Current Science

Biswajit Ghosh ¹, Namita Chakma ²

Affiliations
1 Khorad Amena High School, Satgachia, Barddhaman 713 422, IN
2 Department of Geography, The University of Burdwan, Barddhaman 713 104, IN

Abstract

Rice is an important cereal crop of West Bengal and in many of the Indian states. There is a compelling need to increase rice productivity vertically in West Bengal due to less availability of land and greater dependency of the population on the productivity of the land. For this reason, the economic and ecological potentiality of the system of rice intensification (SRI) has been evaluated by several researchers. In the present study, Monteswar and Memari-II C. D. blocks of Barddhaman district, West Bengal have been selected to analyse the impacts of SRI on economic and ecological aspects of rice-growing. Results show that benefit-cost (B : C) ratio in SRI practice is significantly higher than the conventional method of rice cultivation. Under SRI B : C ratio varies from 5.06 : 1 to 3 : 1, but in the conventional method it varies from 2.18 : 1 to 1.78 : 1. Therefore, SRI farmers are experiencing multiple benefits in terms of both economics and ecology.

Keywords

Agro-Ecology, Benefit–Cost Ratio, Economic and Ecological Potentiality, System of Rice Intensification.

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Thungyani N. Ovung ¹, Jyotisankar Ray ¹, Xueming Teng ², Biswajit Ghosh ¹, Madhuparna Paul ¹, Proloy Ganguly ¹, Saradee Sengupta ¹, Supriyo Das ¹

Affiliations
1 Department of Geology, Calcutta University, 35 B.C. Road, Kolkata 700 019, IN
2 School of Earth Sciences and Resources, China University of Geosciences Beijing, 29 Xueyuan Road, Beijing 100083, CN

Abstract

Mineralogical studies on the mantle and crustal sections of the Manipur Ophiolite Belt (MOB) lead to important findings pertaining to its genesis and controlling tectonic milieu. The wide compositional gap in the Cr# and Mg# content of spinel in the mantle peridotites of MOB implies upper mantle melting in two different tectonic settings. The tectonic discrimination diagrams based on spinel chemistry indicate a midoceanic ridge (MOR) origin for the high-Al spinel peridotites and a supra-subduction zone origin for the high-Cr spinel peridotites. The pyroxenite mantle dyke, ultramafic cumulate and pillow-basalt record temperature in the range of 600-1030°C, 600-800°C and 700-1005°C respectively. Plotting of clinopyroxene composition of pillow-basalt in the TiO₂-Na₂O-SiO₂/100 (wt%) tectonic discrimination diagram, implies a subduction-related origin of the basalts. Experimental studies on the serpentine stability indicate that it was dominantly affected by high temperature-low deformation setting.

Keywords

Mineralogical Study, Ophiolite Belt, Pyroxenite Mantle Dyke, Pyroxene Thermometry.

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Arindam Guha ¹, Biswajit Ghosh ², Sukanya Chaudhury ², Komal Rani ¹, K. Vinod Kumar ¹

Affiliations
1 Geosciences Group, National Remote Sensing Centre, Indian Space Research Organization, Balanagar, Hyderabad 500 625, IN
2 Department of Geology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019, IN

Abstract

We have collected, processed and analysed the reflectance spectra of representative chromitite samples of spot type, clot type and disseminated type textural variants to understand the diagnostic spectral features of each of these samples. We have found that the reflectance spectrum of each textural variant is distinct from the spectra of other variants despite having few common absorption features. Spectral features of chromitite samples are governed by the spectra of two dominant minerals, chromite and chlorite. Spectral features of chromitite at 550 nm and 1100 nm are governed by electronic transition process in Fe³⁺ and crystal field effect in Fe²⁺ ions present in chromite structure respectively. On the other hand, spectral features at 1400 nm, 1900 nm and 2300 nm are related to the vibration of O–H, H–OH and metal hydroxide bonds in chlorite. Amongst these features, the spectral feature at 1100 nm (due to Fe²⁺ in chromite grains) is common to all three major textural varieties of chromitite samples studied here. Electron probe micro analysis (EPMA) data of chromite and chlorite grains of each texture are used to relate the presence and abundance of Fe₂₊ (in chromite grains) with absorption feature. Width of the 1100 nm feature has a correlation value 0.95, while depth of the same feature has a correlation value 0.94 with the abundance of chromite mineral estimated using modal analysis of chromite samples. Therefore, spectrometric parameter of 1100 nm spectral feature of chromitite can be used as proxy for estimating modal abundance of chromite in chromitite samples after estimating deposit specific correlation coefficient.

Keywords

Chromitite, Electronic Processes, Modal Analysis, Spectral Feature, Texture, Vibrational Processes.

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Biswajit Ghosh ¹, Namita Chakma ²

Affiliations
1 Khorad Amena High School, Satgachia, Purba Barddhaman 713 422, IN
2 Department of Geography, The University of Burdwan, Purba Barddhaman 713 104, IN

Abstract

In the present study we used the ecological footprint method to numerically measure the sustainability of agricultural production at the micro level. For this, two community development blocks of Barddhaman district, West Bengal, India were selected. As a consumption- based method, it is most suitable for measuring cropland footprint, biocapacity of croplands, and their ecological surplus and deficit status of an environmental indicator. The integrated result represents higher sustainability of agricultural system, but crop-wise assessment explores some negative aspects with respect to self-sufficiency of the study area that demand necessary transformation of existing cropping pattern.

Keywords

Agricultural Land Use, Biocapacity, Ecological Footprint, Sustainability.

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