Concentrated factory made fertilizer was invented for the millions of farmers in this country that farm millions of acres of land every year. It would not be possible for a farmer to compose 2000 acres of land, compose would need to come in 100 train car loads day after day for weeks. Where would all that compose come from for a 1,000,000. different farmers to have enough for their 2000 acre fields? If it was not for factory made fertilizer there would be 95% less food in the grocery stores at a much higher price. People complain fertilizers are made from petroleum products, maybe some are but i know some fertilizer is mined and some are made from the chemicals in the air. Air we breath is about 70% nitrogen. If factories turn air into a produce that plants can use I see nothing wrong with that. If farmers plant crops year after year, with no fertilizer crops will become much small each year and become smaller and smaller year after year as the land is turned in to waste land that will not grow much. Farmers that plant corn the 1st year will plant beans the 2nd year to put nitrogen back into the soil so they can plant corn again the 3rd year then beans again the 4th year and so on. I should do that in my garden corn one year then beans and so on. A corn picker harvests 2000 acres of corn, chops the stalks and cobs into tiny pieces and spreads it all over the field that basically turns the whole 2000 acre field into one big compose. Combine that harvests 2000 acres of beans chops the plants and pods into tiny pieces then blows them out the back to compose the whole 2000 acre field. I do the same thing in my garden I just harvested all my corn the stalks are laying in full sun drying out, next week I will mow them with the lawn mower when I mow the grass and blow all the chopped pieces into the garden then till them in. That makes my garden the compose pile there is no compose bin in the corner of the yard that is just extra work.
I was reading online where it said, 96% of the people in this country grew a garden before World War 2 that number dropped to about 2% over the years.