Increasing Soil Fertility ideas?

So I have this seed planted in a soil with very low fertility. Ideas on how I can increase the fertility in the future are welcome. You dont get proper fertilizers where I live. So I have been thinking of fish water, egg shells, tea bags, coffee grinds, milk. If anyone has used any of these with good results, PLEASE share your experience.

You need poop.horse poo cow poo bat poo,some kind of poo to mix with the soil.there is poo in every state in the country.If not poo then you have to go synthetic or chemical.Egg shells and coffee grinds are for growing flowers and shit.Though human hair is a source of slow release nitrogen,still not suitable for growing mj

Got a Home Depot or Lowe's close by? If so, pick up some Espoma Bio-tone or Plant-tone and mix in soil per directions. Another product line to consider is Jobe's Organics (not the spikes), which I happen to be using now. It has mycorrhizae, as does the Espoma Bio-tone.