PEMANFAATAN BLOTONG DAN FOSFAT ALAM PADA TANAMAN ROSELA DI LAHAN PODSOLIK MERAH KUNING KALIMANTAN SELATAN - SANTOSO, BUDI; SASTROSUPADI, ADJI; DJUMALI, . (Jurnal Penelitian Tanaman Industri, 2003)
Hasil samping dari limbah pabrik gula diantaranya adalah blotong atau dikenal dengan scbulan "ilter press mud". Secara umum bentuk dari blotong berupa serpihan scrat-scrat tebu yang mempunyai komposisi humus, N-total, C/N, P2O5, K20, CaO dan MgO, cukup baik untuk dijadikan bahan pupuk organik. Blotong dapat memperbaiki isik tanah, khususnya meningkatkan kapasitas menahan air. menurunkan laju pencucian hara dan memperbaiki drainase tanah. Manfaat lain dari blotong dapat menetralisir pengaruh Al<u , sehingga ketersediaan P dalam tanah lebih tersedia. Tujuan penelitian adalah untuk mendapatkan dosis blotong dan pupuk fosfat alam yang sesuai pada tanaman rosela di lahan podsolik merah kuning Kalimantan Selatan. Penelitian dilaksanakan di senlra pengembangan Intensiikasi Serat Karung Rakyat yaitu di daerah tranmigrasi Desa Sabuhur II, Kecamatan Jorong, Kabupaten Tanah Laut, Kalimantan Selatan dari bulan September 1998 sampai dengan bulan April 1999 Kctinggian lempal 50 m di atas permukaan air laut dengan tipe iklim B2 yaitu 2-3 bulan kering dan 7-9 bulan basah. Topografi dataran rendah dan tadah hujan. Perlakuan disusun dalam rancangan acak kelompok faktoial yang diulang sebanyak 3 kali. Sebagai faktor petama adalah blotong dengan dosis : 3, 4, dan S ton per hektar, sedang faktor kedua pupuk fosfat alam dengan dosis : 40: 60, 80, dan 100 kg P,Oj per hektar. Seluruh perlakuan terdiri dari 12 kombinasi blotong dan fosfat alam Ukuran petak yang digunakan 4 m x 6 m dengan jarak tanam 20 cm x 20 cm. Setiap lubang lanam bcrisi satu tanaman Hasil penelitian menunjukkan bahwa pemberian 5 ton blolong + 40 Pj05 per hektar ditambah dengan pupuk dasar 90 kg N * 60 kg K2O menghasilkan pertumbuhan linggi tanaman, diameter batang, berat brangkasan, berat kulil, hasil serat kering dan kckuatan serat rosela, masing-masing sebesar 336.35 cm; 14.73 mm; 536 kg/petak; 147 50 kg'petak; 2.775 ton per hektar dan 31 50 granvtex.Kala kunci: Rosela, blotong, fosfal alam, podsolik merah kuning, KalimantanÂ ABSTRACT The use ofilter press mud and rock phosphate on roselle cultivation in red yellow podsolic soil in South KalimantanThe waste of sugarcane factory was blotong or called "ilter press mud". As an organic fetilizer, blotong contains C, N-total, C/N, P2OJ, K2O, CaO and MgO. The filter press mud is believed to have the capacity in improving soil physic, especially water rclcntion, leaching ability and drain capacity. Orther advantage is that it is capable of netralizing the effect of exchangable Al, thus improving the soluble P in the soil. The improvement in soil physic due to the application of ilter press mud is expected to increase the crop yield The purpose of this experiment was to ind out the appropriate dose of iller press mud and rock phosphate on roselle cultivation in the red yellow podsolic soil in South Kalimantan The experiment was conducted in the central growing areas in red yellow podsolic soil al the Sabuhur II transmigration silc, Jorong Sub District, Tanah I-aut District, South Kalimantan Province from September 1998 to April 1999 Location attitude was 50 m above sea level and climate type was B2 with 7-9 wet months and less 2-3 dry months. The topography was low land with rain fed land The experiment was arranged factorially in a randomized block design with three replications. The irst factor was filter press mud with a rate of 3; 4 and 5 Ions per hectare While the second factor was rock phosphate with the rate of 40; 60; 80, and 100 kg P;0> per hectare. The treatments were 12 ertilizer combination of filler press mud Plating space was 20 cm x 20 cm and Ihe plot size was 4 m x 6 m with one plant per hole 'Die result showed that 5 tons filter press mud * 40 kg P2Oj rock phosphate per hectare and added with 90 kg N ^ 60 kg K2O gave the best performance The plant height, stem diameter, fresh weight, bark weight, iber yield and iber strength were 336.35 cm; 14.73 mm; 536 kg/plot; 147.50 kg/plot; 2 775 tons per hectare and 31.50 gram/tex respectivelly.Key words : Roselle, ilter press mud, rock phosphate, red yellow podsolic, Kalimantan