Bakteri endofitik penambat nitrogen (N2) yang bersimbiosis dengan tanaman padi dapat digunakan sebagai pupuk hayati karena dapat memberikan nitrogen yang ditambatnya langsung pada tanaman. Penelitian pot ini bertujuan untuk mendapatkan konsentrasi dan teknik aplikasi pupuk hayati cair bakteri endofitik penambat N2 yang tepat dalam meningkatkan populasi bakteri endofitik penambat N2 dan  hasil tanaman padi sawah.  Percobaan dirancang dalam Rancangan Acak Kelompok yang menguji faktor konsentrasi pupuk hayati (25, 50, 75 dan 100 ml l-1 pupuk hayati) dan metode aplikasi pupuk (Perendaman, Penyemprotan dan kombinasinya) . Hasil percobaan memperlihatkan adanya peningkatan populasi bakteri endofitik penambat N2 di daun, batang, dan akar setelah aplikasi pupuk hayati baik melalui teknik perendaman, penyemprotan maupun kombinasinya. Aplikasi  100 ml l-1 pupuk hayati melalui semua teknik menghasilkan gabah kering panen 85,89 g tanaman-1, lebih besar  7,79 %  daripada penggunaan 50 ml l-1 pupuk hayati.

The efforts to utilize the agricultural land need a proper understanding of the soil characteristics. The soil characteristics themselves are influenced by the factors that regulate and control the soil forming and pedogenesis processes. The main soil forming factors in this study was the different ages and composition of parent materials from the eruption of Mt. Tangkuban Parahu in West Java. This research was done to comprehend the pedogenesis and to figure out the soil classifications that developed in two geological formations (Qyd and Qvu) and two ages of eruption (Holocene and Pleistocene) of Mt. Tangkuban Parahu. The study was conducted in Ciater, Subang Regency and Jatinangor, Sumedang Regency in West Java Province. The study consisted of four stages: preparation, field survey and soil sampling, laboratory analysis and presenting the report. The results showed that Pedon of Jatinangor consisted of three different stratifications of ages. The clay mineralogical composition was dominated by kaolinite, whereas mineralogical composition of the sandy fractions (heavy fractions) was augite-hypersthene. Pedon of Ciater also consists of three different stratifications of age. The clay mineralogical composition was dominated by allophane, while mineralogical compositions of the sandy fractions (heavy fractions) were green amphibole-hypersthene in the overlying horizons and amphibole-augite in the underlying horizons. The stage of soil formation on both pedon were cambic or viril. The soil classification according to Soil Taxonomy were Acrudoxic Durudands, medial over loamy-skeletal, isohyperthermic in Ciater Pedon and Fluventic Eutrudepts, fine, kaolinitic, isohyperthermic in Jatinangor Pedon.Key words: slow sand filter, activated carbon, silica sand, sand, gravel, zeolite

The Ciletuh Geopark area is an international geopark area recognized by UNESCO. As the area is undergoing development, it certainly raises some land and environmental problems, especially in agriculture. This study is intended to determine soil characteristics and collect field data and other supporting data from soil and social, physical factors, so that these data can be useful in the development of the Ciletuh Geopark Area, especially the development of agricultural areas. The purposes of this study were 1) To obtain comprehensive field data so that the soil characteristics of the Ciletuh Geopark area can be known, 2) How to spread the soil fertility status in Geopark Ciletuh Area, Ciemas District, Sukabumi Regency. This research was expected to provide an overview of soil fertility based on chemical and physical properties of the soil and can provide detailed soil resource information for the development of science to support research activities, and it was expected to provide preliminary information or primary data on soil fertility as part of the development of Ciletuh Geopark. The location of the study was conducted in the Ciletuh Geopark Area, Ciemas District, Sukabumi Regency, West Java Province. The study was conducted with qualitative, descriptive, and comparative methods and survey methods. The sampling of land was carried out in each unit of land, which is determined by transect based on the results of environmental observations so that it is sufficiently representative to represent the land in the area. Analysis of physics properties, soil chemistry, was carried out in the Laboratory of Plant Chemistry and Nutrition, Universitas Padjadjaran. Mapping analysis was carried out at the Land Evaluation Laboratory of the Department of Soil Science, Universitas Padjadjaran. The results showed that soil fertility status at the study site was moderate to low criteria with limiting factors P (phosphorus) and carbon organic soil. Land management that needs to be done was by adding organic materials and phosphorus fertilization regularly so that soil fertility can be good maintained and can be sustainable.

Effect of slope gradient and its position to plow depth layer, organic matter, Al and Fe contentsThis research was done to know the influence of slope gradient and its position to plow depth layer, organic matter, Al and Fe contents. This research was carried out January-March 2011. The research used survey method with descriptive comparative analysis with free physiographic approach based on land cover. Sampling technique was used a purposive stratified sampling. Soil sampel took from three slope gradients: 8-15%, 16-25% and 26-40% with three position of crest, middle and lower positions. The result showed that the gradient of slope and its position have influenced plow layer depth and content of iron but organic material and Al were not influenced. The highest of plow layer depth and content of iron were occured at 8-15%, while the highest of content of Al and iron were occured at 16-25 %. Based on slope position, the thick of plow layer, the content of organic matter, Fe wereoccured highest in the lower position and Al was occured in the middle position.Keywords: Slope, plow depth layer, organic matter, Al, FeABSTRAKPenelitian ini dilakukan untuk mengetahui adanya pengaruh dari kelas kemiringan dan posisi lereng terhadap ketebalan lapisan olah, bahan organik, Al dan Fe. Penelitian dilakukan pada bulan Januari-Maret 2011 dengan menggunakan metode survai dan analisis deskriptif komparatif melalui pendekatan fisiografis secara bebas berdasarkan penampakan fisiografis lahan. Teknik sampling berdasarkan metode sampel pertimbangan dalam stratifikasi. Contoh tanah diambil dari tiga kelas kemiringan lereng : 8-15%, 16-25% dan 26-40% dengan tiga posisi lereng yaitu posisi atas, posisi tengah dan posisi bawah. Hasil penelitian menunjukkan bahwa kemiringan dan posisi lereng berpengaruh terhadap ketebalan lapisan olah dan kandungan Fe sedangkan terhadap bahan organik dan kandungan Al tidak berpengaruh. Ketebalan lapisan olah dan bahan organik tertinggi dijumpai pada kemiringan lereng 8-15% sedangkan kandungan Al dan Fe tertinggi yaitu pada kemiringan lereng 16-25%. Berdasarkan posisi lerengnya, ketebalan lapisan olah, bahan organik, kandungan Fe tertinggi dijumpai pada posisi lereng bawah sedangkan kandungan Al pada posisi lereng tengah.Kata Kunci: Lereng, Ketebalan lapisan olah, Bahan organik, Al, Fe

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