We investigate Ag atom bonding to zigzag graphene ribbons and properties of these systems to increase the understanding of spin transport. Results concerning the total energies preferred binding sites, equilibrium distances, and electronic character for Ag adatoms on ZGNR are predicted in this study. The study also provides insight into the diffusion kinetics of adsorbed Ag atoms on zigzag edged graphene nanoribbons. The ribbons considered in the present work have an antiferromagnetic ground state and undergoes transition from semiconducting to half-metallic on spin polarization. DOS profiles of Ag-adsorbed ZGNR at the bridge site reveals low DOS across the Fermi level ensuring its semiconducting character, validated from the unpolarized spin calculations. Though nonlinear at biases less than 1V in the FM and AFM calculations, the spin current of atop adsorbed ribbon increases rapidly with the increase of the bias voltage beyond 1V.