No abstract

This study examined the concentration of heavy metals in 13 fish species. The results indicated that shellfish species (clams) have the highest metal concentrations, followed by demersal and pelagic fishes. The mean concentration of metals in clams are Zn 88.74 ± 11.98 µg/g, Cu 4.96 ± 1.06 µg/g, Pb 1.22 ± 0.19 µg/g, Cd 0.34 ± 0.04 µg/g dry wt. basis, whereas the same measure in fish tissues was 58.04 ± 18.51, 2.47 ± 1.21, 0.58 ± 0.27 and 0.17 ± 0.08 µg/g dry wt. basis. The concentrations of heavy metals in clams and fish tissues were still lower than the maximum allowable concentrations as suggested by the Malaysian Food Act (1983) and are considered safe for local human consumption.

No abstract

Longsor dapat dipicu oleh karateristik tanah yang terbentuk pada suatu wilayah yang dipengaruhi oleh ukuran fraksi tanah, terutama fraksi tanah yang berukuran lebih halus, yaitu fraksi tanah dari mineral liat. Stabililitas wilayah sub DAS Jeneberang pasca kejadian runtuhnya kaldera Gunung Bawakaraeng, menyebabkan gangguan berupa longsoran disekitar wilayah sub DAS lainnya. Penelitian ini bertujuan untuk mengetahui karakteristik ukuran butir dan mineral liat tanah pada kejadian longsor  di sub DAS hulu Jeneberang. Penelitian ini menggunakan metode deskriptif kuantitatif dengan mengidentifikasi ukuran butir menggunakan ayakan ASTM 48 dan mineral liat tanah menggunakan FTIR. Titik longsor (TL) ditentukan dari kejadian longsor yang terjadi dan titik pembanding (TPB) ditentukan dari topografi dan bahan induk yang sama dengan titik longsor. Topografi pada daerah penelitian berombak hingga sangat curam dengan rata-rata curah hujan delapan tahun terakhir 3484 mm/tahun. Hasil analisis Ukuran butiran pada semua titik longsor dan titik pembanding didominasi ukuran 0,5 mm dengan bentuk butiran subrounded pada TL1, TL3, TL5, TL6, TL7, TL8, TL 10, TPB3, TPB4 dan subangular pada TL2, TL4, TL9, TPB1, TPB2. Dari hasil analisis mineral liat bahwa mineral liat dominan pada TL1, TL2, TL3, TL10, TPB1, TPB2  adalah kaolinit. TL6, TL5 adalah haloisit. TL8, TL4 adalah montmorilonit. TL9, TL7, TPB3 adalah klorit dan TPB4 adalah nakrit. Longsor yng terjadi dipicu oleh mineral liat tersedia yaitu kaolinit, haloisit, montmorilonit, dan klorit, sementara ukuran butir tanah tidak memberikan banyak pengaruh pada kejadian longsor.Kata kunci: Sub DAS Jeneberang, Longsor, Ukuran Butir, Mineral Liat Tanah

Background and Objective: External factors such as lithology, climate, slopes, land cover and soil have been carried out to provide solutions in anticipating and responding to land degradation, but disasters still occur. So it is imperative to see the impact of internal soil factors on some potential land use land cover in this area to answer and anticipate the effects of climate change in predicting the susceptibility of the soil to disasters. This study aims to study the soil micromorphology of some land cover in the landslide susceptibility area of the Kelara Subwatershed in Rumbia District, Jeneponto Regency of South Sulawesi. Materials and Methods: The study is descriptive exploratory through field surveys and supported by data from laboratory analysis. Laboratory analyses include soil texture analysis, particle density, bulk density, porosity, permeability and thin section analysis for micromorphological observations in soil. Results: The clay fraction content increased >25% in all land cover due to increased rainfall since 2010, which triggered an increase in soil mineral weathering activity. Land use for mixed plants showed a significant increase in clay >30% and plane voids. Permeability in the mixed plant reached 0.42 cm hrG 1 with category very slow has significantly different from another land cover and induced landslide. Conclusion: Increasing clay and decreasing soil permeability trigger the formation of plane voids which cause the soil to undergo a micro shrinking and slipping process and internal micro-shifts. It is the key to improving soil susceptibility to landslides in mixed plant land use in the sloping area.

No abstract

Intensive cropping in the tropical region always becomes one of important driving forces of soil degradation. The primary aim of this study is to analyze the states and the dynamics of soil physicochemical properties to evaluate soil degradation in the tropical region a high rainfall on agricultural areas in South Sulawesi. A number of soil characteristics were analyzed for physical and chemical properties, and clay minerals with X-ray diffractometer. The degree of soil degradation is determined using Wischmeier and Smith equation. This study reveals that mean annual precipitation in 1979-2016 ranged from 1853.15 to 2981.30 mm/year. For land used for paddy field, palm oil, cacao and coffee plantation, the texture dominated with silt loam-clay loam, cation exchange capacity was 18.63-26.32 cmol+ kg-1, 0.98-2.91% of C-organic, 32-55% of base saturation, 0.1-3.5 cm h-1 of permeability, soil clay minerals were montmorillonite-kaolinite-halloysite, and the index erodibility was 0.3-0.5. Land used for mixed plants and shrubs, the texture dominated with silt loam-sandy clay loam, cation exchange capacity was 18.63-27.12 cmol+ kg-1, 1.09-2.89% of C-organic, 32-55% of base saturation, 0.2-4.9 cm/h of permeability, soil clay minerals were kaolinite-halloysite, and index erodibility was 0.1-0.3. Land use for cultivated in the high intensity of rainfall has changed the physicochemical properties of soils, but cultivated in monoculture has at some degree increased soil erodibility.

Clove is a superior crop and the main source of income for farmers in South Halmahera, especially in Bacan island. There is an increase in the clove planting area since 2013. However, clove productivity in 2017 decreased by 32% from 2013 to 2017. The factors that influence clove production are the environment and the soil condition. Clove plants to be able to grow and produce require specific growing environmental requirements. Environmental factors that influence clove plants include climate, height and type of soil. This study aims to analyze the suitability of land for clove plants on Bacan Island. Methods for collecting land resource data include primary data surveys and secondary data collection. The land suitability evaluation was carried out according to the limiting approach. The results of land suitability analysis at the subclass level in several districts in the Bacan Island for clove plants showed that the suitability of land suitability varied (S1, S2, S3, and N) between districts with limiting factors are erosion hazard and the effective depth roots.