OUT OF THE EARTH

CIVILIZATION AND THE LIFE OF THE SOIL

DANIEL HILLEL

UNIVERSITY OF CALIFORNIA PRESS                       1991

PART 1

 

Acknowledgements

A few years ago I was invited to deliver a public lecture to the faculty and students of the University of Massachusetts on the basic principles and current issues of my profession of soil and water science, as a vital aspect of environmental science. The honor entailed the challenge of presenting the essentials of that profession to the educated public in a way that would be succinct and interesting, yet not superficial. The challenge stayed with me long after that lecture was delivered, and it impelled me to undertake the larger effort that has culminated in this manuscript. I wish therefore to express my gratitude …

 

PART I: FOR SOIL THOU ART

Chapter 1: Prologue

All terrestrial life ultimately depends on soil and water. So commonplace and seemingly abundant are these elements that we tend to treat them contemptuously. The very manner in which we use such terms as “dirty”, “soiled”, “muddled”, and “watered down” betrays our disdain. But, in denigrating and degrading these precious resources, we do ourselves and our descendants great – and perhaps irreparable – harm, as shown by the disastrous failures of past civilizations.

Before I began my research, I had held the rather prevalent idea that human abuse of the environment is a new phenomenon, mostly a consequence of the recent population explosion and of our expansive modern technological and materialistic economy. Ancient societies, I presumed, were more prudent than ours in the way they treated their resources. For the most part, that has turned out to be a romantic fiction. My research has led me to the conclusion that manipulation and modification of the environment was a characteristic of many societies from their very inception. Long before the advent of agriculture, humans began to affect their environment in far-reaching ways that destabilized natural ecosystems.

In many of the older countries, where human exploitation of the land began early in history, we find shocking examples of once-thriving regions reduced to desolation by man-induced soil degradation. Some of these civilizations succeeded all too well at first, only to set the stage for their own eventual demise. Consider, for example, the southern part of Mesopotamia (“the land between the rivers”) which, as every schoolchild knows, was a great “cradle of civilization.”  We need only fly over this ancient country, now part of Iraq, to observe wide stretches of barren, salt-encrusted terrain, crisscrossed with remnants of ancient irrigation canals. Long ago, these were fruitful fields and orchards, tended by enterprising irrigators whose very success inadvertently doomed their own land.

The poor condition of the “Fertile Crescent” today is due not simply to changing climate or to the devastation caused by repeated wars, though both of these may well have had important effects. It is due in large part to the prolonged exploitation of this fragile environment by generations of forest cutters and burners, grazers, cultivators, and irrigators, all diligent and well intentioned but destructive nonetheless. The once-prosperous cities of Mesopotamia are now tells, mute time capsules in which the material remnants of a civilization that lived and died there are entombed. Similarly ill-fated was the ancient civilization of the Indus Valley in present-day Pakistan.

A haunting example of soil abuse on a large scale can be seen in the Mediterranean region, which has borne the brunt of human activity more intensively and for a longer period than any other region on earth. Visit the hills of Israel, Lebanon, Greece, Cyprus, Crete, Italy, Sicily, Tunisia, and eastern Spain. There, rainfed farming and grazing were practiced for many centuries on sloping terrain, without effective soil conservation. The land had been denuded of its natural vegetative cover, and the original mantle of fertile soil, perhaps one meter deep, was raked off by the rains and swept down the valleys toward the sea. That may have been the reason why the Phoenicians, Greeks, Carthagenians, and Romans, each in turn, were compelled to venture away from their own country and to establish far-flung colonies in pursuit of new productive land. The end came for each of these empires when it had become so dependent on faraway and unstable sources of supply that it could no longer maintain central control.

The inability to ensure a dependable supply of water has also been a frequent cause of failure. A poignant example is the sad fate of Fatehpur Sikri, the magnificent capital built in northern India in the late 16^th century by the Moghul emperor, Akbar the Great. Less than two decades after its completion, notwithstanding the splendor of its architecture, Fatehpur Sikri was abandoned entirely, for no other reason than the simple lack of water. Still more significant were the chain-well systems developed in ancient Persia. Some of these have remained in operation for several millennia, while abandoned remnants of others stand as mute testimony to the dangers of groundwater mismanagement.

There were, on the other hand, a few societies that did better than others. Some ingenious and diligent societies developed technologies that enabled them to thrive in difficult circumstances for many centuries. Judicious management of soil and water is exemplified in some of the arid regions of the Near East and the American Southwest. Equally impressive is the evidence regarding the long-lasting wetlands-based societies of Meso-America and South America. Remarkably productive wetland management systems have survived intact in China and other parts of Southeast Asia. In contrast with the historic failures of Mesopotamia and the Indus Valley, the irrigation-based civilization of Egypt sustained itself for more than five millennia – though it is now beset with problems of unprecedented severity.

Every one of the insidious man-induced scourges that played so crucial a role in the decline of past civilizations has its mirror image in our contemporary world. But it seems that the mirror is warped, and the problems it reflects are magnified and made monstrously grotesque. Human treatment of the environment has grown worse, and in our generation it has brought us to a point of crisis. Salinization, erosion, denudation of watersheds, silting of valleys and estuaries, degradation of arid lands, depletion and pollution of water resources, abuse of wetlands, and excessive population pressure – all are now occurring more intensively and on an ever-larger scale. Added to the old problems are entirely new ones, including pesticide and fertilizer residues, domestic and industrial wastes, the poisoning of groundwater, air pollution and acid rain, the mass extinction of species and, finally, the threat of global climate change.

Among the most egregious examples of latter-day abuse is the drying of the Aral Sea in the USSR, once the world’s fourth largest fresh-water lake, now made briny and charged with poisonous chemical residues. An even greater disaster is the progressive decimation of the tropical rain forests and the resulting wholesale eradication of entire ecosystems. Intensified runoff, accelerated erosion, and flooding of lowlands are now widespread, and in places – for example, in Bangladesh – the results are disastrous. The degradation of vegetation and land in arid regions, a process called desertification, is occurring on a continental scale in Africa and elsewhere. Irrigated lands in such disparate countries as Australia, Pakistan, India, USSR, and the United States are losing their initially bountiful fertility and in district after district are being withdrawn from production.

Yet there are hopeful developments, too. We know much more about the natural and man-induced processes at work; we understand and can anticipate some of their consequences. Degradation and pollution are not inevitable. They can be controlled. We can avoid the major abuses and devise better modes of environmental management. Land and water husbandry can be improved and sustained.

• While helping to establish the first settlements in the highlands of the Negev Desert, I had the unique opportunity to witness the compression of four millennia in the history of land and water management into a mere score of years.
• Following my experience in the Negev, I was asked to undertake a very different kind of mission to the tropical rain forests and drenched river valleys of Southeast Asia.
• My experience there and later in other parts of the Third World led me to realize the fallacy of our initial, simplistic assumption that, given enough machinery, fuel, chemicals, and know-how from the outside, underdeveloped lands could be reclaimed straightaway and cultivated without any serious environmental, social, and economic problems.
• During the 1960s and early 1970s, I took part in the intensive effort to improve the efficiency of water-use that resulted in doubling crop yields while reducing average crop water requirements by one-third – a singular achievement of the State of Israel.
• I believe that any rational control over the impact that human activity has on the environment must be based on a fundamental understanding of the processes at work.
• It is in the interest of promoting and disseminating such an understanding that I have undertaken this book.

 

Chapter 2: Man’s Role on God’s Earth