Physico-chemical properties, carbon dioxide emissions and carbon stock in peat soil used for turmeric cultivation at Kuala Langat Selatan, Selangor, Malaysia

Measurement of carbon dioxide emissions in peat soil was done in a turmeric cultivation area on August 2009 and January 2010 at Kampung Tumbuk Darat, Kuala Langat Selatan, Selangor. The objective of this research was to determine the quantity of CO2 emissions from peat soil as well as the carbon stock that is stored in the peat soil. Other parameters that were investigated included soil pH, soil temperature, soil bulk density, soil organic carbon, soil fresh water content, organic matter, humic acid and fulvic acid content. A total of 30 carbon dioxide emission sampling points in rectangular grid arrangement was prepared in a survey plot of 1 hectare. The survey plot was further divided into sub-plots of size 20 m x 25 m. Soil samples were randomly taken at the depth of 0-15 cm to 50-65 cm using an auger. Sampling of CO2 emissions was done using the static alkali absorption method (Kirita Method). The organic carbon content was determined using the Walkley-Black method, while the humic and fulvic acid content was determined using the basic molecule isolation method. Other soil properties were determined using standard methods of determination. The surface temperature of peat soil was between 28oC and 30oC. The bulk density of the area was as low as 0.20 g cm-3. On the other hand, the soil fresh water content, soil organic matter, and peat soil humic acid was very high. The minimum quantity of CO2 emissions in the peat soil on August 2009 and January 2010 was 40.92±21.62 t CO2 ha-1 yr -1 (467.10±246.86 mg CO2 m-2 hr-1) and 41.51±13.41 t CO2 ha-1 yr -1 (473.86±153.12 mg CO2 m-2 hr -1), respectively. Carbon stock for the month of August 2009 and January 2010, respectively was 297.70 t ha-1 and 456.60 t ha-1. T test showed that there were significant (p<0.05) differences in many of the soil parameters such as the pH, water content and organic carbon. Correlation analysis showed that CO2 is influenced by the organic matter, water content and temperature

Assesment of heavy metals in a Malaysian diet

Pencemaran logam berat sering kali menjadi isu kerana kaitannya dengan masalah kesihatan. Pencemaran logam berat menunjukkan peningkatan di muka bumi ini akibat daripada aktiviti manusia. Makanan merupakan tapak jalan utama kemasukan logam berat kepada manusia. Pengumpulan yang tinggi di dalam makanan boleh mendatangkan kemudaratan kepada manusia. Pengambilan seharian logam plumbum dan kadmium oleh penduduk Kota Kinabalu ditentukan dengan menggunakan kaedah ‘market basket study’. Kaedah ini digunakan untuk menentukan paras logam di dalam makanan individu yang dibeli secara rawak daripada pasar utama yang dipilih iaitu Pasar Besar Kota Kinabalu, Inanam,Menggatal, Telipok dan Tuaran serta di pasaraya. Hasil kajian ke atas empat kumpulan makanan menunjukkan paras kandungan logam adalah dibawah paras yang dibenarkan oleh Akta Makanan Malaysia, 1983. Melalui kaedah ini, jumlah logam kadmium, plumbum dan nikel yang diambil oleh penduduk Kota Kinabalu dalam sehari ialah 3.72 mg/hari, 19.66 mg/hari dan 15.83 mg/hari

Pengambilan logam berat oleh pokok daun kari (Murraya koeniggi) dalam tanih ultrabes dari Felda Rokan Barat, Kuala Pilah, Negeri Sembilan, Malaysia

Kajian ini telah dijalankan di kawasan tanih ultrabes di Felda Rokan Barat, Kuala Pilah, Negeri Sembilan. Sebanyak lima belas sampel tumbuhan dan substratnya telah diambil dari kawasan kajian dengan kaedah berkelompok. Tujuan kajian ini adalah untuk menentukan kandungan logam berat Fe, Ni, Cr, Mn, Co, Zn, Cu, Cd dan Pb di dalam tanih dan bahagian akar, batang dan daun tumbuhan. Koefisien penyerapan biologi (BAC) ditentukan secara perkiraan. Kandungan logam berat di dalam tumbuhan diekstrak secara penghadaman basah manakala kandungan di dalam tanih diekstrak dengan kaedah pengekstrakan berjujukan. Kandungan logam berat di dalam larutan ekstrak tanih dan tumbuhan ditentukan menggunakan spektrofotometer penyerapan atom kaedah nyalaan (FAAS). Hasil kajian menunjukkan kepekatan logam berat paling tinggi dalam substrat pokok daun kari Murraya koenigi adalah Fe, diikuti oleh Mn, Cr, Co, Ni, Zn, Cu, Cd dan Pb dengan purata kepekatan masing-masing sebanyak 1699.64 mg/kg, 532.59 mg/kg, 212.43 mg/kg, 195.02 mg/kg, 174.97 mg/kg, 48.11 mg/kg, 43.86 mg/kg, 3.65 mg/kg dan 0.48 mg/kg. Kepekatan logam berat tersedia bagi Mn dan Pb adalah lebih tinggi berbanding logam berat tersedia yang lain berdasarkan peratus. Kandungan Fe dan Mn adalah tinggi di dalam semua bahagian tumbuhan. Walau bagaimanapun, berdasarkan nilai purata kumulatif BAC, hanya logam Pb menunjukkan nilai penimbunan yang agak tinggi dalam tumbuhan. Kajian ini menunjukkan pokok daun kari (Murraya koenigi) bukan tumbuhan penumpuk logam berat berdasarkan kepada nilai BACnya yang rendah

