Abstract
This study was designed to assess the performance of plant growth promoting rhizobacteria (PGPR) containing ACC-deaminase for improving growth and yield of maize in the presence of organic fertilizer. Organic fertilizer was prepared by composting fruit and vegetable wastes in a locally-fabricated unit and enriched with N fertilizer applied @ 147 g kg(-1) compost. This 'organic fertilizer' was used to formulate bio-fertilizers by using three PGPR strains containing ACC-deaminase, Pseudomonas putida biotype A (Q(7)) Pseudomonas fluorescens (Q(14)) and Pseudomonas fluorescens biotype G (N-3), separately. The organic- and/or bio-fertilizers were applied to maize @ 300 kg ha(-1) without/with 88 kg ha(-1) urea-N in the field trials. A basal dose of P and K (100 and 50 kg ha-, respectively) was applied to all plots and also tested in the field trials in the absence of organic-/bio-fertilizer. Results of field study revealed that the organic fertilizer supplemented with 88 kg ha(-1) N was equally effective to full dose of N-fertilizer (175 kg ha(-1)) in improving cob weight, fresh biomass and grain yield of maize. However, bio-fertilizer Supplemented with 88 ha(-1) N fertilizer significantly increased the growth and yield of maize over full close of N-fertilizer and exhibited Superiority over organic fertilizer. Organic-/bio-fertilizer application also significantly enhanced N. P and K uptakes. The Pseudomonas fluorescens biotype G(N-3) containing biofertilizer was found best to increase grain yield and nutrient uptake both in the presence or absence of 88 kg N ha(-1). Results may imply that organic waste could be composted into value-added soil amendment by enriching/blending it with N and PGPR containing ACC-deaminase activity. This approach is based on using organic- or bio-fertilizers (N-enriched and Inoculated compost) at lower rates (just 300 kg ha-1) instead of tons ha-1 of non-enriched composts. Moreover, this strategy could also be useful to protect our environments against threat posed by organic wastes.
