Selection and Potential Test of Indigenous Bacteria to Increase the Growth of Red Spinach (<i>Amaranthus tricolor</i> L.) on Saline Soil

Abstract Saline soil can potentially be used as productive land for agricultural cultivation. However, it has several obstacles, especially in the absorption of nutrients. High salt absorption can inhibit plant growth and can cause poisoning in plants. Overcoming the problem of salinity stress in saline soil requires the development of technological innovation by utilizing bacteria that play a role in reducing salinity stress and can increase agricultural production in saline soil. This study aimed to test the potential of indigenous bacteria on the growth of red spinach ( Amaranthus tricolor L.) in saline soil. This study was conducted at the Soil Biology Laboratory, Agrotechnology Study Program, Faculty of Agriculture, Universitas Sumatera Utara, Medan. This study used a Non-factorial Completely Randomized Design (CRD) with treatments N0 = Without Bacteria; N1 = Enterobacter cloacae; N2 = Brucella cicero; N3 = Bacillus cereus; N4 = Pseudomonas aeruginosa; N5 = Burkholderia gladioli; N6 = Priestia flexa; N7 = Enterobacter quasiroggenkampii; N8 = Achromobacter xylosoxidans; N9 = Ochrobactrum oryzae and N10 = Brucella oryzae . The results of the study showed that giving indigenous bacteria can increase the microbial population, shoot wet weight, shoot dry weight, plant height, stems number and diameter, roots wet weight up to 60%, roots dry weight up to 32%. In general, the best bacteria are Enterobacter cloacae (N1), Bacillus cereus (N3) , Priestia flexa (N6) , Achromobacter xylosoxidans (N8) and Ochrobactrum oryzae (N9).