitian menunjukan kandungan parameter pH, % C- organik, KTK, dan N total dalam media tanam cocopeat memiliki kandungan yang lebih baik daripada topsoil dan tanah pascatambang, namun parameter P2O5, kadar debu, liat, dan pasir, topsoil memiliki kandungan yang lebih baik daripada cocopeat dan tanah pascatambang. Kandungan parameter fisik dan kimia terendah terdapat pada tanah pascatambang. Komposisi media tanam kombinasi cocopeat, arang sekam, dan kotoran ayam memiliki pengaruh yang baik terhadap pertumbuhan tanaman sengon karena memiliki unsur hara yang lebih baik dibandingkan dengan topsoil, tanpa topsoil atau hanya cocopeat saja. Dosis variasi paling optimal dalam pertumbuhan sengon dari segi pertumbuhan fisik tanaman yaitu pada variasi perlakuan kode tanam D, yaitu memiliki pertambahan tinggi tanaman rata-rata 13,7cm dan cabang daun sebanyak 6 helai yang lebih signifikan dibandingkan perlakuan media tanam lainnya. AbstractPT. Dinamika Sejahtera Mandiri (PT. DSM) is a private company engaged in bauxite mining with an open mining system, resulting in a stretch of land with very low organic and nutrient content and high toxicity so that the land becomes critical. Efforts to improve the environment are carried out by rehabilitating land so as not to cause sustainable damage. PT. DSM uses biostimulants in land rehabilitation, but an alternative is to use cocopeat as a substitute for topsoil at an affordable price because of the high cost. The research location is located on the bauxite post-mining land owned by PT. DSM is located in Teraju Village, Toba District, Sanggau Regency, West Kalimantan Province. Total soil samples tested were 23 samples, consisting of 5 treatments with each treatment being repeated three times, namely treatment A without treatment on land with topsoil, treatment B without treatment on the ground without topsoil, treatment C 100% cocopeat, treatment D 50% cocopeat + 25% husk charcoal + 25% chicken manure and treatment E 60% cocopeat + 25% husk charcoal + 15% chicken manure. The results showed that the pH,% C- organic, CEC, and total N content in the cocopeat growing medium had a better range than topsoil and post-mining soil. Still, the P2O5 parameters, the content of dust, clay, and sand, topsoil had better content. Then cocopeat and post-mining land. The lowest range of physical and chemical parameters is found in post-mining soil. The composition of the planting medium combination of cocopeat, husk charcoal, and chicken manure has a good effect on the growth of Sengon plants because it has better nutrients than topsoil, without topsoil, or just cocopeat. The most optimal dose of variation in the evolution of Sengon in terms of physical plant growth is the variation in the treatment of planting code D, which has an average plant height increase of 13.7 cm and six-leaf branches, which is more significant than the treatment of other growing media.