Nitrous oxide emission from different fertilizers and its mitigation by nitrification inhibitors in irrigated rice     

U. Kumar  M. C. Jain  H. Pathak  S. Kumar  D. Majumdar 《Biology and Fertility of Soils》2000,32(6):474-478

 N₂O emissions from a transplanted irrigated rice grown on a Typic Ustochrept soil at New Delhi, India, were studied to evaluate the effect of N fertilizers, i.e. urea and (NH₄)₂SO₄, alone and in combination with the nitrification inhibitors dicyandiamide (DCD) and thiosulphate. The addition of urea and (NH₄)₂SO₄ increased N₂O emissions considerably when compared to no fertilizer N application (control). N₂O measurement in the field was done by a closed-chamber method for a period of 98 days. The application of urea with DCD and thiosulphate reduced N₂O fluxes considerably. The highest total N₂O-N emission (235 g N₂O-N ha^–1) was from the (NH₄)₂SO₄ treatment, which was significantly higher than the total N₂O-N emission from the urea treatment (160 g N₂O-N ha^–1). DCD reduced N₂O-N emissions by 11% and 26% when applied with urea and(NH₄)₂SO₄, respectively, whereas thiosulphate in combination with urea reduced N₂O-N emissions by 9%. Total N₂O-N emissions were found to range from 0.08% to 0.14% of applied N. N₂O emissions were low during submergence and increased substantially during drainage of standing water. Received: 20 October 1999  相似文献   

Prevalence of rabies antibodies in street and household dogs in Chandigarh,India     

Mini P. Singh  Kapil Goyal  Manasi Majumdar  Radha Kanta Ratho 《Tropical animal health and production》2011,43(1):111-114

The present study reports the first survey for the detection of antirabies antibodies in street and household dogs in India. We aimed to check the efficacy of control programs for the disease in the Union territory of Chandigarh. The serum samples were collected from 100 street and 50 household dogs and tested for the presence of antirabies antibodies by ELISA. As per WHO criteria, a titre of >0.5 IU/ml of antirabies antibody in serum samples was taken as the protective level. Protective antirabies antibody titre was found only in 1% of the street dogs and 16% of the pet dogs. The awareness among the pet dog owners about the antirabies vaccination schedule was low as 18% did not know the vaccination status of the dog and 66% had got the initial immunization done with only three doses and annual boosters were not given. A National Rabies Elimination Program needs to be launched as a collaborative venture by both medical and veterinary practitioners to curb this deadly disease. Also periodic surveys to test the status of antirabies IgG among dogs need to be carried out to ascertain the attainment of WHO protective levels  相似文献   

Interaction of nanoparticles with edible plants and their possible implications in the food chain   总被引：5，自引：0，他引：5  

Rico CM  Majumdar S  Duarte-Gardea M  Peralta-Videa JR  Gardea-Torresdey JL 《Journal of agricultural and food chemistry》2011,59(8):3485-3498

The uptake, bioaccumulation, biotransformation, and risks of nanomaterials (NMs) for food crops are still not well understood. Very few NMs and plant species have been studied, mainly at the very early growth stages of the plants. Most of the studies, except one with multiwalled carbon nanotubes performed on the model plant Arabidopsis thaliana and another with ZnO nanoparticles (NPs) on ryegrass, reported the effect of NMs on seed germination or 15-day-old seedlings. Very few references describe the biotransformation of NMs in food crops, and the possible transmission of the NMs to the next generation of plants exposed to NMs is unknown. The possible biomagnification of NPs in the food chain is also unknown.  相似文献   

Potential use of karanjin (3-methoxy furano-2′,3′,7,8-flavone) as a nitrification inhibitor in different soil types     

Deepanjan Majumdar Dr  Bhavesh Pandya  Anu Arora  Soni Dhara 《Archives of Agronomy and Soil Science》2013,59(4-5):455-465

