You don’t need carbon for fertilizer. Hydrogen is harvested from methane which is added to atmospheric nitrogen to make ammonia, the basis for all nitrogen comp

You don’t need carbon for fertilizer. Hydrogen is harvested from methane which is added to atmospheric nitrogen to make ammonia, the basis for all nitrogen compounds used for fertilizers. You can change the process slightly to use other sources of hydrogen but they’re considerably more expensive. If you were synthesizing anyway, you would not take a detour to methane.