Judul: Evaluation of Soil Fertility in Some Farmlands in the North and South of Brebes District, Central Java
Abstrak: Brebes merupakan salah satu kabupaten dengan komoditas pertanian yang beragam. Budidaya pertanian yang diterapkan sebagian besar merupakan pertanian intensif yang menggunakan pupuk sintetik anorganik yang digunakan secara berlebihan dan terus-menerus. Perbedaan lokasi dan ketinggian memiliki pengaruh dalam tingkat kesuburan tanah. Evaluasi kesuburan tanah sangat penting untuk dilakukan guna menilai, memantau, dan mengatasi kendala hara tanah. Penelitian ini bertujuan untuk mengevaluasi kesuburan tanah di 39 lokasi yang terdiri dari tanah di Kabupaten Brebes bagian utara dan selatan. Penelitian ini dilakukan melalui beberapa tahapan yaitu pengambilan contoh tanah dan analisis sifat kimia tanah, penilaian sifat kimia tanah, analisis perbandingan kation berdasarkan Base Cation Saturation Ratio (BCSR), evaluasi kesuburan tanah, pembuatan peta sebaran hara N, P, K, dan status kesuburan tanah, serta analisis data. Hasil menunjukkan bahwa rata-rata status kesuburan tanah di Brebes bagian utara sedang, dengan C-organik sebagai faktor pembatas. Brebes bagian selatan memiliki rata-rata status kesuburan tanah tinggi. Berdasarkan uji t bahwa, pH, C-Organik, N-total, P2O5 HCl 25%, K2O HCl 25%, KTK, KB, Ca dd, dan Mg-dd tanah di bagian utara berbeda sangat nyata dan nyata pada parameter Na-dd dengan tanah di bagian selatan, kecuali P2O5 dan K-dd. Meskipun demikian, P2O5 dan K-dd tanah di bagian utara relatif lebih tinggi dibandingkan di bagian selatan. Pengelolaan tanah yang intensif oleh petani menyebabkan ketidakseimbangan hara kation basa tanah di bagian utara dan selatan. Rasio kation basa yang didapatkan menunjukan tingkat kation yang jauh dari proporsi ideal. Ketidakseimbangan hara teridentifikasi melalui tingginya konsentrasi Ca dan Mg, yang dapat mempengaruhi pergerakan kation K, yang berpotensi menghambat penyerapan K oleh tanaman., Brebes are districts with a diverse range of agricultural commodities. Agricultural cultivation is mostly intensive farming using synthetic inorganic fertilizers used excessively and continuously. Differences in location and altitude influenced the soil fertility. Soil fertility evaluation is essential to assess, monitor, and overcome soil nutrient constraints. This study aimed to evaluate soil fertility in 39 locations consisting of soils in northern and southern Brebes Districts. This research was conducted through several stages, namely soil sampling and analysis of soil chemical properties; assessment of soil chemical properties; analysis of cation ratio based on Base Cation Saturation Ratio (BCSR); soil fertility evaluation; mapping of N, P, and K nutrient distribution and soil fertility status; and data analysis. The results showed that the average soil fertility status of northern Brebes was moderate, with organic C as the limiting factor. Southern Brebes has a high average soil fertility status. Based on the t-test pH, Organic C, total N, P2O5 HCl 25%, K2O HCl 25%, CEC, Base Saturation, exchangeable Ca, and exchangeable Mg of soils in the northern part differed significantly and significantly on exchangeable Na parameters to soils in the southern part, except for P2O5 and Exchangeable K. Intensive soil management by farmers causes an imbalance in the soil base cation nutrients in the north and south regions. The base cation ratios obtained showed cation levels far from ideal proportions. Nutrient imbalance was identified through high concentrations of Ca and Mg, which can affect the movement of K cations and potentially inhibit K uptake by plants.
