Background: Vermicompost is a manure produced from organic waste through the activity of epigeic earthworms and microbes. Excessive use of chemical fertilizers for long term to increase the crop productivity have led to deterioration of soil health. Therefore, to assess the effect of vermicompost, as an alternative option to chemical fertilizer, on tea yield and earthworm population, field application of vermicompost on tea plantation was carried out for a period of two years (2015-2016) in Harishnagar Tea Estate, West Tripura, India. Methods: The experimental plot (25 sq. m) was set up using a random block design with 4 different rates of vermicompost viz. T0 (Control), T1 (5 t ha-1 year-1), T2 (10 t ha-1 year-1) and T3 (15 t ha-1 year-1) each having five replications. Composite soil samples were collected at the beginning and at the end of the experiment. Earthworms were also collected during the experimental period.Conclusion: Application of vermicompost significantly influenced the tea plantation soils, increased the tea yield along with earthworm population and was dependent on the vermicompost doses applied.

Aim :Methodology : Results :Interpretation : Tea () is an economically important and intensively managed cash crop in the northeast India. As earthworms represent the highest soil biomass and are good indicators of soil health, the main objective of the study was to find out the impact of conventional management practices (anthropogenic interference) on earthworm biodiversity and relative density of exotic and native species in tea agro-ecosystem.Earthworms were collected adopting TBSF soil monolith (25 cm x 25 cm x 40 cm) by digging and hand-sorting method in the managed tea plantation and degraded tea plantation of Tripura. Physico-chemical parameters of soils (temperature, moisture, organic matter, pH), biological parameters viz., earthworm density, biomass, relative density and ecological parameters (indices of diversity, dominance) were measured.Anthropogenic interferences had greatly influenced the earthworm diversity in tea plantations. Out of total seventeen earthworm species, thirteen and fifteen earthworm species were recorded in the managed tea plantation and degraded tea plantation, respectively. Density (56 ind. m ) and biomass (27 g m ) of exotic species in managed tea plantation were significantly higher (p<0.01) than those of degraded tea plantation (23 ind. m , 17 g m ). Exotic species, and native species, were the dominant species of managed tea plantation and degraded tea plantation. Significantly higher (p<0.01) index of dominance (0.73), lower diversity index (0.66) and lower species richness (0.31) were observed in managed tea plantation compared to those of degraded tea plantation (dominance 0.37, diversity 0.89, species richness 0.77) Low earthworm diversity with high dominance of exotic species in managed tea plantation was due to high anthropogenic activities that favoured the exotic earthworm species over native species. Camelli sinensis Pontoscolex corethrurusDrawida assamensis -2 -2 -2 -2

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