Judul: Technique of cover crop development on coal mining reclamation as pasture
Abstrak: Land reclamation usually characterized by low of soil fertility. If it will be utilized as a pasture, it required soil amendment such as arbuscular mycorrhizal fungi (AMF), liquid compost, and appropriate grazing management. Seed coating technology with mycorrhizal root and liquid compost have expectation on soil amendment application in coal mining reclamation. Utilization of this pasture should be considered the stocking rate or the number of cattle grazed in the pasture. The objectives of the research were to find out the proper of inoculation techniques of AMF on signal grass (Brachiaria decumbens) and puero legume (Pueraria phaseoloides), concentration and frequency of liquid compost applied, herbage production on mix culture between signal grass and puero, and stocking rate of signal grass and puero mix pature on coal mining reclamation. Four experiments were applied in this research, and was conducted in PT Kaltim Prima Coal (KPC), Sengata, Kalimantan Timur. The first experiment was inoculation techniques of arbuscular-mycorrhizal fungi on Brachiaria decumbens and Pueraria phaseoloides, the second experiment was concentration and frequency of liquid compost applied to mycorrhizal Brachiaria decumbens and Pueraria phaseoloides, the third experiment was mix culture production of mycorrhizal Brachiaria decumbens and Pueraria phaseoloides amended by liquid compost, and fourth experiment was Animal Production in Mix Pasture of Brachiaria decumbens and Pueraria phaseoloides at Coal Mining Reclamation Land. The first and second experiment was done in greenhouse, whereas third and fourth experiment was done in mine reclamation field.
Keyword: stocking rate, liquid compost, B. decumbens, P. Phaseoloides, arbuscular michorrhizal fungi

Judul: Increasing the Carrying Capacity of Post-Coal Mining Grazing Fields with Different Doses of Urea Fertilization
Abstrak: Penelitian ini bertujuan mengetahui pengaruh dosis pemupukan urea dan pemotongan yang berbeda terhadap pertumbuhan dan produktifitas rumput Brachiaria decumbens dalam meningkatkan kapasitas tampung di padang penggembalaan lahan pasca tambang batu bara. Penelitian menggunakan rancangan acak kelompok faktorial (RAKF) dengan dua faktor yaitu faktor A terdiri dari T1 = Pemotongan 5 cm dari permukaan tanah; T2 = Pemotongan 10 cm dari permukaan tanah. Faktor B terdiri dari P0 = Kontrol; P1 = Urea 100 kg ha-1; P2 = Urea 200 kg ha-1; P3 = Urea 300 kg ha-1. Parameter yang diuji adalah komposisi botani, kapasitas tampung existing dan peningkatannya, Proper Use Factor (PUF), produksi protein, tinggi, diameter, dan biomassa tanaman. Hasil penelitian kapasitas tampung existing sebesar 1,01 ST ha-1. Pemupukan urea berpengaruh terhadap diameter, biomassa tanaman, peningkatan kapasitas tampung dan produksi protein. Perlakuan T2 dan P2 efektif menghasilkan nilai PUF sebesar 66,30% dan meningkatkan kapasitas tampung menjadi 1,70 ST ha-1., This research aimed to determine the effect of different doses of urea fertilization and mowing on the growth and productivity of Brachiaria decumbens grass in increasing carrying capacity in pastures on post-coal mining land. The research used a randomized block factorial design (RBFD) with two factors, namely factor A consisting of T1 = Cutting 5 cm from the ground surface; and T2 = Cutting 10 cm from the ground surface. Factor B consists of P0 = Control; P1 = Urea 100 kg ha-1; P2 = Urea 200 kg ha-1; P3 = Urea 300 kg ha-1. The parameters tested were botanical composition, existing and increasing capacity, Proper Use Factor (PUF), protein production, height, diameter, and plant biomass. The research results showed that the existing carrying capacity is 1.01 AU ha-1. Urea fertilization affected diameter, plant biomass, increased carrying capacity, and protein production. Treatment of T2 and P2 was effective in produced a PUF value by 66.30% and increased the carrying capacity to 1.70 AU ha-1.
Keyword: botanical composition, carrying capacity, Proper Use Factor, urea fertilizer

Judul: Formulasi Hamilton Untuk Menggambarkan Deformasi Gelombang Soliter Dengan Dasar Tidak Rata Pada Fluida Dua Lapisan
Abstrak: Gelombang internal adalah suatu gelombang yang muncul di bawah permukaan laut sehingga gelombang ini tidak teramati secara kasat mata. Formulasi Hamilton dirumuskan untuk menjelaskan gerak gelombang ini. Dalam hal ini diasumsikan bahwa fluida yang ditinjau terdiri atas dua lapisan dengan masing-masing lapisan memiliki rapat massa yang konstan. Selain itu, diasumsikan pula fluida yang ditinjau berupa fluida tak mampat (incompressible) dan tak kental (invicid). Formulasi Hamilton dilakukan dengan meninjau fluida dua lapisan yang berada pada domain yang dibatasi oleh batas atas yang rata dan batas bawah yang tidak rata. Hamilton (energi total)-nya didefinisikan sebagai penjumlahan antara energi kinetik dan energi potensialnya. Karena energi kinetik tidak secara eksplisit dinyatakan dalam peubah fisis, maka digunakan metode asimtotik untuk menentukan energi totalnya. Dalam hal ini diasumsikan bahwa gelombang interfacial yang ditinjau cukup panjang, dan amplitudo yang cukup kecil. Persamaan Korteweg de- Vries (KdV) diperoleh, jika disumsikan bahwa gelombang interfacial hanya merambat pada satu arah, sedangkan jika gelombang tersebut merambat ke dua arah, diperoleh persamaan Boussinesq.
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