A study was conducted to assess the level of Cr, Pb, Cd, Ni, Zn, Cu, Fe and Mn contamination in the sediment samples of the Buriganga river, at the Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh. Total 14 sediment samples were collected from different areas of upstream of the Buriganga river. The mean concentrations of total Cr, Pb, Cd, Ni, Fe, Cu, Zn and Mn in the sediment samples were 173.4, 31.4, 1.5, 153.3, 481.8, 344.2, 12989 and 4036 µg g -1 , respectively. The range of pH and EC of sediment were 5.87-8.21 and 230-707 µS cm -1 , respectively. The mean value of organic matter in sediment samples was 13.4%. Heavy metal concentrations in sediment were compared with geochemical background and standard values, previous report on the Buriganga river and other rivers in Bangladesh. The average concentration of Cr, Pb and Ni in sediments of the Buriganga river is almost twice of the geochemical background i.e. average worldwide shale standard and continental upper crust value, Cd and Zn is about five times and Cu content is about ten times higher than the geochemical background values. Average concentration of Cr, Cu and Ni exceeded the severe effect level (SEL) values, where as Pb, Cd and Zn exceeded toxicity reference values (TRV). However, the concentration of heavy metal in the sediment samples of the Buriganga river for the year 2009 of the same river reported by corresponding author was relatively higher than this study average. The average Enrichment factors (EFc) for Zn, Cu, Mn and Cd reflects extremely contaminated pollution level which implies that these metals originated from point source of pollution and very severely enriched in river sediments. The pollution load index (PLI) of sediments of the studied region varied from 1.61-7.51. The geoaccumulation index (I geo ) for Cu of five locations was greater than 3.0, which exhibited strongly polluted sediment quality. The I geo for Mn in 11 locations and Zn in 12 sites were greater than 1.0, indicated moderately polluted sediment quality. Heavy metal pollution intensity in the Buriganga river water and sediments signaled alarming condition for city dwellers and aquatic ecosystem of the river. Sustainable steps and continuous monitoring on pollution prevention and cleanup operation is suggested to minimize pollution.

The amounts and forms of zinc in twenty surface soils from Canterbury and Southland, New Zealand were determined using a sequential fractionation scheme. Total soil zinc concentrations ranged from 38.1 mg·kg -1 to 113.8 mg·kg -1 . Although the proportions of zinc found in individual fractions varied between soils, on average approximately 3% occurred as exchangeable zinc, 5% as organic-bound zinc, 9%, 18%, 24% was associated with manganese, amorphous iron and crystalline iron oxides, respectively, and 40% was in the residual fraction. In a group of soils formed in greywacke alluvium or loess, exchangeable zinc was inversely related to soil pH. Within the same group of soils, those of similar age with greater concentrations of total and organicbound zinc were present in imperfectly-and poorly-drained soils compared with well-drained soils. Zinc extracted from the soils with a range of reagents used to assess 'plant available' zinc was correlated strongly with the concentrations of zinc present in the exchangeable and organic-bound zinc fractions.

A study was undertaken to evaluate the status of organic matter, mineral nutrients and heavy metals content in seven differentsoils from fourteen selected regions of Bangladesh. The location were BAU farm, Sutiakhali, Ishardi, Lalpur, Dumuria,Kotalipara, Asasuni, Chorfasion, Kaligonj, Botiaghata, Madhupur, Tangail sadar, Chakaria and Moheskhali. Forty two surfacesoils (0-15 cm depth) were collected from 14 regions (3 samples from each region) of Bangladesh during November-December,2009. The results obtained from this study showed that the organic matter of these soils very low to very high (0.65% inMadhupur to 28.24% in Dumuria) and the total N content of soil followed the same trend of organic matter ranging 0.056 to1.638% in Madhupur and Dumuria region, respectively. The available P and S in the top of soils ranged from 3.77 ?g g-1 in Moheskhali to 17.28 ?g g-1 in BAU farm and 13.40 ?g g-1 in Madhupur to 420.32 ?g g-1 in Moheskhali, respectively. In the contextof micro nutrients, the maximum available Zn, Cu, Fe and Mn were found 6.43 ?g g-1 in Dumuria, 8.06 ?g g-1 in Chakaria, 346.12?g g-1 in Madhupur and 83.5 ?g g-1 in Madhupur, respectively. whereas the lowest amount of these micronutrients were found 1.22?g g-1 in Botiaghata, 0.2 ?g g-1 in Dumuria, 7.62 ?g g-1 in Ishardi and 2.39 ?g g-1 in Lalpur, respectively. Possible contamination ofthe studied soils by heavy metals was not significantly observed. The OM, total N and other nutrients were found to be the dominantfactors influencing not only the availability of macro and micro nutrients and heavy metals but also the quality of soil.DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14570 J. Environ. Sci. & Natural Resources, 5(2): 01-09 2012

An experiment was carried out at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh in transplant Aman season 2008 to find out the effect of urea super granules (USG), prilled urea (PU) and poultry manure (PM) on the yield and yield attributes of transplant Aman rice varieties. Two transplant Aman rice varieties viz. BRRI dhan41 and BRRI dhan46 and ten levels of integrated nutrient management encompassing USG, PU and PM were tested following randomized complete block design with three replications. It was observed that variety BRRI dhan41 gave higher grain yield than BRRI dhan46. For fertilizer effect, the highest grain yield (5.17 t ha -1 ) was obtained from full dose of USG (1.8g) and other inorganic fertilizers, which was similar to that obtained from full dose of USG (1.8g) + PM at 2.5 t ha -1 followed by full dose of PU + PM at 2.5 t ha -1 . The lowest grain yield was obtained in the control treatment. In case of interactions, the highest grain yield was obtained in BRRI dhan41×1.8g USG and other inorganic fertilizers which was similar to that of the same dose of USG with PM at 2.5 t ha -1 and the lowest yield was obtained in the control treatment. It was assessed that a considerable portion (31.25%) of PU nitrogen could be saved by using USG (1.8g) together with other inorganic fertilizers or with PM at 2.5 t ha -1 .

Gibberellic acid (GA 3 ) was sprayed with eleven doses viz. 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 ppm at the primordia initiation stage to evaluate its effect on the growth and yield performance of Oyster Mushroom. At 10 ppm level GA 3 gave the highest economic yield and dry weight. Application of GA 3 increased the fresh economic yields to about 30% and 34%, while 80% and 115% dry weights increase occurred compared to the control at first and second harvests, respectively. GA 3 showed a positive effect on number of effective fruiting body, stalk length, pileus diameter, biological yield, economic yield and dry economic yield. The result suggested that GA 3 at 10 ppm/packet would be the best possible concentration for production of Oyster Mushroom.