Influence of amang (Tin Tailing) on geotechnical properties of clay soil (Pengaruh amang timah terhadap sifat geoteknik tanih lempung)

Amang or tin tailing is commonly found in the vicinity of disused mining area and responsible in downgrading the water quality, landscape and mechanical behaviour of soils. It was generated from extraction process of separating valuable metal from particular ore. This paper presents the geotechnical characteristics of amang-contaminated clay soil. The geotechnical properties of uncontaminated soils were studied in order to compare to that of amangcontaminated soils. The base soil used in this study represents completely weathered horizon of metasedimentary rock. Meanwhile, tin tailing sample was taken from the disused mine at Sungai Lembing, Pahang. The geotechnical characterisations of base soil and contaminated soils were determined based on consistency index, compaction behaviour, hydraulic conductivity and undrained shear strength (UU tests). Contaminated soil samples were prepared by adding 5, 10 and 20% of tailing, based on dry weigh of the studied base soil. The results from the particle size distribution analysis showed that residual soil from metasedimentary rock comprised 42.6% clay, 32.2% silt and 25.2% sand whilst tailing was dominated by 98% of sand fraction. XRD analysis indicated the presence of quartz, kaolinite and muscovite minerals in the studied soil. The specific gravity of soil used is 2.67 and the pH is 3.88. Tailing found to have higher specific gravity of 3.37. The consistency index of contaminated soils showed that liquid limit, wL and plastic limit, wP decreased with the increase in the percentage of tailing added to the soil samples. The value of maximum dry density, ρ dry max increased while optimum moisture content decreased due to the increase in tailing content in soil sample. The permeability of contaminated soil also increased with the increase in tailing contents ranged from 19.8 cm/hr to 23.8 cm/hr. The undrained shear strength, Cu, of contaminated soil decreased from 646 kPa (5% of tailing) to 312 kPa (20% of tailing) suggesting that the presence of tailing has influenced the geotechnical properties on the studied soil

Assessment of CHADFDM

Aquifer natural recharge estimations are a prerequisite for understanding hydrologic systems and sustainable water resources management. As meteorological data series collection is difficult in arid and semiarid areas, satellite products have recently become an alternative for water resources studies. A daily groundwater recharge estimation in the NW part of the Lake Chad Basin, using a soil–plant-atmosphere model (VisualBALAN), from ground- and satellite-based meteorological input dataset for non-irrigated and irrigated land and for the 2005–2014 period is presented. Average annual values were 284 mm and 30°C for precipitation and temperature in ground-based gauge stations. For the satellite-model-based Lake Chad Basin Flood and Drought Monitor System platform (CHADFDM), average annual precipitation and temperature were 417 mm and 29°C, respectively. Uncertainties derived from satellite data measurement could account for the rainfall difference. The estimated mean annual aquifer recharge was always higher from satellite- than ground-based data, with differences up to 46% for dryland and 23% in irrigated areas. Recharge response to rainfall events was very variable and results were very sensitive to: wilting point, field capacity and curve number for runoff estimation. Obtained results provide plausible recharge values beyond the uncertainty related to data input and modelling approach. This work prevents on the important deviations in recharge estimation from weighted-ensemble satellite-based data, informing in decision making to both stakeholders and policy makers.ISSN:0885-6087ISSN:1099-108

Spatial-temporal evaluation of different reference evapotranspiration methods based on the climate forecast system reanalysis data

Evapotranspiration is a major component of the interaction between land-surface processes and the atmosphere. Climate Forecast System Reanalysis (CFSR) data offer a promising database for overcoming the limitations in availability and reliability of climatological data and, hence, for understanding the evapotranspiration process. Using these data on grid-by-grid daily, seasonal and yearly scales, the present study attempts to advance the spatio-temporal evaluation of two radiation-based and three temperature-based methods for estimating potential evapotranspiration (PET) against estimates of grass reference evapotranspiration (ETo) by FAO Penman-Monteith method (FAO-PM). The analysis was performed for the period 1979-2013, considering the second largest (79 000 km(2)) river system in Ethiopia, that is, Omo-Gibe basin, which accommodates national parks and vast hydropower, cultivation and afforestation developments and discharges its flow to Lake Turkana in Kenya. Despite the large regional variations in climate and elevation, the results in overall emphasize the outperformance of the simple temperature method, viz. Hargreaves-Samani method, in capturing both the annual and seasonal FAO-PM estimates. Calibration of the Hargreaves-Samani equation is, however, a requisite for spectacular improvement of its performance. Accordingly, new coefficients of the equation are proposed. The annual trends in the basin's ETo increased with rising temperature and decreasing relative humidity, wind speed, and solar radiation, but with decreasing (increasing) rainfall in the upper region (the middle and lower regions). It is deduced that trends in simple methods do not necessarily reflect the true trends in ETo. Annual ETo decreases with increasing elevation and annual rainfall. The present findings are discussed in the context of a worldwide literature, thereby improving the understanding of the best performing PET methods in similar data-scarce national or transboundary rivers basin in Ethiopia, the region or worldwide. The wider implications regarding water loss from reservoirs and the rain-fed food and sugar production in the basin under study are also highlighted