In-vitro Evaluation of Soybean Nodules Associated Bacteria for Their Plant Growth Promoting Ability on Agricultural Soils in Center of Côte d’Ivoire

Abstract

The overuse of chemical fertilizers poses significant risks to preserving the environment, food safety and human health. As sustainable alternatives, plant growth-promoting rhizobacteria offer a ecological approach to improving plant productivity and soil fertility. This study aims to assess the plant growth promoting (PGP) traits of 10 bacterial isolates derived from soybean nodule in order to select the most efficient ones and use them as biofertilizers. These bacterial isolates were tested for their PGP characteristics such as AIA and ammonia production, phosphate, potassium and calcium solubilization.   AS results, 60% of isolates produced IAA, 100% ammonia, 60% solubilized phosphate and 40% solubilized potassium and calcium. Two (02) isolates (RSC323, RSC325) showed several characteristics of plant growth promoting. But, one isolate (RSC323) was fund to be most efficient. It shown the higest solubilization indices, PSI (381.48±16.97%), KSI (211.11±19.24 %) and CaSI (220.00±40.00%) and produced more IAA and Ammonia. These results suggest that the selected rhizobacterial strains have significant potential as biofertilizers to support sustainable agriculture in tropical ecosystems. Future work should focus on the identification of 16S rRNA genes and field trials to confirm their effectiveness in promoting plant growth under natural conditions.