Role of Molybdenum in Relationship with Rhizobium sp. and its Effect on Physiological Characteristics and Soybean Production

Abstract

Background and Objective: Molybdenum (Mo) is a micro nutrient that plays a role in activating the nitrogenase enzyme needed by Rhizobium bacteria to form root nodules in legume plants and every bacteria that fixes nitrogen requires molybdenum during the fixation process. The objective of the research was to evaluate the role of Mo in increasing the effectiveness of N2 fixation and determine the response to soybean seed production and quality. Furthermore, it focused on collecting physiological and soybean production data. Materials and Methods: The study was conducted at Medan Selayang, Medan, Sumatera Utara from June to August, 2022. This research was conducted in an experimental field, using a factorial randomized block design with 2 factors and 3 replications. The first variable was Mo treatment at 0, 200, 400 and 600 g haG1. The second was the application of Rhizobium sp., inoculant at 0, 5 and 10 mL/polybag. The variables observed include chlorophyll, cuticle thickness, number of pods, number of filled pods, seed dry weight/sample, 100 dry seed weight and protein content. Results: The combination of Rhizobium sp., inoculation at 5 mL/plant and 200 g haG1 Mo fertilizer produced the highest chlorophyll content and total chlorophyll. However, the highest cuticle thickness was produced without inoculation at 5 and 10 mL/plant. Rhizobium sp., inoculation at 5 mL/plant and 600 g haG1 Mo increased the number of filled pods per plant to 92.73 pods, seed dry weight per plant and seed dry weight per plot. Conclusion: Inoculation of Rhizobium sp., 5 mL/plant and 600 g haG1 molybdenum increased the number of filled pods per plant, seed dry weight per plant and seed dry weight per plot respectively 18.82, 29.13 and 13.89%.