Fertility is perceived as an inherent property of the normal earth physical chemistry, climate, and interactive dynamics of living organisms. This definition of fertility has proven itself for 500 million years on this planet, and needs no improvement. Agriculture is not exempt from this obligation. To the extent that some cheat, others have to carry their load of duty, and if too many cheat that load cannot be made up by the faithful stewards. This is not a debatable point or issue.
All higher life kills to live, and all are eaten on the great recycling food chain.
The great law of nature is that everything is recycled eventually. That law applies to solar systems as well as local ecology. Some things which the human race has learned to make are more durable than can be reduced by normal processes in meaningful human timespans. Some things are toxic, and remain toxic for generations or even millions of years. No generation has any right to unleash such things for their descendents to deal with, and this includes farmers.