Nitrogen from mineral fertilizers allowed to increase the yields for majority of crops. Production of nitrogen mineral fertilizers requires huge expenditures of nonrenewable sources of energy at the industrial factories. Utilization of nitrogen from mineral fertilizers has many negative consequences on the environment (volatilization, with increased effect on global warming, leaching of nitrates which are polluting the groundwater, reduction of the content of soils organic matter and decreased biodiversity of soil flora and fauna, etc.). Biological nitrogen has many advantages relatively to the nitrogen from mineral fertilizers. Republic of Moldova has real possibilities for increasing the share of biological nitrogen in the total nitrogen consumption.