Moldova has become a predominantly agrarian country, due to the favorable natural conditions, that allow obtaining high quality products, which makes it compatible in this respect on the world market. However, the expected crop yield depends on several factors, including the use of herbicides as a necessary remedy, on the other hand – damaging the environment. Under the above-mentioned aspect, research to reduce the negative effect of these substances has a priority character. Particular attention has been paid to the use of nanotechnology based methods in several countries in recent years. Investigations have shown that nanometric iron oxide particles are extremely effective in binding and removing arsenic from groundwater that affects the water supply of millions of people and for which there is no effective solution. Based on the above, our team of Soil Microbiology Laboratory starts from 2015 the researches to identify ways to intensify the bioremediation of soil polluted by pesticides using nanoparticles. Research purpose of this study was to identify the ability of iron nanoparticles to stimulate the interaction between nitrogen-fixing symbiotic microorganisms (Rhizobium meliloti 2/13) and the lucerne in soil conditions polluted with the herbicide trifluralin. The experiments were carried out for 12-17 days under climatic conditions with artificial lighting at 22-250 C. To perform the experiments we used Petri dishes with unpolluted soil, where the pre-processed lucerne seeds were introduced with the Rhizobium meliloti 2/13 suspension. Additionally, the soil was wetted with aqueous solution of Trifluralin (each time according to the planned concentration – from 1 to 400 mg/l). Fe++ nanoparticles were also used in experiments. As a result of the research, the following conclusions were made: 1. Trifluralin used in doses: 1, 10 and 20 mg/l adversely affect the development of lucerne plants. These doses do not have a negative effect on seed germination. 2. Trifluralin doses of 50, 100 and 200 mg/l insignificantly affeced the growth of bacteria Rhizobium meliloti 2/13. 3. Introduction of Fe++ nanoparticles (25 mg/l) favored the neutralization of high-dose inhibition of trifluralin (400 mg/l) in Rhizobium meliloti 2/13 bacteria. 4. Obtained data demonstrated that the herbicide trifluralin exerted a negative influence on the growth and development of plants and of the symbiotic-nitrogen-fixing microorganisms (Rhizobium meliloti). 5. Data obtained also shows that Fe++ nanoparticles have a positive influence on the growth and development of lucerne plants and the symbiotic-nitrogen-fixing microorganisms (Rhizobium meliloti 2/13).