@Walter Hinteler,
You are making an "either/or" argument where in reality more than one point can be true.
1. Reudicing the use of insectcides doesn't mean prohitibing the use of insecticides. Obviously reducing the use of insecticides is a good thing as long as it doesn't reduce crop yields.
It is a balance
2. I know about the importance of synthetic Nitrogren-based fertilizers because of my background in Physics and my stint teaching Earth Science in high school. The science of liberating Nitrogen for use of nitrogen is interesting in itself. There is no question that the development of synthetic fertilizers greatly reduced the amount of starvation in the world.
The "Haber" cycle is an intersting story in itself. Haber was German scientist who pushed the use of chemical weapons in WWI. There are some truly horrific stories about him including some quotes that no modern person would find palatable.
However, the Haber Cycle he developed was a revolution in agriculture and with out question has saved hundreds of millions of people from starvation. He understood this and wanted to be seen as helping to save the world by ending starvation.
It is a difficult historical figure. A man who killed and saved. But life is complicated, and that is how reality works.
1) Nitrogen based synthetic fertilizer is essential. There is no replacement that can be used on a global scale and without it hundreds of millions of people would die of starvation..
2) Nitrogen based syntetic fertilizer damages the environment and has caused drastic changes to local environments.
They are both true. You are going to have to make the value judgement yourself. But to deny facts that don't fit your narrative isn't reasonable,