Judul: Growth and Production of Sugarcane (Saccharum officinarum L.) First Ratoon in Residual Filter Cake and Inorganic Fertilizer.
Abstrak: Intensifikasi tebu keprasan lahan kering merupakan salah satu cara dalam rangka meningkatkan produksi gula nasional. Penelitian dilakukan bulan Agustus 2019 - Juli 2020 pada tebu keprasan pertama di lahan percobaan PT Kebun Tebu Mas, Lamongan, Jawa Timur dengan rancangan split split plot. Perlakuan terdiri atas 3 faktor yaitu varietas (PS 881 dan PS 862) sebagai petak utama, residual kompos blotong (taraf residual pupuk blotong 0, 5, dan 10 ton ha-1) sebagai anak petak, dan residual pupuk anorganik (residual pupuk 25%, 50%, 75%, dan 100% dosis rekomendasi) sebagai anak-anak petak. Hasil penelitian menunjukkan bahwa pertumbuhan varietas PS 862 lebih baik daripada PS 881 pada keragaan tinggi tanaman, panjang ruas, diameter, panjang batang, dan jumlah batang. Residual kompos blotong memiliki pengaruh nyata lebih baik pada taraf 10 ton ha-1 pada panjang ruas. Residual pupuk anorganik taraf 75% memiliki respon yang lebih baik pada peubah jumlah daun, jumlah tunas, jumlah batang dan diameter. Varietas PS 862 dengan 5 ton ha-1 residual kompos blotong menghasilkan bobot batang terbaik sebesar 0,48 kg m-1. Varietas PS 862 dengan 75% residual pupuk anorganik menghasilkan hasil tebu sebesar 78,52 ton ha-1 dan tidak berbeda nyata dengan residual 100% pupuk anorganik., Intensification of upland sugarcane is one way to increase national sugar production. The research was conducted in August 2019-July 2020 on the experimental field of PT Kebun Tebu Mas, Lamongan on the first ratooncane with a split-split plot design. The treatment consisted of three factors, variety (PS 881 and PS 862 as main plots), residual filter cake (0, 5, and 10 tons ha-1) as subplots, and inorganic fertilizer residues (25, 50, 75, and 100% recommended doses) as subsubplots. The results showed that growth and yield of PS 862 was better than PS 881 in the performance of plant height, internode length, diameter, stem length, and number of stems. The residue of blotong compost had a significantly better effect at the level of 10 tons ha-1 on internode length. Residual inorganic fertilizer level 75% had a better response to the variables of number of leaves, number of shoots, number of stems and diameter. The PS 862 with 5 tons ha-1 residual blotong compost produced the best stem weight of 0.48 kg m-1. The PS 862 variety with 75% residual inorganic fertilizer produced sugarcane yields of 78.52 tons ha-1 and was not significantly different from the residual 100% inorganic fertilizer.
Keyword: intensification, PS 881, PS 862, sugar, upland

Judul: Budidaya tebu (Saccharum officinarum L.) lahan kering di PG Madukismo PT Madubaru Yogyakarta dengan aspek khusus pemupukan beberapa kategori tanaman tebu lahan kering
Abstrak: The internship was conducted at PG Madukismo PG Madubaru Yogyakarta beginning 14 February 2012 to 15 Mei 2012. The special purpose is study fertilization of some category of upland sugarcane at PG Madukismo PT Madubaru Yogyakarta. Fertilization in PG Madukismo is important because one in order to achieve high productivity is a good fertilizer. Most of the fields in the PG Madukismo was upland. There are two types of cultivated sugar cane that is PC (Plant Cane) and RC (Ratoon Cane) Fertilizer used in PG Madukismo is the dose recommended by the P3GI and considered by PG Madukismo and farmers. Parties responsible for the extraction of manure from the barn to the application to sugarcane was foreman and field assistant. Dosage fertilizer for PC (Plant Cane) are 11 ku/ha Madros, 5 ku/ha ZA and 5 ku/ha Phonska while for RC (Ratoon Cane) are 5 ku/ha ZA and 5 ku/ha Phonska. The data obtained were analyzed using t-test. From the results obtained for plants PC or RC I obtained the best productivity of sugarcane grown on land that has a typology mild soil type, irrigation well (pump) and the current drainage there are Kledokan field in Magelang which have productivity 598 ku /ha and Sikendal field in Temanggung which have productivity 693 ku/ha.
Keyword: 

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
Keyword: