The Role of Rhizobacterial Inoculum and Formulated Soil Amendment in Improving Soil Chemical-Biological Properties, Chlorophyll Content and Agronomic Efficiency of Maize under Marginal Soils

Abstract

Intensively use of chemical fertilizers accelerates organic matter and soil health degradation. Consequently, the soil capacity in providing the essential nutrient is decreasing significantly. The research was conducted to investigate the contribution of selected rhizobacteria inoculant as biofertilizers and formulated soil amendment (FSA) for enhancing the soil organic carbon, abundance of nitrogen fixer bacteria (NFB), phosphate solubilizing bacteria (PSB), chlorophyll content and yield of maize in marginal soils. The experiment was arranged as Randomized Complete Blocks Design (RCBD) consisting of two factors and provide with three replications. The first factor were biofertilizers (consortia of PSB and N-fixing bacteria combined with formulated soil amendment (compost 50%, biochar 20%, humid acid 1%, guano 9%) and the second factor were the rate of N,P fertilizers100%, 80%, 60%, 40% recommended doses (138; 110.4; 82.8; 55.2 kg ha-1 N and 36; 28.8; 21.6; 14.4 kg ha-1 P). The results revealed that application of biofertilizers and FSA increased soil C-org, population of PSB and N-fixing bacteria, chlorophyll leaves and yield of maize were increased significantly. The highest population of PSB and N-fixing bacteria, chlorophyll leaves and yield of maize were obtained by application of 1.200 g ha-1 of biofertilizers and 2 t ha-1 of organic FSA. The application of biofertilizers and FSA with 60-100% NP fertilizer could increase maize yields. Additionally, fertilizers efficiency was increased by 40 %. This finding recommends the use of 1200 g of biofertilizers inoculant and 2 t of FSA to improved the soil properties and increased the maize productivity on marginal soils.