In our formal farming systems, we used our physical energy and power to work in our farm land, but these days we all rely on chemicals substance that why we can no longer manage our farm land and that is why we need physical energy. The reason why land is getting less in fatal in teams of production is because when the reproduction is more than two to three teams in a particular piece of land the manual of the land will be very weak in sense that the seed will not germinate very well.
You sort of contradicted yourself at the end of your post. At the beginning you condemned the use of chemicals on land or farm and at the end you identified that not rotating farm is responsible for low harvest. Therein is the issue of chemicals and why it is important to help farm products to grow faster. If fertilizer is applied in a particular land during cultivation and fertilizer is not applied in the second farm, the former will grow faster and produce good fruit. Chemicals are used to support farm and that will help to increase the quantity of farm produce.