Effect of organic and inorganic sources of nutrients on soil microbial activity and soil organic carbon build-up under rice in west coast of India

The effect of medium-term (5 years) application of organic and inorganic sources of nutrients (as mineral or inorganic fertilizers) on soil organic carbon (SOC), SOC stock, carbon (C) build-up rate, microbial and enzyme activities in flooded rice soils was tested in west coast of India. Compared to the application of vermicompost, glyricidia (Glyricidia maculate) (fresh) and eupatorium (Chromolaena adenophorum) (fresh) and dhaincha (Sesbania rostrata) (fresh), the application of farmyard manure (FYM) and combined application of paddy straw (dry) and water hyacinth (PsWh) (fresh) improved the SOC content significantly (p < 0.05). The lowest (p < 0.05) SOC content (0.81%) was observed in untreated control. The highest (p < 0.05) SOC stock (23.7 Mg C ha^?1) was observed in FYM-treated plots followed by recommended dose of mineral fertilizer (RDF) (23.2 Mg C ha^?1) and it was lowest (16.5 Mg C ha^?1) in untreated control. Soil microbial biomass carbon (C_mb) (246 µg g^?1 soil) and C_mb/SOC (1.92%) were highest (p < 0.05) in FYM-treated plot. The highest (p < 0.05) value of metabolic quotient (qCO₂) was recorded under RDF (19.7 µg CO₂-C g^?1 C_mb h^?1) and untreated control (19.6 µg CO₂-C g^?1 C_mb h^?1). Application of organic and inorganic sources of nutrients impacted soil enzyme activities significantly (p < 0.05) with FYM causing highest dehydrogenase (20.5 µg TPF g^?1 day^?1), phosphatase (659 µg PNP g^?1 h^?1) and urease (0.29 µg urea g^?1 h^?1) activities. Application of organic source of nutrients especially FYM improved the microbial and enzyme activities in flooded and transplanted rice soils. Although the grain yield was higher with the application of RDF, but the use of FYM as an organic agricultural practice is more useful when efforts are intended to conserve more SOC and improved microbial activity.     

Weed Management in Rice-Wheat Cropping System through Remote Sensing： A Review

The productivity of the flee-wheat rotation of the Indo-Gangetie Plains is critical to India＇s food security. Severe weed competition resulting from the change in morphological characteristics of the modem high yielding varieties （HYV） led to intensive use of herbicides for weed control. Continuous and indiscriminate use of herbicides led to pollution as well as build up of resistant biotypes. This necessitates the need based use of herbicides. Identification of predominant weeds in rice-wheat cropping system through remote sensing and Geographic Information System （GIS） would help in reducing the load of herbicide on agro-eco system by reducing spray volume, application time and non-target spraying. This will help in developing site-specific weed management technique by geating only those areas with herbicide where weed densities exceed the economic threshold and may reduce application rate of herbicides in patches where weed densities are low. This paper reviews the literature on role of remote sensing for weed management not just to review their empirical findings, but to evaluate the role they have played and have the potential to play-in actual for weed management in flee-wheat cropping system （food bowl of India）.     

Variation in the nutritional quality of rice straw and grain in response to different nitrogen levels

Abstract

Nitrogen (N) applied through urea is essential for rice crops and usually it is the most yield-limiting nutrient in irrigated rice production around the world. A field experiment was conducted to evaluate the effect of nitrogen levels (0, 90,120, and 150?kg?ha^?1) on the nutritional quality of straw and grain of rice varieties, PR 111, PR 122, and Pusa 44. In rice straw, significant interaction between nitrogen levels and all proximate components was observed. Increase in nitrogen level increased the crude protein by 69.23% (dry matter basis) whereas the neutral detergent fiber, acid detergent fiber, and cellulose content decreased by 7.82%, 11.18%, and 14.16%, respectively. In rice grain, crude protein content, starch content, and gel consistency were positively related to increase in nitrogen levels. Therefore, increase in nitrogen fertilization led to improved nutritive quality of both straw and grain for use as feed resource and human consumption, respectively.     

