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.) at Inti Utara Plantation, PT Peputra Masterindo, Kampar, Riau
Abstrak: Pemupukan merupakan salah satu bagian penting dari budidaya kelapa sawit dan bertujuan menjaga tanaman kelapa sawit agar sehat sehingga berproduksi optimal. Tujuan umum kegiatan magang adalah mempelajari aspek teknis, manajerial budidaya kelapa sawit, bertujuan khusus mempelajari pemupukan kelapa sawit meliputi manajemen perencanaan, pelaksanaan, dan evaluasi pemupukan. Kegiatan magang dilaksanakan di Kebun Inti Utara Petapahan, PT Peputra Masterindo, Kabupaten Kampar, Riau, pada bulan Januari hingga Mei 2021. Pengamatan dilakukan secara langsung meliputi aspek 5 T (tepat jenis, tepat dosis, tepat waktu, tepat tempat, tepat cara), kehilangan pupuk, dan keterampilan kerja. Data yang diperoleh dianalisis secara deskriptif dan kuantitatif meliputi rata-rata (dosis, cara, tempat pemupukan, gejala defiseinsi hara), dan persentase hasil pengamatan. Hasil rata-rata diuji menggunakan t-student dan uji-f tukey pada taraf 5%. Aplikasi pemupukan tepat jenis, tepat tempat, dan tepat cara sudah dilaksanakan dengan baik sesuai standar perusahaan, tetapi pada aplikasi pemupukan tepat dosis dan waktu belum sesuai dengan standar perusahaan. Rata-rata jarak penaburan pupuk yang dilakukan sebesar 152,73 cm lebih tinggi dari standar perusahaan 150 cm pada area tanaman menghasilkan, sedangkan rata-rata 48,15 cm lebih rendah dari standar perusahaan 50 cm pada area tanaman belum menghasilkan. Realisasi waktu pemupukan masih belum sesuai dengan standar karena aplikasi pupuk selain KCl dan borate tidak dilakukan sesuai rencana. Gejala defisiensi hara yang terjadi didominasi pada unsur hara K dengan nilai 8,67% pada sampel TM dan 5,33% pada sampel TBM. Kehilangan pupuk di Kebun Inti Utara Petapahan masih dapat ditoleransi dengan nilai kehilangan 2%. Pengalaman kerja berpengaruh pada keterampilan kerja pada saat aplikasi pemupukan., Fertilization is an important part of oil palm cultivation. It is aimed at keeping the oil palm plants healthy and productive. The general objective of this activity is studying the technical and managerial aspects of oil palm cultivation. The specific objectives of studying oil palm fertilization are planning management, implementation, and evaluation of fertilization. The internship activity was undertaken at Petapahan North Core Plantation, PT Peputra Masterindo, Kampar Regency, Riau, from January to May 2021. The observation is conducted directly on 5 T aspects (right type, right dose, right time, right place, right method), fertilizer loss, and work skill. The data was analyzed descriptively and quantitatively. It included the average (dose, method, place of fertilization, symptoms of nutrient deficiency), and the percentage of observation. The average results were tested by using the t-student and Tukey's f-test at the 5% level. The application of the right fertilizer, the right place, and the right way had been implemented well according to the company standard. Meanwhile, the application of fertilizer at the right dose and time was not accordance with the company standard. The average spacing of fertilizers was 152.73 cm higher than the company's standard of 150 cm in mature plantation areas, while the average was 48.15 cm lower than the company's standard of 50 cm in immature plantation areas. The realization of fertilizing time was not up to the standard yet because the use of fertilizer other than KCl and borate was not carried out to the plan. The symptoms of nutrient deficiency were dominated by K nutrients with a value of 8.67%
Keyword: palm oil, precision, losses, work skills

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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