Scenario of heavy metal contamination in agricultural soil and its management

Soil is a complex structure and contains mainly five major components i.e. mineral matter, water, air, organic matter and living organisms. The quantity of these components in the soil does not remain the same but varies with the locality. Soil possesses not only a nucleus position for existence of living being but also ensures their future existence. Therefore, it is essential to make an adequate land management to maintain the quality of soil in both rural and urban soil. The presence of different kinds of heavy metals such as Cd, Cu, Mn, Bi and Zn etc. in trace or in minimum level is a natural phenomenon but their enhanced level is an indicator of the degree of pollution load in that specific area. The precise knowledge of these kinds of heavy metals, their forms and their dependence on soil provides a genuine base for soil management. The heavy metals have potent cumulative properties and toxicity due to which they have a potential hazardous effect not only on crop plants but also on human health. The metal contaminants can be reduced by immobilization of contaminants using macrophytes and also by using genetically engineered microorganisms

Organic matter depositional microenvironment in deltaic channel deposits of Mahanadi river, Andhra Pradesh

Quantitative and qualitative variations in microscopic plant organic matter assemblages and its preservation state in deltaic channel deposits of Mahanadi River was correlated with the depositional environment in the ecosystem in order to prepare a modern analogue for use in palaeoenvironment studies. For this, palynological and palynofacies study was carried out in 57 surface sediment samples from Birupa river System, Kathjodi-Debi River system and Kuakhai River System constituting Upper, Middle and Lower Deltaic part of Mahanadi river. Theapex of the delta shows dominance of Spirogyra algae indicating high nutrient, low energy shallow ecosystem during most of the year and recharged only during monsoons. The depositional environment is anoxic to dysoxic in the central and south-eastern part of the Middle Deltaic Plain (MDP) and Lower Deltaic Plain (LDP) indicated by high percentage of nearby palynomorphs, Particulate Organic Matter (POM) and algal or fungal spores. The northern part of the delta show high POM preservation only in the estuarine area in LDP but high Amorphous Organic Matter (MOA) in MDP. The sediment here is deposited under dysoxic to oxic fluvial conditions. Thus, the monsoon intensity, direction of fluvial discharge, and the landward extent of sea water incursion through river mouths inducing bottom water salinity play an important role in defining the magnitude of POM and its preservation in the shallow Mahanadi deltaic ecosystem

Integrated nutrient management to enhance biochemical resistance in rice against sheath blight

Application of potassium either as recommended, deficient or excess dose, enhanced the level of phenolic contents, increased incubation period and thereby decreased the sheath blight severity. Application of nitrogen and phosphorous, either as recommended, deficient or excess dose resulted in reduction of phenolic content, shorter incubation period and thereby increasing the sheath blight severity. Recommended sulphur application, enhanced the phenolic contents, increased incubation period and thereby decreased the sheath blight severity. Recommended zinc application resulted in enhancement of phenolic contents, longer incubation period and thereby decreasing the sheath blight severity. Excess application of zinc, reduced the phenolic contents and incubation period but the severity of sheath blight was also lowered down. Recommended iron application (1.5 kg./ha) enhanced the phenolic contents and incubation period with a decreased level of sheath blight severity. Deficient and excess doses of iron also showed the similar trend of effect on phenolics, incubation period and sheath blight severity

Impact of climate change on biodiversity of India with special reference to Himalayan region-An overview

India possesses a distinct identity, not only because of its geography, history and culture, but also because of the great diversity of its natural ecosystems. The panorama of Indian biological diversity is much wider, as it comes under the twelve mega biodiverse (Hot-spot) centers of the world. It contains a great wealth of biological diversity in its forests, its wetlands and in its marine areas which are distributed all over the country. This richness is shown in absolute numbers of species and the proportion they represent of the world total. The great Himalayan region has peculiar identity in the perspective of its unique biogeography. It supports a large number of glaciers, lakes, rivers, flora and fauna due to its variable climate. It has a profound effect on the climate of the subcontinent. But due to anthropogenic activities the global climate has changed since last few decades. The climate of the subcontinent has also adversely affected the biological resources of the country along with that of the Himalayan region. The present paper discusses the various causes responsible for melting and shrinkage of glaciers, decreasing water flow in the major rivers, increasing pressure of extinction of the ecological wealth of the country. It also talks about the control measures and various management steps which can be taken, with special reference to the Himalayan region

Preliminary phytochemical studies for the quantification of secondary metabolites of medicinal importance in the plant, Acalypha fruticosa Forssk

The medicinal plant, Acalypha fruticosa Forssk for the treatment of dyspepsia, stomachache, fever, jaundice, skin diseases and even as an antidote is generally distributed in different environments of tropical region in Coimbatore district of Tamil Nadu. However, its occurrence is more common in lower hills of Western Ghats and other habitats in this region where the soil is stony with low moisture. So far, there was no study on the influence of habitat conditions on the change in the content of secondary metabolites of medicinal importance in this plant. Hence to know the changes in the content of such secondary metabolites in the leaves of A. fruticosa, the present study was undertaken in three different habitats. Thin layer chromatography revealed the presence of phytochemical compounds viz., alkaloids, flavonoids and saponins in the leaves of all the three populations. Further the content of all these compounds are found to be higher in the population of dry habitats

Best fitting probability distributions for annual maximum discharge data of the river Kopili, Assam

In this study our main objective is to determine the best fitting probability distribution for annual maximum flood discharge data of river Kopili, Assam. Various probability distributions i.e. Gumbel (G), generalized extreme value (GEV), normal (N), log-normal (LN3), generalized logistic (GLO), generalized pareto (GPA) and Pearson type-III (PE3) have been used for our study. The L-moments methods have been used for estimating the parameters of all the distributions. The root mean square error (RMSE), model efficiency and D-index (fit in the top six values) together with L-moment ratio diagram is used for goodness of fit measure. It has been observed that Generalized Pareto is the best fitting probability distribution for annual maximum discharge data of river Kopili

Alterations in carbohydrate metabolism under cryptorchid condition in albino rats

Bilateral cryptorchidism was induced surgically in adult wistar strain albino rats and the carbohydrate metabolic pathway has been studied in testis, and sex accessory organs of both control and cryptorchid animals by estimating the marker enzymes and the substrates of the metabolism. In cryptorchid animal tissues, accumulation of lactic acid and glycogen was observed with inhibited phosphorylase activity in comparison to the controls. The reproductive tissues like testis, epididymis, prostate gland and seminal vesicles had shown remarkable elevation in the glycogen content, which can be attributed to decreased phosphorylase activity. In view of androgen dependent nature of phosphorylase its inhibition can be correlated to decreased testosterone circulation in the body. Consequently the free glucose content of the tissues was markedly decreased suggesting a decrease in the mobilization of the carbohydrates into energy metabolism. All the reproductive tissues had shown significant accumulation of lactic acid with inhibited oxidative enzyme activities. Thus the reproductive tissue oxidative metabolism had been suppressed during cryptorchidism leading to a shift towards glycolysis and creating a situation of functional suppression

Impact of changing ecophysiological conditions in blood urea levels of freshwater fish Wallago attu

Definite cyclic variations were observed in blood urea levels of freshwater catfish Wallago attu. The maximal mean blood urea level (8.44±1.96 mg/100 ml) was noted in the month of June while minimal level in December, revealing a difference of 65.87% between the two levels. Seasonal alterations observed here in W. altu were correlated with ecophysiological factors like temperature, food availability, body metabolism, breeding cycle and hormonal changes which have been essentially found to be involved in fish life