Assessment of the phytoavailability of Cu and Ni using various extraction procedures

The phytoavailability of copper (Cu) and nickel (Ni) in soils from Bangladesh was assessed. The uptake by Ipomoea aquatica and Oryza sativa L. was measured and a range of extractants tested on soils and plant tissue samples. Extractants tested were distilled water, 1 M NH4Cl, 0.01 M CaCl2, 0.005 M diethylenetriamine penta‐acetic acid (DTPA), 0.1 M ethylenediamine tetraacetic acid (EDTA), 0.1 M HCl and 1 M HCl. The extractability of the metals varied depending on the metal species, the crop and the extractant used. The best extractant was 1 M HCl, which extracted the highest amount of the heavy metals and correlated most strongly with their plant uptake measures. The use of 1 M HCl is, therefore, recommended for first‐level screening of soils contaminated with heavy metals if only one extractant is to be used. Sequential extraction showed that Cu was associated mostly with the 0.005 M DTPA and 0.1 M EDTA extractable fractions, while Ni was associated with the 0.1 M HCl and 1 M HCl fractions in most cases. The fractions of metals extracted using the sequential extraction procedure varied compared to single extractions for all soil types.&#x0D; Dhaka Univ. J. Biol. Sci. 24(1): 1-16, 2015 (January)</jats:p

Effects of old jute seeds on soil fertility and jute production

A field experiment was conducted to evaluate the effects of old jute seed powder (≥3 years old) on soil fertility and jute production using the high yielding variety of jute (Corchorus olitorius L.) O-9897 as the test plant. Six treatments of jute seed powder (JSP) and recommended dose of chemical fertilizers (RDF) with three replications were as T1: Control, T2: JSP 5 t/ha + ¼ RDF, T3: JSP 5 t/ha + ½ RDF, T4: JSP 5 t/ha + ¾ RDF, T5: RDF, and T6: JSP 5 t/ha. The growth and yield of jute were found to be the maximum for the treatment T4 (JSP+ ¾ RDF), where the plant height, base diameter, fiber yield and stick weight were increased 147, 85, 177, and 125%, respectively over the control. The highest contents of organic carbon, nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium in soil were also observed for the treatment T4. The sole application of jute seed powder increased the growth and yield of jute as well as the contents of nutrients in soil compared to the control; however, inputs of the jute seed powder in combination with the chemical fertilizers showed better results in improving soil fertility and jute production.&#x0D; J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 33-40</jats:p

Effects of Sewage Sludge at different pH Levels on Ipomoea Aquatica

An experiment was conducted to study the effects of sewage sludge on the response of Ipomoea aquatica to plant nutrients and heavy metals  in soil at different soil pH. An incubation study was done for the selection of four individual pH levels, viz., 4.7, 5.7, 6.6 and 7.8 to be  used for the plant culture experiment. Yield of Ipomoea aquatica and concentration and uptake of N, P, K, Ca, Mg, Cd, Cu, Fe, Mn and Zn  in the plant were evaluated. Application of sewage sludge in soil increased the concentration and uptake of the elements in Ipomoea. Slightly  acidic to slightly alkaline pH was found to be better for amendment of soil with sewage sludgeDOI: http://dx.doi.org/10.3329/bjsir.v47i1.10721 Bangladesh J. Sci. Ind. Res. 47(1), 47-54, 2012</jats:p

Alleviation of arsenic accumulation in rice by applying silicon-rich rice husk residues in Bangladesh soil

While the accumulation of arsenic in rice (Oryza sativa L.) has been highlighted as a major concern in Bangladesh, sustainable measures are critically needed to reduce the uptake of arsenic by rice plants. In the present study, a pot-experiment was conducted using a Boro rice variety (BRRI dhan-29) in two geomorphologically different soils from Holocene floodplains and Pleistocene terraces, in which silicon-rich fresh rice husk (FRH) and rice husk ash (RHA) were applied, as silicon fertilisers, in the soils at the rate of 1% (w/w) of rice residue:soil.In the Holocene floodplain soils, the application of FRH was found to decrease arsenic in grain, husk and straw by 42, 56 and 51%, respectively, whereas the soil incorporation of RHA decreased arsenic in grain, husk and straw by 26, 37.5 and 36%, respectively. In the Pleistocene terrace soils, the application of FRH reduced the grain, husk and straw arsenic by 38, 38 and 44%, respectively, whereas the RHA decreased the grain, husk and straw arsenic by 26, 30 and 29%, respectively. Fresh rice husk was found to be more effective in alleviating arsenic accumulation in rice than RHA. In both the Holocene floodplain and Pleistocene terrace soils, the grain concentrations of calcium, phosphorus, silicon, and zinc were found to be increased with the decrease of arsenic in the grain due to the use of FRH and RHA. The present study suggests that silicon-rich rice husk residue scan be used as silicon fertilisers to reduce arsenic accumulation in rice in Bangladesh. Bangladesh J. Sci. Ind. Res.56(3), 195-206, 2021</jats:p