Antibacterial Activity of 2-(2′,4′-Dibromophenoxy)-4,6-dibromophenol from Dysidea granulosa

2-(2′,4′-Dibromophenoxy)-4,6-dibromophenol isolated from the marine sponge Dysidea granulosa (Bergquist) collected off the coast of Lakshadweep islands, Indian Ocean, exhibited potent and broad spectrum in-vitro antibacterial activity, especially against methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), vancomycin resistant Enterococci (VRE), vancomycin sensitive Enterococci (VSE) and Bacillus spp. Minimal inhibitory concentration (MIC) was evaluated against 57 clinical and standard strains of Gram positive and Gram negative bacteria. The observed MIC range was 0.117–2.5 μg/mL against all the Gram positive bacteria and 0.5–2 μg/mL against Gram negative bacteria. The in-vitro antibacterial activity observed was better than that of the standard antibiotic linezolid, a marketed anti-MRSA drug. The results establish 2-(2′,4′-dibromophenoxy)-4,6-dibromophenol, as a potential lead molecule for anti-MRSA and anti-VRE drug development.     

Immunogenicity of Major Cell Surface Protein(s) of Brucella melitensis Rev 1

Brucella melitensis Rev 1 organisms were salt-extracted and the cell surface proteins (BCSPs) were found to be mainly 39-42 kDa (group 2 porin proteins) in addition to 31.6, 32.5, 58.5 and 14.7 kDa proteins. DEAE-Sephadex anion-exchange column chromatography of BCSPs yielded fraction 1, which contained one major protein (39.8-42.0 kDa) and a minor protein (31.6 kDa). All these proteins were found to be immunogenic by Western blotting. Fraction 1 along with monophosphoryl lipid A and trehalose dicorynomycolate adjuvants as well as BCSPs alone induced significant (p < or = 0.05) protection in BALB/c mice. Both these immunizing agents produced almost equivalent protection to live B. melitensis Rev 1 vaccine at 15 and 30 days post challenge. Lymphocyte stimulation test as well as delayed-type hypersensitivity reaction revealed that both these preparations induced cell-mediated immune response. These preparations also induced humoral immune response as indicated by indirect ELISA. Neither of the immune responses was significantly less (p < or = 0.05) than that with live B. melitensis Rev 1 vaccine, except that their duration was short.     

Antimicrobial ability and growth promoting effects of feed supplemented with probiotic bacterium isolated from gut microlfora of Cirrhinus mrigala

The present studies were conducted to isolate, select, identify and characterize gut bacteria as antimicrobial and growth promoting agent for the feed of economical y important ifsh Cirrhinus mrigala. ...     

Effect of organic amendments on uptake of selenium and biochemical grain composition of wheat and rape grown on seleniferous soils in northwestern India

Crops grown in seleniferous soil may accumulate selenium (Se) to levels considered highly toxic for animal and human consumption. Furthermore, higher Se content in plant tissues leads to considerable deterioration in product quality. Application of organic amendments plays an important role in improving soil physical, chemical, and biological conditions and influencing nutrient availability. A field trial was conducted to evaluate the effect of organic amendments, namely poultry manure (PM), sugar cane press mud (SCPM), and farmyard manure (FYM), on Se uptake and grain quality of wheat and oilseed rape grown on a seleniferous soil in Punjab, India. Selenium accumulation by wheat and oilseed rape grains decreased significantly (75%–95%) with the application of PM and SCPM, while FYM application resulted in a significant decrease (23%) only in case of wheat grains. The amount of Se associated with seed proteins varied in proportion to its uptake under different treatments. Quality of wheat grains improved considerably with respect to total soluble sugars, reducing sugars, starch, lipids, and sulfur concentrations only after application of SCPM and PM. Treating a Se‐contaminated soil with organic amendments significantly increased the oil concentration and changed the proportion of various fatty acids in rape grains. It is concluded that applying organic amendments to Se‐contaminated soils can alleviate the deleterious effects of Se and restore the nutritional quality of grains.