Effectiveness of Organic-/Bio-Fertilizer Supplemented with Chemical Fertilizers for Improving Soil Water Retention, Aggregate Stability, Growth and Nutrient Uptake of Maize(Zea maysL.)

In this study, an organic-fertilizer was prepared by composting fruit and vegetable wastes in a locally fabricated unit and enriching it with N applied at the rate of 147 g kg−1 compost. This “organic-fertilizer” was also used as a carrier for PGPR strain, Pseudomonas fluorescens biotype G (N3) containing ACC-deaminase to formulate a bio-fertilizer. The organic- and/or bio-fertilizers were applied at 300 kg ha−1 to maize in pots/plots supplemented with 0, 88 or 132 kg ha−1 urea-N. A basal dose of P and K (100 and 50 kg ha−1, respectively) was applied to all pots/plots. Results of two-years' pot and field trials revealed that the organic-fertilizer supplemented with 88 kg ha−1 N was equally effective compared to full dose of N-fertilizer (175 kg ha−1) in improving root weight, fresh biomass, and ear and grain yields of maize. However, bio-fertilizer supplemented either with 88 or 132 kg N ha −1 significantly increased the growth and yield of maize over full dose of N-fertilizer and exhibited superiority over organic-fertilizer. Organic-/bio-fertilizer application significantly enhanced N and P uptakes while substantially reducing the rate of water loss from the soil and increased aggregate stability. 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. The novelty of this approach is that the organic- or bio-fertilizer was used at a low rate (just 300 kg ha−1). Moreover, this strategy could also be useful to protect our environments against threat posed by organic wastes.