Judul: . Fertilization Management of Oil Palm (Elaeis guineensis Jacq.) at Tanah Gambus Estate PT Socfin Indonesia North Sumatera.
Abstrak: Fertilization management plays an important role in operating oil plant plantation because it affects productivity and highly contribute to production cost. The internship acvtivity was carried out from February to march 2020 at Tanah Gambus Plantation, PT Socfin Indonesia, North Sumatera. The purpose of the internship is to enrich working experience with getting involved in technical and managerial aspects in managing oil palm plantation. The observations related to fertilizing activities were planning, organizing, and applying fertilizer in the field. Fertilization must be done effectively and efficiently to fulfill the nutrient needs of the plants. The observations that were done on the management of fertilizing in the field is based on 5R principles (right kind of fertilizer, right dose, right time, right place, and right method), also considering the work performance. The application of fertilization at Tanah Gambus Plantation has been implemented according to the 5R principles as company standars, and the planning and organization of the fertilizing workforce is also in accordance with the standards set by the company. The observations of fertilizing in terms of the right kind of fertilizer, right time, and right method of application were carried out by comparing the application in the field with the plan and fertilization standards that have been set. The observation of fertilizing in term of the right place was observed in 3 blocks for each kind of fertilizer with 75 plants for each block. The observation of dosage was carried out on the bag of fertilizer and application by workers in the field. The percentage of precision fertilization based on 5R principles at Tanah Gambus Plantation was more than 90%. This result means that the organization and supervision of the application of fertilization has been carried out properly., Manajemen pemupukan berperanan penting dalam pengelolaan kebun karena pengaruhnya terhadap capaian produktivitas dan kontribusinya yang besar terhadap pembiayaan. Kegiatan magang dilaksanakan pada bulan Februari hingga Maret 2020 di Kebun Tanah Gambus PT Socfin Indonesia, Sumatera Utara. Tujuan kegiatan magang adalah memberikan pengalaman kerja dengan terlibat dalam aspek kegiatan teknis dan managerial pengelolaan tanaman kelapa sawit. Pengamatan yang dilakukan terkait pemupukan meliputi perencanaan, pengorganisasian, dan pengaplikasian pupuk di lapangan. Pengamatan yang dilakukan pada manajemen pemupukan di lapangan berdasarkan kaidah 5T (tepat jenis pupuk, tepat dosis, tepat waktu, tepat tempat dan tepat cara), serta prestasi kerja pemupuk. Pengamatan di lapangan menunjukkan bahwa kegiatan pemupukan di Kebun Tanah Gambus telah menerapkan kaidah 5T sesuai dengan standar yang telah ditetapkan oleh perusahaan. Demikian juga perencanaan dan pengorganisasian tenaga kerja pemupukan telah sesuai dengan standar perusahaan. Pengambilan data tepat jenis, tepat waktu, dan tepat cara dilakukan dengan membandingkan pengaplikasian pemupukan di lapangan dengan rencana dan standar pemupukan yang telah ditetapkan. Pengambilan data tepat tempat dilakukan pada 3 blok untuk tiap jenis pupuk dengan masing- masing 75 tanaman untuk tiap bloknya. Pengamatan tepat dosis dilakukan pada karung untilan dan aplikasi oleh pekerja di lapangan. Persentase ketepatan kaidah 5T di kebun Tanah Gambus berada di atas 90%, hal ini menunjukkan pengorganisasian dan pengawasan terhadap pengaplikasian pemupukan telah dilaksanakan dengan baik.
Keyword: worker performance, fertilization principles, managerial aspect, technical aspect

Judul: Fertilization Management of Palm Oil (Elaeis guineensis Jacq.) in Negeri Lama Selatan Estate, PT Hari Sawit Jaya, Labuhanbatu, North Sumatera
Abstrak: Kelapa sawit merupakan tanaman perkebunan penting yang potensial untuk dibudidayakan. Pemeliharaan pada tanaman kelapa sawit khususnya pemupukan memerlukan biaya yang tinggi sehingga perlu diperhatikan peningkatan efisiensi dan efektivitas pada penerapannya. Kegiatan magang dilaksanakan di Kebun Negeri Lama Selatan, PT Hari Sawit Jaya, Labuhanbatu, Sumatera Utara yang berlangsung dari Januari-Mei 2022. Kegiatan magang bertujuan untuk mempelajari dan menganilisis sistem manajemen pemupukan kelapa sawit yang efektif dan efisien. Pengamatan pada manajemen pemupukan dilakukan pada penerapan kaidah 5T (tepat jenis, tepat dosis, tepat cara, tepat waktu dan tepat tempat). Berdasarkan hasil pengamatan, manajemen pemupukan di Kebun Negeri Lama Selatan sudah dijalankan dengan baik sesuai dengan standar yang ditetapkan oleh perusahaan. Penerapan sistem tempat pengeceran pupuk meningkatkan kualitas pemupukan dan mempermudah proses pelangsiran pupuk. Ketepatan dosis aplikasi pupuk pada pemupukan HGFB (High Fertilizer Borate) mencapai persentase 95.50% dan pada pemupukan MOP (Muriate of Potash) mencapai persentase dan 92.80%. Realisasi aplikasi pupuk sudah sesuai dengan rekomendasi waktu pemupukan. Cara pengaplikasian pupuk juga sudah baik, ratarata persentase tepat cara pemupukan HGFB dan MOP yaitu 95,50% dan 92,10%. Tempat pemupukan juga sudah diaplikasikan sesuai standar perusahaan, rata-rata jarak aplikasi pupuk dari pokok pada pemupukan HGFB dan MOP yaitu 54,88 cm dan 52,90 cm., Palm oil is an important plantation crop that has the potential to be cultivated. Maintenance of palm oil, especially fertilization, requires high costs, so its necessary to pay attention to increasing efficiency and effectiveness in its application. The internship was conducted on January to June 2022 at Negeri Lama Selatan Estate, North Sumatera. The internship activity aims to study and analyze an effective and efficient oil palm fertilization management system. Observations on fertilization management were carried out on the application of the 5T rule (right type, right dose, right method, right time and right place). Based on observations, fertilization management in Negeri Lama Selatan Estate has been carried out well according to the standards set by the company. The application of a fertilizer retailing system improves the quality of fertilization and simplifies the process of fertilizer distribution. The accuracy of fertilizer application dose on HGFB (High Grade Fertilizer Borate) fertilization reached the percentage of 95.5% and the MOP (Muriate of Potash) fertilization reached the percentage and 92.80%. The realization of fertilizer application is in accordance with the recommended time of fertilization. The method of applying fertilizer is also good, the average persentation of HGFB and MOP fertilization methods is 95.50% and 92.10%, respectively. The place of fertilization has also been applied according to company standards.
Keyword: cara pemupukan, efisiensi pemupukan, ketepatan pemupukan, fertilizer accurancy, fertilizer application, fertilizer efficiency

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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