Farmers today still understand this - better than most non-farmers appreciate. Anybody still farming today is a decent business person, and that means making sure your land stays healthy so your farm has a future.

Industrial fertilizers have definitely changed the rules and allow farmers to shift the traditional cycles, but the same principles of caring for the land still apply. Crop rotation is still common, but some land is so much more productive for some uses than others that it makes sense to "weight" the rotation with fertilizers.