Effect of interspecific root interaction on soil nutrition, enzymatic activity and rhizosphere biology in maize/peanut intercropping system.

Pot experiment was carried out at different nitrogen levels in maize and peanut intercropping system to investigate the mechanisms that govern interactions between intercropped species in soil rhizosphere. Three different nitrogen levels 100%, 75% and 50% of normal nitrogen application rate were used in maize monoculture. Two peanut plants were intercropped with single maize plant per pot. Effect of reduced nitrogen application was investigated in soil rhizosphere by measuring soil enzymatic activity, nutrition, soil microbial diversity and composition. Phospholipid fatty acid (PLFA) was carried out to understand about composition of viable soil micro flora and community level physiological profile (CLPP) was applied to work out the microbial diversity. The results revealed that soil nutrition and enzymatic activities were higher in intercropping treatments as compared to mono-cropping with similar level of nitrogen. The results of PLFA analysis showed that intercropping inhibited the fungal population and promoted the bacterial community. The results of AWCD showed that 4 kinds of carbon utilization sources (carboxylic acid, polymer, amines & carbohydrates) increased by the decrease of nitrogen levels in intercropping treatments and other 2 kinds of carbon sources (phenolic acids & amino acids) showed different trend. Cluster analysis (CA) and Principal component analysis (PCA) carried out from the results of PLFA and CLPP indicated distinct separation amongst all treatments of monocropping and intercropping as well as with different level of nitrogen application that reflected a variation in soil microbial activity and composition. However intercropping treatment with 75% nitrogen level performed similar to 100% monocropping treatment of maize. The results revealed that by intercropping of peanut with maize can be used to decrease the dependence on artificial fertilizer which provides a convenient organic farming model for growers across the world.