Judul: Aplikasi Pupuk Organik Cair Urin Kelinci untuk Peningkatan Pertumbuhan dan Hasil Produksi Caisim (Brassica juncea L.) Organik di Yayasan Bina Sarana Bakti, Cisarua, Bogor, Jawa Barat
Abstrak: Kegiatan magang ini dilaksanakan di Kebun Organik Yayasan Bina Sarana Bakti (YBSB), Cisarua, Bogor, Jawa Barat. Tujuan magang ini secara umum adalah untuk meningkatkan pengetahuan dan keterampilan mahasiswa baik teknis maupun manajerial dalam kegiatan produksi sayuran organik. Secara khusus kegiatan magang ini bertujuan untuk mempelajari pengaruh konsentrasi pupuk organik cair urin kelinci terhadap pertumbuhan dan hasil produksi sayuran caisim secara organik. Data primer diambil melalui percobaan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) 1 faktor dengan 4 taraf urin kelinci (0, 5, 10, dan 15%) dan 3 ulangan sehingga terdapat 12 satuan percobaan. Tanaman caisim dikombinasikan dengan selada merah dengan letak 3 baris tanaman caisim dan 2 baris selada merah di sisi kanan dan kirinya. Kegiatan produksi sayuran organik di YBSB secara keseluruhan telah berjalan dengan baik. Kegiatan magang ini mampu meningkatkan pengetahuan serta keterampilan penulis baik dari segi teknis maupun manajerial dalam budidaya sayuran organik. Aplikasi pupuk organik cair urin kelinci pada 1 minggu setelah tanam nyata meningkatkan pertumbuhan vegetatif tanaman caisim diantaranya jumlah, daun, panjang daun, lebar daun dan diameter batang. Konsentrasi urin kelinci 10% adalah konsentrasi terbaik untuk diaplikasikan pada tanaman caisim. Konsentrasi ini nyata meningkatkan bobot basah dan bobot rompesan caisim yang dipanen. Meskipun secara statistik ketiga perlakuan konsentrasi tidak menunjukkan perbedaan yang nyata, namun konsentrasi POC 10% menghasilkan rataan nilai tengah bobot layak jual tertinggi dengan persentase peningkatan sebesar 72.87%, sehingga dapat dijadikan sebagai pilihan terbaik karena lebih menguntungkan dari segi ekonomi.
Keyword: akar gada, limbah, ramah lingkungan, sawi hijau, sayuran

Judul: Pengaruh pupuk organik cair pada produksi dan serapan hara tanaman Caisim (Brassica juncea) varietas Tosakan pada Latosol Darmaga
Abstrak: Indonesia is situated in tropical region with high rainfall and temperature. These high rainfall and temperature affect the soil fertility through intensive weathering and leaching process. Leaching process could lead the decrease of basic cations and other important elements for plant. Further it makes soils in Indonesia acid and infertile. One of ways to improve the soil fertility is the application of fertilizer. The fertilizers could be applied through leaf and soil. Leaf fertilizer is applied by using foliar feeding method directly to the leaf so the essential nutrient absorbed by itself through the leaf. Leaf fertilizer is in liquid form, enrich by macro and micro nutrients. The objectives of this research were to determine the effect of liquid organic fertilizer to the yield, nutrient content and nutrient uptake of nitrogen (N), phosphorus (P) and potassium (K) of the caisim (Brassica juncea). This research also aims to determine the effectiveness of fertilizer that is measured by Relative Agronomic Effectiveness (RAE). The experiment was conducted in the greenhouse of University Farm in Cikabayan, Bogor. Analysis concerning nutrient content and plant uptake of N, P and K were carried out in Chemical and Soil Fertility Laboratory, Agricultural Faculty, IPB. Greenhouse expriment was set up in Completely Randomize Design (CRD) with seven treatments and four replications The treatments were as follows: control, standard (S), 0,75PO+0,5S, 0,75PO+0,75S, 1,0PO+0,5S, 1,0PO+0,75S, dan 1,25PO+0,5S. Standard was the treatment using Urea, SP-36 and KCl fertilizers with the rates 200kg/ha, 300kg/ha and 100 kg/ha respectively. PO in the treatments label referred to leaf organic fertilizer while S referred to standard. As for liquid organic fertilizer, the recommended rate was 5 L/ha. The result showed the addition liquid organic fertilizer (PO) and standard fertilizer in lower dose (0,5S and 0,75S) effective in improving the yield of caisim. Nutrient uptake (N and K) in these treatments (0,75PO+0,75S and 1,0PO+0.75S) tended to have higher value than the standard. Meanwhile nutrient uptake (P) in combine dose of PO and S have higher value than standard. In RAE value, the combine dose gave a higher tendency than the standard, whereas this combine dose of treatment (1,0PO+0,5S) resulted in higher value than those of others treatments. Based of the results and considering the RAE values, it suggested that treatment of 1,0PO+0,5S was recommended as fertilizer dose that should be applicated.
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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.
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