Judul: Fertilization Management of Palm Oil Plants (Elaeis guineensis Jacq.) on Mature Crops at Petapahan Estate, PT Peputra Masterindo, Kampar, Riau
Abstrak: Pemupukan merupakan bagian dari kegiatan utama dan sangat penting dalam pemeliharaan tanaman kelapa sawit. Kegiatan magang ini bertujuan untuk meningkatkan pengetahuan, keterampilan kerja dalam aspek teknis dan manajerial perkebunan sawit, dan menganalisis manajemen pemupukan tanaman kelapa sawit di Kebun Petapahan. Pengamatan aspek khusus dilakukan terhadap manajemen pemupukan di lapangan berdasarkan prinsip 5 tepat (tepat jenis, tepat dosis, tepat tempat, tepat waktu, dan tepat cara aplikasi) dan gejala defisiensi unsur hara pada tanaman kelapa sawit. Hasil pengamatan menunjukkan pemupukan di Kebun Petapahan pada ketepatan jenis pupuk KCL dan Borate, ketepatan dosis pupuk KCL, dan ketepatan tempat sudah sesuai dengan rekomendasi perusahaan yaitu sebesar 100%, 97,78%, dan 152,81 cm. Ketepatan cara aplikasi pupuk sudah cukup baik dengan persentase rata-rata 91,11%, namun pada pengamatan ketepatan dosis pupuk KCL masih dibawah standar aplikasi kebun yaitu 90,56%. Pengamatan ketepatan waktu aplikasi pupuk Urea, Rock phosphate, dan Dolomite masih belum sesuai dengan waktu aplikasi yang direkomendasikan. Pengamatan pada gejala defisiensi unsur hara menunjukkan bahwa di Kebun Petapahan terdapat 12% tanaman yang mengalami gejala defisiensi unsur hara kalium (K)., Fertilization is part of the main activity and is very important in the maintenance of oil palm plantations. This internship activity aims to improve knowledge, work skills in technical and managerial aspects of oil palm plantations, and analyze fertilizer management for oil palm plantations in Petapahan Estates. Observations of special aspects were carried out on fertilizer management in the field based on the right 5 principles (right type, right dose, right place, right time, and right application method) and symptoms of nutrient deficiency in oil palm plants. The results of the observations showed that fertilization in Petapahan Gardens on the accuracy of KCL and Borate fertilizer types, KCL fertilizer dosage accuracy, and location accuracy were in accordance with the company's recommendations, namely 100%, 97,78%, and 152,81 cm. The accuracy of the fertilizer application method is quite good with an average percentage of 91,11%, but the observation of the accuracy of KCL fertilizer dosage is still below the garden application standard, which is 90,56%. Observation of timeliness of application of Urea, Rock phosphate, and Dolomite fertilizers is still not in accordance with the recommended application time. Observations on the symptoms of nutrient deficiency showed that in Petapahan Gardens there were 12% of plants that experienced symptoms of potassium (K) nutrient deficiency.
Keyword: nutrient deficiency, recommendation, proper fertilization

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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