Judul: An Anallysiis On Agrofforesttry Parttnershiip In Order To Miiniimiize Forestt Encroachmentt (Case Study of “Tumpangsari “for Food Crops at Plantation Forest Consession in Pulau Laut, South Kalimantan)
Abstrak: Forest degradation is becoming a very important issue with global warming . Broadly speaking, the functions of forests include economic, social, and ecological. Forest area in Indonesia covers approximately 133 million hectares, 31% of them are not vegetated (Ministry of Forestry 2011). The rate of deforestation in 2000-2009 covering 1.5 million hectares per year and the island of Borneo as the greatest contributor to deforestation of more than 36% (Sumargo et al. 2009). In 2011 forest area of 832 thousand hectares were degraded (Ministry of Forestry 2011). There is approximately 35% rural/urban or in and around the forest areas (Directorate General of Planology 2010). Surrounding community and in the forest in general farming by clearing forests for agriculture to meet their food needs. Increasing population and industrial forestry, plantation, mining has been narrowed the forest so area for cultivation fallow periods are shortened and degraded. The release of forest land for plantations encourage public access to forests penetrated by the limited acreage for farming (Setiawan 2010). The Law 41 of 1999 on Forestry explain occupation is clearing forest without permission from the authorities. Many of the overlapping licenses between central and local government policies due to the orientation of the respective interests (Kartodihardjo 2006) . Habits of the population around the forest to meet the food needs (subsistence) with a system of shifting cultivation is still the tradition by opening the forest. On the other hand there is plantation forest land ready for planting crops that can be used continuously for food crops. The objectives of the study was to explore the potential of forest land for agroforestry (“tumpangsari”) of food crops, forest encroachment analyzes, calculating the cost of production and revenue intercropping. The benefits of research are opening up opportunities in plantations for food crops without changing the function of forests, minimize conflict, increase stand growth and ensure food security . The study was conducted at forest plantations at Semaras and natural forests at Mekarpura, both in Pulau Laut and Senakin Kotabaru. Time study on rice planting season in October 2011-January 2013 (two season). Observations were made with the sample plot size of 2.5 x 2.5 meters by 20 plots at each site to measure productivity of rice plant. Measurements performed on plant growth trees in the sample plot locations intercropped and non-intercropped plants. Intercropping participant data retrieval, socio-economic and other demographic data conducted purposive sampling. The type of data in the form of primary data and secondary data. The primary data obtained from direct field measurements and interviews, while the secondary data obtained from various sources including the relevant agencies. The productivity of rice in “tumpangsari” model was 3.3 tones ha-1 which higher than that of in shifting cultivation area in secondary forest of about 3.1 tones ha-1 and significantly different. Shifting cultivation of rice production in the secondary forest at Pulau Laut and in Senakin 3.12 tons ha-1 and 3.173 tonnes ha-1respectively. Statistically productivity shifting cultivation of rice in both secondary forest sites were not significantly different . The cost of rice production amounting to Rp 5.932 million ha-1
Keyword: agroforestry, tumpangsari, plantation forest, encroachment, partnership

Judul: Comparative Feasibility Study of Rubber Agroforestry Business in Pelaihari Unit, Tanah Laut Regency, South Kalimantan
Abstrak: Pembangunan agroforestri sudah cukup lama dilaksanakan di Indonesia. Namun, sampai saat ini masih banyak tantangan pengelolaannya, salah satunya informasi skema agroforestri terbaik pada hutan tanaman industri yang masih terbatas. Pemanfaatan hutan karet di Unit Pelaihari Kabupaten Tanah Laut, Kalimantan Selatan milik PT. Inhutani III dikelola oleh dua perusahaan dengan skema agroforestri. Untuk itu, penelitian ini bertujuan menganalisis kelayakan finansial skema agroforestri yang telah dipraktikkan tersebut. Berdasarkan perhitungan analisis finansial, pengelolaan agroforestri karet, baik dengan tanaman sela singkong ataupun jagung adalah layak diusahakan. Namun, pada perbandingan per hektar usaha agroforestri karet, tanaman singkong memberikan nilai NPV, IRR, dan jangka waktu pengembalian (payback period) yang lebih baik dibanding tanaman jagung. Untuk itu, skema agroforestri karet layak diusahakan untuk pengembangan usaha, terutama dengan tanaman sela singkong. Manfaat yang didapat dari tumpangsari tidak hanya sebagai tanaman menghasilkan disaat tanaman utama belum menghasilkan, tetapi dapat meningkatkan pendapatan maksimum., Agroforestry development has been implemented in Indonesia for quite a long time. However, there are still many management challenges, one is the lack of information on the best agroforestry schemes in industrial plantation forests. PT. Inhutani III, in the Pelaihari Unit of Tanah Laut Regency, South Kalimantan, cooperates with two companies to utilize rubber forests under agroforestry schemes. In response, this study aimed to analyze the financial feasibility of the agroforestry scheme that has been practiced. Based on financial analysis, the management of rubber agroforestry with cassava or corn intercropping was feasible. However, in the ratio per hectare of rubber agroforestry business, cassava crops provided better NPV, IRR, and payback period values than corn crops. For this reason, the rubber agroforestry scheme is worth striving for business development, especially with cassava intercropping. The benefits derived from intercropping are not only as a yielding crop when the main crop is not yet harvested but can increase maximum income.
Keyword: agroforestry, financial analysis, plantation forest

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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