Effect of Intercropping Mango with Lemongrass and Screwpine on the Soil Carbon Dioxide Flux and Soil Microbial Density

Background: An intensification of mono-cropping system has been increasing greenhouse gas emissions and loss of biodiversity. Intercropping offers a potential alternative to mono-cropping in lowering the environmental influences on agriculture. Virtually, no information is available on how intercropping with aromatic plants influences soil agroecosystems and hence present study was conducted to evaluate the effects of intercropping mango (Mangifera indica) with lemongrass (Cymbopogon nardus) and screwpine (Pandanus amaryllifolius) on soil CO2 flux and microbial density vis-a-vis mango monocrop. Methods: The field trial involves mango-screwpine intercrop, mango-lemongrass intercrops and mango monocrop. The soda lime method was used for the measurement of soil CO2 flux. Soil microbial density was assessed by using the spread plate method with Beijerinkia and Pikovskaya medium. Result: The results indicated that intercropping with aromatic plants increased the carbon allocation in promoting the root growth and thereby reduced the soil CO2 emission. In addition, intercropping plots had large number of phosphate-solubilizing microorganisms than the mono-cropping. To finetune the findings of the experiment on the dynamics of soil nutrients, further study in protected environment is required.