Effect of bio-fertilizers on corn (Zea mays L.) growth characteristics in Cd-spiked soils

Abstract

To investigate the effect of bio-fertilizers on contamination rate of plants to heavy metals, an experiment was carried out in factorial based on completely randomized design with three replications in research greenhouse of University of Zanjan in 2015. Treatments were: contamination levels of soil to cadmium (Cd) (0, 10, 25, 50 and 100 mg kg−1) and inoculation with bio-fertilizers including phosphate-solubilizing bacteria Pseudomonas putida, mycorrhizal fungi Funneliformis mosseae and Rhizophagus intraradices. Measured characters include leaf chlorophyll index, plant height, shoot and root fresh and dry weight, phosphorus and potassium of shoot and root and Cd concentration in the plant. The results indicated that the use of bio-fertilizers increased the leaf chlorophyll index, plant height, shoot and root fresh and dry weight, phosphorus and potassium of shoot and root significantly in comparison with control. The treatment of F. mosseae and P. putida (M + P) could improve leaf chlorophyll index and plant height by 11.93 and 21.89% in comparison with control, respectively. The chlorophyll index significantly decreased with increasing contamination levels of soil to Cd. The simultaneous use of F. mosseae and P. putida (M + P) and Cd increased the shoot and root dry weight by 6 and 7% in comparison with treatment 100 mg kg−1. In addition, the results indicated that inoculation of soil with bio-fertilizers can decrease the harmful effects of Cd on plants’ growth and yield.