<p>Nitrogen (N) fertilizer plays a crucial role in agriculture. The conventional production and use of solid nitrogenous fertilizers results in substantial energy consumption and severe groundwater pollution. Here we propose an absorption‒electroreduction relay strategy capable of the distributed production of directly accessible liquid N fertilizer (NH₄NO₃ solution) from NO_<i>x</i>, a common constituent of exhaust gases. When combined with plasma-driven N fixation, the raw feedstock in this strategy can be further extended to air. NO_<i>x</i> is first absorbed by an aqueous solution. The NO_<i>x</i>⁻ produced as well as the residual NO_<i>x</i> are selectively reduced to NH₄NO₃ by a ruthenium‒cobalt electrocatalyst (Ru₉Co₉₁). Through the N balance established between the absorption and electroreduction processes, NH₄NO₃ solutions are produced continuously without any other additive ions. We successfully constructed an 8-l membrane-free system that outputs 8.5 l h⁻¹ of NH₄NO₃ solution at a constant concentration (840 mg l⁻¹ of N) to meet the N fertilizer requirements for 20 m² of farmland. This work offers an alternative route for obtaining N fertilizers, with the potential to improve the sustainability of the N fertilizer supply.</p>