Judul: Effect of Water Conservation Treatment to Evapotranspiration of Oil Palm Plantation (Case Study : PT. SAWIT ASAHAN INDAH, Rokan Hulu, Riau).
Abstrak: Pembuatan rorak pada perkebunan kelapa sawit merupakan suatu teknik konservasi air yang dapat digunakan untuk mencukupi kebutuhan air tanaman. Rorak dibuat mengikuti kontur kemiringan lereng agar air hujan tidak terbuang menjadi aliran permukaan tetapi dapat mengalir ke dalam rorak dan menjadi cadangan air pada musim kemarau, serta meningkatkan simpanan air di permukaan tanah. Metode pengukuran dilakukan pada blok perlakuan (7, 8, 18) dan blok kontrol (6, 16, 17). Tiap blok dipasang 25 sensor kadar air tanah berdasarkan prinsip impedansi. Perhitungan evapotranspirasi dilakukan dengan menggunakan pendekatan neraca air yang didasarkan pada masukan dan keluaran air pada lahan tanaman kelapa sawit. Penelitian ini bertujuan untuk (i) mengetahui efektifitas penggunaan teknik konservasi air terutama pada lahan miring untuk menahan curah hujan yang menjadi simpanan air dan (ii) untuk menghitung kehilangan air melalui evapotranspirasi sebagai indikator kebutuhan air pada tanaman kelapa sawit. Hasil perhitungan evapotranspirasi menunjukkan bahwa, secara umum, Blok perlakuan memiliki cadangan air yang lebih besar dibandingkan Blok kontrol kecuali Blok 7. Blok 7 memiliki cadangan air sebesar 38 mm sedangkan terdapat Blok kontrol yang nilainya lebih besar, yaitu 55 mm (Blok 6). Hal ini disebabkan karena tingkat kemiringan lahan pada Blok 7 lebih curam dibandingkan Blok lainnya.
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Judul: Pengaruh Perlakuan Teknik Konservasi Air terhadap Evapotranspirasi Tanaman Kelapa Sawit (Studi kasus : PT. Sawit Asahan Indah, Rokan Hulu, Riau)
Abstrak: Water conservation by form of rorak (silt pit) is one of rainwater harvesting methods that can be applied in palm oil plantation to fulfill plants water requirements. Installation of rorak can increase surface water utilization and irrigation water use efficiency. This study aimed to analyze the effect of water conservation technique on soil water content and evapotranspiration of palm oil plantations. This research was conducted by measuring the soil water content in experimental blocks (7, 8, and 18) and control blocks (6, 16, and 17). Twenty five set soil moisture sensor devices were planted on each block. Soil water content was calculated by using soil water content calibration curves obtained through previous research. Evapotranspiration was calculated by using water balance approach in palm oil plantation. As the results, the level of soil water content and evapotranspiration in experimental blocks was higher than the control blocks. Daily average evapotranspiration in experimental and control blocks respectively were 3.9 mm and 3.7 mm. The values of water storage in experimental blocks except block 7 were greater than the water storage in control blocks.
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Judul: Grup dan Homomorfisma Grup pada Rubik Revenge
Abstrak: Rubik cube is a kind of puzzle game. A player must arrange rubik sides, which have been disordered, back to the position where every side has the same colour. This paper does not focus on the settlement solution, but instead on proving the existence of a group homomorphism between rubik movement group and S96 symmetric permutation group in rubik revenge. Firstly, it has been proved that rubik movement set is a group. Then, it also has been proved that the M set, which contains numeric labels of 1 until 96 in cubinos sides, is S96 symmetric permutation group.
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