[lambdadmitry]

> most fertilizers are composed of chemicals derived from petroleum

Can you please elaborate further? Yep, in a lot of cases hydrogen for ammonia comes from natural gas. Nope, it doesn't have to be, in fact you can easily get it from water. What other "chemicals" do you have in mind?

> because these techniques are extremely modern

They are, but the concept of "not dying of famine" is also pretty modern if you consider an overall population.

> The problem with fertilizers… killing local ecosystem of bacteria and insects

I believe you confuse fertilizers with pesticides.

[chadgeidel]

The nitrogen in the fertilizer is creating dead zones: https://www.scientificamerican.com/article/fertilizer-runoff...

A quick googling will show many scholarly papers and articles describing this.