Judul: Land Suitability Criteria for Maize and Groundnut Based Land Utilization Types in the Bogor Area, Kriteria kesesuaian lahan untuk tipe penggunaan lahan berbasis jagung dan kacang tanah di daerah Bogor
Abstrak: The existing criteria of land suitability classification for maize and groundnut which have been used to evaluate of land suitability in Indonesia are too general and not used on spesified location of upland agriculture. The parameters and their ratings in the criteria were not tested and verified in the field especially their relationship to the production of crops, therefore the results of land suitability evaluation were often not suited to the potential of land and expected yields. The objectives of the research are: (1) to study the influence of variability of parent materials and soil development to land qualities and crop productivity of maize and groundnut, (2) to identify the limiting factors of defined landuse and minimum data set of land qualities for land suitability evaluation in the wet climate of upland agriculture, and (3) to create the land suitability criteria for maize and groundnut based land utilization types with low and medium inputs. Variability of parent materials and soil development strongly influenced the land qualities of nutrient retention and toxicity which are determined by land characteristics of pH, base saturation, and exchangeable aluminum. Land quality of nutrient availability, especially of available P, much more influenced by land management. The production of maize and groundnut on the low and medium input of the land utilization types were varied and influenced by variability of those parent materials and their soil developments. The crop productions on medium input were higher and significantly differed from the low input. The advanced stage of soil development tended to decrese the land qualities and crop productions. Productivity of the wet climate of upland agriculture was strongly influenced by the land qualities of nutrient availability, nutrient retention and toxicity. The production of maize on the low input was determined by land characteristics of pH, available P, and exchangeable aluminum, and the groundnut by available P, base saturation, and exchangeable aluminum. On the medium input, the crop production of maize is influenced by the land characteristics of pH and exchaneable aluminum, and the production of groundnut by the land characteristics of BS and exchangeable aluminum. The land suitability criteria for the defined land utilization types are created on base of: (1) the relevant land qualities, and (2) crop productivity of the area. By using the criteria indicate that the land suitability classes are suitable to the area and expected yields of the defined land utilization type. In case of the study area, the land qualities and land characteristics needed in the criteria are fewer than the existing criteria and therefore the processing of the land suitability evaluation could be done faster, easily and gave an accurately results. Especially, on the very acid soils developed on the acid sedimentary rock must be applied by fertilizer, organic matter and liming to improve land qualities of the soils., Kriteria kesesuaian lahan untuk tanaman jagung dan kacang tanah yang telah ada untuk keperluan evaluasi kesesuaian lahan di Indonesia masih sangat umum dan tidak untuk spesifik lokasi. Parameter yang digunakan dan pengharkatannya belum dikaji di lapangan dan dihubungkan dengan produksi tanaman, sehingga seringkali terjadi hasil
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Judul: Pemodelan perubahan penggunaan lahan dengan pendekatan Artificial Neural Network (Studi Kasus: Kabupaten Sukabumi, Jawa Barat)
Abstrak: Evaluasi kesesuaian tidak cukup jika hanya dilakukan secara fisik, tetapi harus diimbangi dengan evaluasi kelayakan ekonomi untuk menunjang sistem usaha tani. Evaluasi lahan secara ekonomi dapat memberikan gambaran finansial dari suatu komoditas yang dikembangkan. Tujuan penelitian ini adalah mengetahui karakteristik lahan, melakukan evaluasi kesesuaian lahan secara fisik dan ekonomi untuk beberapa tanaman pangan (padi sawah, jagung, kedelai dan kacang hijau). Penelitian ini dilakukan 10 kecamatan di Kabupaten Karawang yaitu Kecamatan Banyusari, Cikampek, Cilamaya Kulon, Cilamaya Wetan, Jatisari, Kota Baru, Lemahabang, Purwasari, Tempuran dan Tirtamulya. Luas wilayah penelitian adalah 55.598 ha. Evaluasi kesesuaian lahan fisik menggunakan metode faktor pembatas, sedangkan evaluasi kesesuaian secara ekonomi mengacu pada prosedur Land Evaluation Computer System (LECS) yang di modifikasi FAO (1983) dan Rossiter (1988) dalam Djaenudin (2008). Hasil penelitian menunjukkan bahwa wilayah penelitian terdiri dari 26 satuan lahan yang berasal dari berbagai bahan induk. Tanah yang terbentuk beragam, meliputi ordo Alfisol, Entisol, Inceptisol, Ultisol dan Vertisol. Kelas kesesuaian lahan untuk komoditas yang dievaluasi didominasi oleh kelas lahan sesuai marginal (S3) dengan faktor pembatas utama adalah t (temperatur), r (media perakaran), f (retensi hara) dan n (hara tersedia). Perbaikan kualitas lahan dapat meningkatkan kelas kesesuaian aktual, seperti pemupukan yang cukup dan seimbang, pemberian bahan organik dan pengapuran, serta tindakan koservasi. Nilai GM dan B/C rasio untuk tanaman padi sawah, kedelai dan kacang hijau bervariasi. Nilai B/C rasio pada kelas kesesuaian S1, S2 dan S3 untuk tanaman padi sawah dan kacang hijau bernilai > 1, sedangkan untuk tanaman kedelai hanya pada kelas kesesuaian S1 dan S2 yang bernilai > 1. Nilai B/C rasio tersebut menunjukkan bahwa tanaman padi sawah dan kacang hijau layak untuk dikembangkan, sedangkan untuk tanaman kedelai kurang layak untuk dikembangkan.
Keyword: Land characteristics,, physical land evaluation, economical land Evaluation

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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