Karanjin, a furanoflavonoid (3-methoxy furano –?2 ′ , 3 ′ , 7, 8-flavone), is obtained from the seeds of karanja tree (Pongamia glabra Vent.), which is reported to have nitrification inhibitory properties but has been tested in few soil types. Efficiency of karanjin as a nitrification inhibitor in seven different soils of India was tested in a laboratory incubation study. The soils (800?g) were adjusted to field capacity moisture content, fertilized with urea and urea combined with karanjin at a rate of 20% of applied urea-N (100?mg?kg^???1 soil) and incubated at 35°C for a period of 7 weeks, during which urea [CO(NH₂)₂], ammonium (NH₄ ^?+?), nitrite (NO₂ ^???) and nitrate (NO₃ ^???) content in the soils was measured periodically and nitrification inhibition at different stages was calculated. Urea hydrolysis was almost complete within 72?h of application in all the soils and was not affected by karanjin. Karanjin had conserved ammonium in all the soils at all stages and nitrate formation was effectively minimized. Nitrite in soils was short-lived and low. Nitrification inhibition by karanjin remained high for a period of approximately 6 weeks, decreased with time and ranged from 9?–?76% for all the soils. The study shows that this plant product can be an effective nitrification inhibitor in several types of soil.  相似文献   

Crop yield and soil nitrogen dynamics in an intermittently flooded rice field affected by nitrification inhibitors     

Deepanjan Majumdar 《Archives of Agronomy and Soil Science》2013,59(6):645-653

A field experiment was conducted to study yield and soil N dynamics in an irrigated, intermittently submerged rice field at New Delhi, India, where chemically synthesized as well as neem derived urea coating nitrification inhibitors with prilled urea were applied. Rice (var. IR-32) was grown on a Typic Ustochrept alluvial soil. No nitrogen (control), prilled urea alone, prilled urea mixed with dicyandiamide (DCD), neem (powdered Azadirachta indica Juss. seeds) coated urea and Nimin (commercial derivative of neem) coated urea were tested for their efficacy in regulating yield and conservation of N. None of the inhibitors could increase biomass or grain yield over urea. But all the inhibitors were able to conserve soil ammonium and DCD was the most efficient nitrification inhibitor followed by Nimin coated urea. N-uptake, recovery, physiological and agronomic efficiencies were highest in urea treated plots. The performances of all the inhibitors were against the popular trend where crop yield and N-uptake were enhanced by their application. But, more studies are required on the performance of these inhibitors in rice fields to come to a stronger conclusion.  相似文献   

Genetic diversity in the Indian population of Penaeus monodon (Fabricius, 1798) as revealed by mtDNA sequence analysis     

Niraj Kumar  Wazir S Lakra  Kshitish C Majumdar  Mukunda Goswami  & Kondadhasula Ravinder 《Aquaculture Research》2007,38(8):862-869

Genetic diversity in the Indian population of the tiger shrimp Penaeus monodon was determined by using partial sequence data of the mitochondrial DNA (mtDNA) control region (D‐loop) and the 16S rRNA gene. Eight populations from different geographical locations (Mumbai, Kochi, Mangalore, Kakinada, Gopalpur, Chilika, Paradeep and Andaman) were collected and analysed. The amplified polymerase chain reaction products of size 577 bp for the control region and 472 bp for 16S rRNA were sequenced in both directions and data were analysed through clustal , arlequin , mega and phylip . A significant genetic structure was found among the Indian populations. The mtDNA control region proved to be a powerful marker in comparison with 16S rRNA for population studies of this species. The east coast population was more genetically diverse than the west coast. The Andaman population was found to be the most diverse among all the populations. The populations on the west coast were found to be genetically more structured and differentiated than the populations on the east coast. The results revealed a high level of genetic diversity and also distinct population structuring of P. monodon, suggesting great possibilities of genetic improvement for growth and other economic traits.  相似文献   

Tilapia stock identification using electrophoretic markers   总被引：8，自引：0，他引：8  

B.J. McAndrew  K.C. Majumdar 《Aquaculture (Amsterdam, Netherlands)》1983,30(1-4):249-261

