The effect of a small sodium additive on the electron-ion recombination in a decaying nitrogen plasma is studied. Time variations in the plasma conductivity during plasma decay are measured experimentally and used to calculate the corresponding time dependences of the electron density for various concentrations of the sodium admixture. The results obtained demonstrate that it is possible to decrease the rate of charged-particle loss by doping a small alkaline admixture to nitrogen. It is shown that the observed increase in the lifetime of charged particles is related to the fact that, in a nitrogen-alkaline plasma, three-body recombination plays a significant role in charged-particle loss, whereas, in a pure nitrogen plasma, the main mechanism for charged-particle loss is dissociative (two-particle) recombination.