In his fascinating book, Dirt: The Erosion of Civilizations, David Montgomery traces the collapse of every civilization back to its original cause: soil erosion. The reason it's fascinating is that you already know the history of the rise and fall of these civilizations, but the perspective of soil erosion casts it all in a whole new light.
Rome fell because it overextended itself. Yes, but why did it overextend itself? Because it was following the same pattern every other civilization has followed throughout history: First, people settle in a fertile valley. They grow crops and their population starts growing. They need to put more land under cultivation, so after they use all the land in the fertile valley, they begin farming the slopes.
Plowing slopes causes accelerated soil erosion. And down in the valley, the intensive agriculture slowly depletes the topsoil. The land produces less and less food per acre, but the population is still growing. The only alternative to mass starvation is to gain more farmland. That's when conquest begins.
But couldn't they prevent topsoil erosion? The answer is yes, but they didn't. Roman farmers knew how to prevent the soil from being depleted — they knew about crop rotation, adding manure and other organic material to the soil, terracing slopes, etc. — but the demand for food from the growing population was so urgent, few farmers felt they could afford the time and effort it would take to care for the soil, and besides that, soil depletion is slow. It takes generations. The land becomes slowly less productive. But this year, the farmer needs to grow what he can — this is the position most farmers have been in throughout history.
But eventually, soil depletion caught up to every civilization that has ever existed. Either they expanded too far and were depleted by war, and/or food shortages caused rebellion and ultimately the overthrow of the government.
The ultimate source of their collapse can be traced back to the loss of topsoil.
As Montgomery put it, "Soil erosion that outpaced soil formation limited the longevity of civilizations that failed to safeguard the foundation of their prosperity — their soil."
Holistic Management allows vast areas of the world to produce highly nutritious food without creating soil erosion. In fact, it creates soil formation — the soil becomes richer and more fertile over time. And it simultaneously reverses desertification, solves water shortage problems, prevents floods and droughts, and increases biodiversity and wildlife.
Read more: How to Stop Two Thirds of the Earth From Turning Into a Desert.