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To study the compositional trends of rare earth elements (REEs: La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Lu), Th and U in soil samples collected from a site for a potential coal based power plant as well as to conduct a preliminary assessment of environmental impact of the proposed power plant in terms of REEs, Th and U, we have analyzed nine soil samples by instrumental neutron activation analysis. Evaluation of data quality by repeated analysis of IAEA-Soil-7 and IAEA-SL-1 ensures a proper data base-line for the REEs, Th and U abundances of the sampling site. Chondrite-normalized abundance patterns demonstrate the heavy REEs–light rare earth elements and Th–U fractionations in our sample suite along with significant negative Eu anomaly. Thorium/U ratio in our study area ranges from 4.55 to 6.07 which is higher than that of upper continental crust. Preliminary assessment of environmental impact of the proposed power plant is evaluated by taking NIST-SRM-1633b (coal-fly-ash) as contaminant as coal-fly-ash will be the major byproduct of the power plant. Previous literature studies and our prevailing data invoke that proposed power plant will have no severe impact on soil originated biota and on human health in terms of REEs, Th and U abundances. However, the long term effect of excessive REEs, Th and U as well as the other elemental abundances originating from coal-fly-ash should also be taken into an account.

Plants grown in highly weathered or highly alkaline calcareous soils often experience phosphorus (P) stress but never a P-free environment. Thus, applications of mineral P fertilizers are often required to achieve maximum yield, but recovery of applied P fertilizers is notoriously low. Phosphorus deprivation elicits a complex array of morphological, physiological, and biochemical adaptations among plant species and genotypes to enhance P acquisition and utilization efficiency. Ten Brassica cultivars were grown hydroponically to investigate their relative efficiency to utilize deficiently (20-mM) and adequately (200-mM) supplied P, using Johnson's modified solution. Cultivars differed significantly (P , 0.001) in biomass accumulation. Orthophosphate concentration and uptake in shoot and root, absolute and relative growth rate, and P-utilization efficiency (PUE) were also significantly different among various Brassica cultivars. Root-shoot ratio and specific absorption rate were substantially increased in plants subjected to low P supply. Shoot and root dry-matter yield as well as total biomass production correlated significantly (P , 0.01) with their total P uptake and PUE. Cultivars, which were efficient in P utilization, were also efficient accumulators of biomass under adequate as well as deficient levels of P supply. As part of the study, kinetic parameters of P uptake were evaluated for six contrasting Brassica cultivars in PUE, grown in nutrient solution. The kinetic parameters related to P influx were maximal transport rate (Vmax), the Michaelis-Menten constant (Km), and the external concentration when net uptake is zero (Cmin). Lower Km and Cmin values were indicative of P-uptake ability of the cultivars, evidencing their adaptability to P-stress conditions. In another experiment, six cultivars were exposed to no P nutrition for 27 days after initial feeding on optimum nutrition for 14 days. All the cultivars retranslocated P from aboveground parts to their roots during growth in P-free conditions, the magnitude of which was variable in different cultivars. Phosphorus concentration at 41 days after transplanting was higher in developing leaves than developed leaves. Translocation of absorbed P from metabolically inactive sites to active sites in plants growing under P-stress conditions may have helped the tolerant cultivars to establish a better rooting system, which provided basis for tolerance against P-deficiency stress and increased PUE.

A field experiment was conducted for the reclamation of a Badarkhali hot spot of acid sulfate soil manipulated by flash leaching followed by basic slag (BS) at 10 t ha−1 (BS10) and 20 t ha−1 (BS20) and aggregate sizes (A) of soil less than 20 mm (A20) and less than 30 mm (A30) treatments under two different techniques (Tech 1: pyrite layer at top, jarosite layer at middle and topsoil at the bottom of the ridge; Tech 2: topsoil at top, pyrite layer at middle and jarosite layer at the bottom of the ridge). Responses to two cultivars of rice (Pizam [local cultivar] and BR 14 [high yielding cultivar]) with the treatments were evaluated. The initial soil had a very low pH(H2O) 4.0 and a high electrical conductivity (EC) of 1.4 m S−1, and the pyrite content was 68 g kg−1. The exchangeable Mg content of the soil was approximately twice that of Ca and the Al content was at a highly toxic level. The average soil data of all the treatments, except for the control plots (where no amendment was applied), after harvesting of rice increased by 1.1 units for soil pH and 17–524% for the contents of N, P, Ca and Mg, while the concentrations of Fe, Al, Na, Cl− and SO42– decreased by 30–94% compared with the initial soil. The maximum growth and yield of rice grains (4.4 t ha−1) were obtained by the Pizam compared with the BR 14 (4.0 t ha−1) in the A20BS20 treatment in the ridges of Tech 2. The lowest grain yields of 0.02 (BR 14) and 0.07 t ha−1 (Pizam) were recorded for the control plots. The other treatments also resulted in significantly (P ≤ 0.05) improved performance on rice production. The highest N, P, K, Ca and Mg contents in the shoots of BR 14 and Pizam rice were obtained under the A20BS20 treatment followed by the A20BS10 ≥ A30BS20 treatments. Application of A20BS20 under Tech 2 is the most appropriate reclamation option and the local Pizam is the most suitable rice for this soil.