With the difficulties in the identification of the many tilapia species, a reliable method independent of morphological characteristics was needed to define the nature of the cultured stocks throughout the world. Starch gel electrophoresis of various body tissues and the resolution of protein loci using specific histochemical techniques has shown that a large amount of co-dominant interspecific variation exists which may be used to identify unequivocally the nine different species studied. The technique and relevant buffer systems and stains are described together with an account of the enzymes observed and their interpretation. The results are expressed as relative mobilities of the observed isozyme bands, allowing direct comparison between all the species studied. The potential of the technique is discussed regarding its possibilities in tilapia culture and in the general genetic improvement of stocks.  相似文献   

Changes of woody species diversity,horizontal and vertical distribution of stems across interior to outside within a primate rich habitat of Northeast India     

Koushik Majumdar  Bal Krishan Choudhary  Badal Kumar Datta 《林业研究》2016,27(4):787-798

The interior forest of protected area(PA)recover quickly in terms of greater diversity and structural complexity than peripheral and outsides, which may be due to high plant-frugivore interactions in the interior forest than the disturbed outsides. To describe the structural and functional differences in tree communities from interior to outside forests with in small PA, we quantitatively analyzed the vegetation of Trishna Wildlife Sanctuary, a rich primate habitat of Northeast India. Vegetation was sampled at C10 cm girth at breast height by 10 m 9 500 m sized20 line transects(10 ha) laid in the interior(N = 7),peripheral(N = 7) and outside(N = 6) zones of this sanctuary. All transects were ordinated by Principal Component Analysis based on correlation between diversity and existing disturbance indices. We found significant differences(P \ 0.05) in taxonomic richness and diversity indices between the habitat. Van diagram confirmed greater unique species richness in the interior zone(64) than peripheral(28) and outside(6) zones. Overall density(ha-1) did not differed across the zones, but basal area(m2ha-1) was significantly(P \ 0.01) high in peripheral zone. Vertical distribution of stem density was linearly declined across zones(r2adj[ 0.70; P \ 0.01) with increase in the canopy height. Horizontal distribution of adult stems showed significant inverse quadratic relationship(r2adj[ 0.80; P \ 0.001), which suggests very low density of canopy forming voluminous trees in the interior zone.Immediate protection, restoration and management of interior regions are required to preserve local plant genetic diversity and also to maintain suitable habitat for threatened wildlife.  相似文献   

Influence of Previous Washing Process and Storage Time on Chemical Composition and Sensory Quality of Thai Pangas (Pangasius sutchi) Minced Muscle During Frozen Storage     

Ranendra K. Majumdar  Sujata Debbarma  Prasenjit Pal 《Journal Of Aquatic Food Product Technology》2013,22(3):288-298

ABSTRACT

This work focuses on the effect of a washing process followed by frozen storage (3 months; ?18°C) on the quality of minced pangas muscle. A previous washing step has led to a positive effect on fish quality according to marked decreases in expressible moisture (28%), volatile amines (25.7%), free fatty acids (24.5%), and thiobarbituric acid reactive substances (29%). However, such indexes showed quality loss throughout the frozen storage. Amongst quality indexes, special attention should be given to the expressible moisture value and the water holding capacity, as being closely related to the gel-forming ability in order to obtain surimi-type commercial products.  相似文献   

Characterizing the tensile properties of spun yarns using bivariate normal distribution     

Anindya Ghosh  Abhijit Majumdar 《Fibers and Polymers》2010,11(4):642-647

The tensile properties of spun yarns decisively influence its performance in various mechanical processing stages. This study is primarily aimed at simultaneous analysis of two tensile properties of spun yarns namely tenacity and breaking strain, which play crucial role in determining the frequency of warping breaks. The threshold values of yarn tenacity and breaking strain required for 20’s Ne carded cotton yarn to sustain the imposed stresses and strains during warping process have been determined using a bivariate normal distribution model. This study opens up the possibility of minimizing end breakage rate in various manufacturing processes of textile industry by engineering of spun yarns devoid of potential weak spots which are responsible for breaks.  相似文献