Judul: Perencanaan penggunaan lahan dan pengembangan usahatani berbasis kopi untuk sistem pertanian berkelanjutan di DAS Ketahun Hulu Provinsi Bengkulu
Abstrak: Ketahun Hulu watershed is part of Ketahun watershed, administratively it is mainly located in Lebong district and a small portion of it is located in North Bengkulu and Rejang Lebong districts of Bengkulu province. This study was aimed to identify landuse and agrotechnology characteristics in Ketahun Hulu watershed, and to arrange land use planning and coffee based farming development for sustainable agricultural systems in the Ketahun Hulu watershed. To achieve a sustainable agriculture, there are 3 (three) indicators that should be fulfilled : a) total farmer’s income should be high enough support a life worth living, b) erosion should be less than tolerable soil loss (ETol), c) agrotechnologies should be acceptable and replicable to the farmers. This study was focus on intensive observation sites covering 14,844 hectares located in one of sub watershed that represent characteristics of the watershed. Land capability was evaluated using Klingebiel and Montgomery method, erosion was predicted using USLE equation developed by Wishmeier and Smith (1978), and farming income was analyzed using cash flow analysis method. Results of this research showed that predicted erosion in the existing cropping pattern and agrotechnologies in Ketahun Hulu watershed generally greater than ETol; it ranged from 2,47 – 683,18 tons/hectare/year while ETol was ranged from 13,45 – 36,38 tons/hectare/year. Total incomes of farmers were much lower than a decent income (Rp. 18.000.000,-/householder/year). Alternative agrotechnologies to meet the indicators of sustainable agricultural systems were recommended with two alternatives. To increase farmer’s income to meet the income of decent living, the source of income such as livestock was introduced in to the existing farming systems. Simulation of agrotechnologies show that alternatives of agrotechnology can reduce erosion to lower than ETol and to increase farmer’s income up to a decent income. Alternative agrotechnolgy 1 which consisted of grass strip plus litter mulch, fertilizer and livestock including 30 chickens and 5 goats can reduce erosion to lower than ETol (2,45 – 22,77 tons/hectares/year) and increase farmer’s income up to a decent living (Rp. 18.855.000,- to Rp. 24.915.000,-/householder/year). Alternative agrotechnology 2 which consisted ridge terrace plus litter mulch, fertilizer and livestock including 30 chickens and 5 goats can reduce erosion to lower than ETol (2,47 – 22,77 tons/hectares/year) and increase farmer’s income up to a decent living (Rp. 18.635.000,- to Rp. 24.695.000,-/householder/year). Spatial planning of recommended agrotechnologies was extrapolated into the watershed in Ketahun Hulu Watershed.
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Judul: Perencanaan Penggunaan Lahan Berkelanjutan di Sub DAS Cisadane Hulu
Abstrak: Penduduk Sub DAS Cisadane Hulu yang sebagian besar adalah petani menggantungkan hidupnya dari lahan yang ada. Laju pertumbuhan penduduk yang cukup tinggi disertai dengan pendapatan yang rendah mengakibatkan tekanan terhadap lahan juga tinggi yang menyebabkan penggunaan lahan yang tidak sesuai dengan kemampuannya. Hal ini mengakibatkan kerusakan lahan dan pada akhirnya menyebabkan kesejahteraan masyarakat semakin menurun. Penelitian ini bertujuan mengkaji agroteknologi dan menyusun perencanaan penggunaan lahan berkelanjutan di Sub DAS Cisadane Hulu. Penetapan alternatif pola tanam dan agroteknologi dilakukan dengan simulasi model prediksi erosi USLE sehingga diperoleh lahan dengan nilai erosi (E) lebih kecil dari erosi yang dapat ditoleransikan (Etol). Rekomendasi pola tanam dan agroteknologi alternatif ditetapkan menggunakan analisa ekonomi pada berbagai pola tanam dan agroteknologi alternatif sehingga diperoleh pendapatan lebih besar dari pada standar hidup layak (SHL). Jika SHL tidak dapat dicapai dari berbagai pola tanam dan agroteknologi alternatif yang ada, maka ditambahkan alternatif pendapatan lain diluar sektor pertanian. Perencanaan penggunaan lahan berkelanjutan diperoleh berdasarkan kajian rekomendasi agroteknologi, peluang penerapan rekomendasi agroteknologi oleh petani, kajian manfaat ekonomi lingkungan pencegahan erosi untuk petani dan kajian program stakeholder terkait.
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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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