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.) 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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