Effects of microbial bio-fertilizers on soil physicochemical properties under different soil water regimes in greenhouse grown eggplant (Solanum Melongena L.)

Abstract

ABSTRACT The aims of this research were to investigate the effects of microbial bio-fertilizer (BF) application on physicochemical properties of sandy-clay-loam (SCL) soil under three different soil moisture regimes in greenhouse-grown eggplant (Solanum melongena L.). Correlations between the physicochemical soil properties in a greenhouse condition were determined. The microbial bio-fertilizers included Azotobacter chroococum and Azotobacter vinelandii. Experiments were conducted in randomized plots design with three replications. Three different irrigation levels (100% (I100), 60% (I60) and 40% (I40) of field capacity-FC) were applied. Post-harvest soil samples were analyzed for soil physical and chemical characteristics. Bio-fertilizers had positive impacts on physicochemical soil properties. Bio-fertilizers accelerated mineralization of organic residues, thus improved the availability of macronutrients (N, P, K, Ca, and Mg) and micronutrients (Fe, Mn, Zn, and B). The highest total N value (0.143%) was observed in I100 treatment of bio-fertilizer (BF+I100) and the lowest total N (0.087%) was observed in I40 treatment without bio-fertilizer. Bio-fertilizers improved aggregate stability, total porosity, moisture-retention capacity and infiltration rate, and decreased bulk density of the soils. Bio-fertilizers increased water uptake and decreased drought susceptibility of the plants. It was concluded that bio-fertilizers could reliably be used to improve soil physical and chemical characteristics under different irrigation levels.