Currently, the chemical agrochemicals including fertilizers and pesticides were used very much on green onions,
leading to contamination of agrochemicals on agricultural products, soil and water and seriously affecting consumer health, the environment and ecology. Therefore, the research focused on using microbial and biological products inthe cultivation and production of green onion in order to limit the useof inorganic fertilizers and pesticides, contributing on improving the value of onions is really necessary. The objective of the study was to evaluate the efficacy of salt tolerant bacterial product, NPISi containing biologically nitrogen fixing, phosphate solubilizing, IAA synthesizing, and Si solubilizingbacteria in a combination with spraying plant protection biological product (PPBP) from garlic, chili, ginger, lemongrass, anise, and cinnamon on growth, yield, pest and disease control ability on green onion, and soil properties in Tran De district, Soc Trang province, Vietnam. The experiment was arranged in a completely randomized block design with 8 treatments and 4 replications on the in two consecutive crops. The results showed that the treatment applied of 80 kg/ha of NPISi inoculant combined with 6% PPBP sprayed every 10 days enhanced plant height, number of buds/hill, number of leaves/hill, stem diameter and yield of green onion up to 45% as compared to the control treatment received the sameamount of recommended NPK dose. Moreover, the treatment applied with
NPISi and PPBP in combination with 50% NP + 100% K had green onion yield equivalent to the treatment received
recommended 100% NPK fertilizer after two consecutive crops. Besides, the use of NPISi inoculant and PPBP also improved pH and the number of bacteria in soil. Concurrently, the use of PPBP also effectively controlled of the tube borer numbers on green onion.