The effect of plant growth promoting bacteria on growth and nutrient uptake of maize in two different soils

An understanding of ecological conditions effecting on bacterial inoculants is important when introducing microbes for increasing plant growth and productivity. In this study the influence of two different soil types on the stimulatory effect of plant growth promoting rhizobacteria for maize was investigated. The investigations were carried out in pot experiments with calcareous calcisol soil taken from Sirdarya, Uzbekistan and loamy sand from Muencheberg, Germany. The bacteria strains Pseudomonas alcaligenes PsA15, Bacillus polymyxa BcP26 and Mycobacterium phlei MbP18 had a much better stimulatory effect on plant growth and nitrogen (N), phosphorus (P) and potassium (K) uptake of maize in nutrient deficient calcisol soil. Their stimulatory efficiency reduced in relatively rich loamy sand soil where bacterial inoculants stimulated only root growth and N, K uptake of root. These results suggest that plant growth stimulating efficiency of bacterial inoculants affected by soil nutritional condition. The bacterial inoculation has a much better stimulatory effect on plant growth in nutrient deficient soil than in nutrient rich soil. (c) 2007 Elsevier B.V. All rights reserved.