Judul: Internalisasi Biaya Konservasi Lahan Pertanian Kentang Di Das Serayu (Studi Kasus Di Desa Igir Mranak, Kecamatan Kejajar, Kabupaten Wonosobo)
Abstrak: Environmental degradation caused by intensive potato farming on the upper Dieng Plateau has reached an alarming level. Farmers who intensively plant potatoes and other vegetables in this Plateu mostly do not apply soil and water conservation practices on their gardens. This is suspected as one of the main causes of high erosion and sedimentation rates in the watershed. These environmental problems combined with farmers’ behavior torwards soil and water conservation in their potato gardens require further attention and information on how to solve such problem. Therefore, this research offers some fundamental analysis on farm-budget under different conservation techniques, farmers’ willingness to accept in improving their conservation practices and potential of application of rewards for environmental services schemes in the upper Dieng Plateu. The objective of this study are (i) to evaluate the conservation practices of potato farming by comparing rate of erosion and farm productivity under different soil and water conservation techniques, (ii) to determine the Willingness to Accept (WTA) value to environmentally friendly farming practices for sedimentation reduction. The research involving 100 respondents was carried out in January–May 2011 at Igirmranak village, Wonosobo district, Central Java, Indonesia. The study shows that the total potato production on land without conservation techniques was 37% higher compared to the one with conservation techniques. This result is based on the measurement of the potato farming erosion rate that the conservation techniques could control erosion and run-off at higher rates (18.38% and 33.90% respectively) compared to potato farming without conservation techniques. Farmers who adopted conservation techniques experience less profit per season (IDR 5,905,021) than those who do not apply such technique. In contrast, the potato production per stem in conservation farming was 26% higher compared to production on land without conservation techniques. The study also showed that the value of WTA among farmers was IDR 5,000,000. Some factors that influenced them to make decisions were 1) bid amount and 2) perception of profitability of potato. Overall, this study concluded that the RES concept in Dieng could be implemented by setting enabling conditions for environmentally friendly agriculture system that could provide long-term benefits to farmers. Government involvement and support would be needed to provide livelihoods’ alternatives that can fill the gap between opportunity costs and WTA.
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Judul: The adoption of conservation farming system of potatoes farming in the dryland of Upland Pangalengan, Bandung
Abstrak: Soil erotion is a serious problem in upland Pangalengan, Bandung. A study was carried out to determine factors affecting adoption of conservation farming practices, to analize factors that influence its production and to analyze impact of conservation farming practices in soil fertility and potatoes farmer's income. The data for study analysis is collected from cross-sectional data of farm households.
Keyword: Soil conservation, Upland potatoes farming, Jawa Barat, Erosi, SCUAF, Pembangunan pertanian

Judul: Konstruksi Hukum Grup Kurva Eliptik Atas F3m
Abstrak: Elliptic curves upon F3m can be divided in two cases, i.e. supersingular and nonsupersingular case. Based on group laws on elliptic curves, a new arithmetic upon F3m can be formulated as an addition process of two random points on the curve. This addition process can then be applied to the ElGamal algorithm.
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