Monitoring of lacZ marked Azotobacter and Pseudomonas in Wheat Nursery Soil Treated with Fly Ash

Abstract

Soil amended with different proportions of fly ash, a solid waste generated from coalfired thermal power plants, was evaluated as a soil conditioner and nutrient supplement on the growth of wheat (Triticum aestivum) nursery trial. Present study evaluated the growth of wheat in nursery soil treated with 0%, 5% and 10% fly ash and microbial consortium of Pseudomonas striata and Azotobacter sp. in different combination under six different treatments. pH and organic carbon (OC) content did not increased significantly in fly ash amended soil, but significant increase in electrical conductivity, available phosphorus and available nitrogen content of soil was observed after harvest. Soil amended with 5% fly ash and microbial consortium increased available nitrogen by 26% and available phosphorus by 48% as compared to control soil. Fly-ash alone and in combination with lacZ+ marked Pseudomonas and Azotobacter was evaluated for bioefficacy on wheat and their population buildup in fly ash treated soil. Overall 5% fly ash amendment in soil increased the percentage wheat germination. It was observed that, soil treated with fly ash and microbial consortium comprising of Pseudomonas and Azotobacter significantly enhanced crop yield. Soil amended with 5% fly ash increased the grain yield by 18% and shoot biomass by 15% as compared to control soil. However treatment comprising of 5% fly ash and microbial consortium increased the grain yield by 59% and shoot biomass by 30% as compared to control soil. Soil amended with 10% fly ash had nearly same impact as control soil which shows that it’s addition is not inhibitory for wheat growth. The results indicated that combined addition of fly ash and microbial inoculants can be used for improving survival rates and crop growth and fly ash at 5% dose can be used on a large scale to boost soil fertility and crop productivity. Owing to the heterogeneous nature of fly ash it can be applied in soil only in conjunction with microbial inoculants, which can be used to design a soil benefaction strategy.