Keyword: BCSR, Brebes, Kesuburan Tanah, Pertanian, Klasterisasi Lokasi

Judul: Spatial Distribution of Soil Nutrients in Sawah Baru Agriculture Fields, Dramaga District, Bogor Regency
Abstrak: Tanaman padi merupakan komoditas pangan utama yang dikonsumsi masyarakat Indonesia. Kabupaten Bogor salah satu wilayah yang berkontribusi signifikan dalam memenuhi kebutuhan komoditas padi di Jawa Barat dan sekitarnya. Akan tetapi, masih terdapat permasalahan pada penurunan produksi, produktivitas dan luas panen lahan padi sawah. Pemanfaatan metode interpolasi Ordinary Kriging bagi lahan sawah di Indonesia masih sangat minim, terutama informasi status hara pada lahan pertanian di Kabupaten Bogor. Penelitian ini bertujuan untuk menganalisis, memetakan, dan membandingkan pola spasial parameter kesuburan tanah (pH H2O, C-organik, dan status hara tanah) pada tanaman padi menggunakan metode Kriging di Lahan Sawah Baru Dramaga, Kabupaten Bogor. Hasil penelitian menunjukkan keragaman semivariogram dari setiap parameter kesuburan tanah (pH H2O, C-organik, N-total, P-tersedia, P-total, K-total, yang dapat ditukar (Ca-dd, Mg-dd, K-dd, Na), KTK dan KB) yang dikuantifikasi dari nugget effect, sill, dan range dalam semivariogram. Distribusi spasial beberapa parameter kesuburan tanah di wilayah penelitian bervariasi dengan rentang dari sangat rendah sampai dengan sangat tinggi dengan akurasi berbeda. Pemetaan dengan metode interpolasi Ordinary Kriging melalui semivariogram spherical juga menunjukkan tingkat akurasi berbeda. Parameter pH H2O, K-total, Ca-dd, dan Mg-dd mempunyai akurasi yang lebih kuat serta parameter P-total dan Kdd mempunyai akurasi yang moderat dibandingkan parameter lain. Sedangkan, parameter C-organik, P-tersedia, N-total, Na-dd, KTK, dan KB mempunyai akurasi yang lebih lemah menunjukkan parameter tersebut kurang akurat dalam menggambarkan kondisi aktual wilayah penelitian., Rice is a main food commodity consumed by Indonesians. Kabupaten Bogor is one of the regions that significantly contributes to West Java’s demand. However, problems in production decrease, productivity, and total harvested paddy field have widely been acknowledged, whilst land resource datasets have largely been insufficient. This research assessed ordinary kriging interpolation, which has been limitedly investigated on the retrievals of soil nutrients. This research goal was to analyze, to map, and to compare spatial pattern of soil fertility parameters (pH H2O, soil organic carbon (OC), and soil nutrient status). Experiment was conducted in Sawah Baru agriculture fields, Kecamatan Dramaga, Kabupaten Bogor. Results showed a variety of semivariogram, observed from soil fertility parameters (i.e., pH H2O, soil organic carbon (OC), Total-N, P-Available, Total-P, Total-K, Exchangeable Ca, Mg, K, Na, cation exchange capacity (CEC), and base saturation), with respect of nugget effects, sills, and ranges in respective semivariograms. Spatial distribution of soil fertility parameters broadly varied with divergent accuracies. Modeling using spherical-type semivariogram also indicated unassociated levels of accuracy. pH H2O, Total-K, Exchangeable Ca, and Exchangeable Mg were parameters with strong accuracy levels, while Total-P and Exchangeable K displayed moderate accuracy compared to other parameters. Meanwhile, soil organic carbon (OC), P-Available, Exchangeable Na, CEC and base saturation indicated a lower accuracy, suggesting that those parameters warrant an in-depth analysis in the future.
Keyword: Ordinary Kriging, kesuburan, semivariogram, fertility

Judul: The addition of a noun word graph dictionary module in bogordelftconstruct
Abstrak: Knowledge Graph is a new method in Natural Language Processing that is used to describe human language and displaying it into a graph form. BogorDelftConStruct is a tool to analyze Indonesian text, developed by Deni Romadoni (2009). The tool has limited feature, opening many opportunities to add some other features. The goal of this research is to develop a noun word graph dictionary module and add it in BogorDelftConStruct. The patterns of the noun word-graph are based the research of Saleh (2009). In this research, of the 20 patterns in Saleh (2009) only 13 patterns are used, since some of word graph patterns which have the same affix and also have the different meaning. As many as 144 nouns were used in scenario testing, with 1 error was generated (99,33% accuracy).
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