The perrenial cover is like skin, you plow it up, nutrients start bleeding away. Even if you return all the stalks and harvest, after it has gone through people and animals, you have lost nutrients. It just steadily goes downhill. You get a dry spell, it can blow away. You are trying to defy nature.
Life binds elements together.
You kill a living field, you tear things apart. Torn apart, they are free to leave. And they do. Life exists in a balance of energy. If there is not enough energy reaching the field, it freezes, nothing grows.