APPLICATION OF ENDOPHYTIC PSEUDOMONAS STUTZERI AND REDUCE DOSE OF INORGANIC NITROGEN FERTILIZER ON THE GROWTH AND THE YIELD OF RICE CULTIVATED IN CONTINUOUS THREE RICE CROPS SYSTEM IN MEKONG DELTA, VIETNAM.

Mineral fertilizers have been used to increase rice yield, however, excessive use of agrochemicals in rice production caused residue toxicity and environmental pollution through leaching and evaporation. The decreased use of synthetic fertilizers was recommended to maintain the sustainable agriculture system. This article reports on the impact of plant-growth promoting rhizobacteria (PGPR) on rice cultivation in acid sulphate soil in the Mekong Delta, Vietnam to achieve a better harvest index and reduce environmental pollution. A greenhouse and field experiments were carried out in such condition to study the effect of Pseudomonas stutzeri on the growth and yield of local rice variety OM1490 cultivated in Bac Lieu province. The results showed that rice inoculated with P.stutzeri using 50%N/ha of inorganic fertilizer improved yield components and rice yield equivalent to those of rice grown with 100%N/ha of inorganic fertilizer without inoculation. Root length of inoculated rice with 50%N/ha was significantly longer than those of uninoculated rice without nitrogen fertilizer. This feature was crucial to climate change in drought areas. The findings suggest that P. stutzeri with decreased dose of N/ha could promote rice growth and yield compared to the higher dose of N/ha without P.stutzeri inoculation. Keywords: effect, inoculate, inorganic fertilizer, paddy, plant growth-promoting rhizobacteria.