Community-level management of bio-resources for augmenting income from coconut-based farming systems in Kerala state, India

On-farm management of farm residues for mass multiplication of beneficial microbes plays an important role in organic farming as well as integrated nutrient management by improving soil health. Community-level production of organic inputs from crop residues can be a potential source of income for farmers’ groups also. A large scale operational research on community-based bio-resource management, along with soil test based nutrient management, was undertaken by ICAR-CPCRI with financial support from NABARD in the major organic tract of Kerala in the coastal belt - Kanjikuzhy block during 2014-2016. The bio-resource management components under technology integration included farm-level production of organics from crop residues, enrichment using bio-agents, utilization of enriched organics for soil and plant health management and production of bio-primed planting materials. For enhancing the efficiency of Trichoderma-enriched organic manure, two ideal media viz., coir pith compost + neem cake (4:1) and coir pith compost + neem cake + poultry manure + cow dung (2:1:1:1) were standardized. Coconut seedlings produced through bio-priming with Trichoderma sp. showed early germination (90%), higher recovery percentage (79.5%), higher collar girth (17 cm), more number of fronds (9) and height (160 cm). Farm-based participatory action management integrating cost-effective bio-resource management interventions in coconut-based farming systems resulted in improvements in income from coconut by 26 per cent and intercrops by 142.9 per cent, contributing to an increase in the average farm income by 149.8 per cent. The average knowledge index of the respondents related to bio-resource management increased by 115.8 per cent and that of integrated nutrient management by 74.5 per cent

Diversification of coconut based farming system through community based organizations for income generation and sustaining productivity

Community based organizations (CBO) were formed in three coconut growing areas in Kerala during 2005-2008 and through farmer participatory process, various technological interventions for diversification of cropping system appropriate to the local community as well as subsidiary enterprises were taken up for income generation. The interventions included (a)intercropping with various crop species (cash and food security crops) aiming at year round farm income, (b) subsidiary enterprise comprising of animal husbandry component, (c) product diversification and value addition of coconut and intercrops as well as, (d) recycling of waste biomass through vermicomposting. The project not only brought out significant change in area put under crop diversification by way of inter/mixed cropping, but also in the average income derived from such farming system. Significant improvement in income was achieved through crop and enterprise diversification. While inclusion of various intercrops improved the share by 83 per cent compared to the income from coconut alone, it was up by 195 per cent when subsidiary enterprises like rearing of live stock and value addition were also considered, thus indicating the sustainability of crop and enterprise diversification in the project areas. The significant reduction in the value of Herfindahl Index, a measure of diversification, from 0.70 to 0.57 signified the improvement in the extent of diversification in various CBOs. Diversification of crops and adoption of coconut-based subsidiary enterprises through CBOs were found to be ideal strategies for sustaining productivity and rural upliftment in terms of income generation

Blue luminescence of Au nanoclusters embedded in silica matrix

Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO2 matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar+ irradiation on Au [40 nm]/SiO2 at various fluences and subsequent annealing at high temperature. The blue bands above ~3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 eV and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blue shift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals (FP-LAPW+LO) formalism with generalized gradient approximation (GGA) for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states (JDOS) for different strain values in order to explain the blueshift of ~0.1 eV with decreasing cluster size around L-symmetry point.Comment: 13 pages, 7 Figures Only in PDF format; To be published in J. of Chem. Phys. (Tentative issue of publication 8th December 2004

Crystal structure, superconductivity and magnetic properties of the superconducting ferromagnets Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0 - 0.6)

The structural, electrical and magnetic properties of the superconducting ferromagnets, Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0-0.6) are systematically investigated as a function of Dy doping and temperature. These compounds are characterised by high temperature superconductivity (Tc ranging from 20-40 K depending upon the Dy content) coexisting with weak ferromagnetism with two magnetic transitions (TM2 ranging from 95-106 K and TM1 around 120 K). Doping with Dy gives no significant structural changes except for a minor change in the c/a ratio. However the superconducting transition temperature is significantly suppressed and magnetic ordering temperature enhanced on Dy doping. These effects are described and discussed.Comment: 21 pages, 6 figures, 1 tabl

Multi-phonon Raman scattering in GaN nanowires

UV Raman scattering studies show longitudinal optical (LO) mode up to 4th order in wurtzite GaN nanowire system. Frohlich interaction of electron with the long range electrostatic field of ionic bonded GaN gives rise to enhancement in LO phonon modes. Good crystalline quality, as indicated by the crystallographic as well as luminescence studies, is thought to be responsible for this significant observation. Calculated size dependence, incorporating size corrected dielectric constants, of electron-phonon interaction energy agrees well with measured values and also predict stronger interaction energy than that of the bulk for diameter below ~3 nm.Comment: 13 pages, 5 figures, Journa