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Pillar of Sand: Can the Irrigation Miracle Last?

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Sandra Postel goes well beyond a simple answer to the question posed by her subtitle 'Can the Irrigation Miracle last?' This book is an important resource for anybody trying to understand why water scarcity is such a major and escalating problem at the dawn of this century. Rather than adding to the generalist debate of the economists on water as a commodity or the projection into future problems presented by policy analysts and environmentalists, Postel analyzes particular examples in the past to explain the present and to make recommendations for the future.

Postel opens by reviewing major early societies in history, from Mesopotamia to Babylon, Egypt to ancient China, showing how they developed into major civilizations and why they fell. Yes, fell. Almost all great irrigation-based civilizations (Egypt being a rare exception) collapsed as a result of reallocation and overuse of water resources resulting in salinization, silting, soil degradation, etc.

Have we learned any lessons form the past? Postel argues that it does not seem so. She gives a factual account of a wide range of irrigation systems of the modern era, comparing methodologies and results to those in the past. The development of huge irrigation areas in India (Punjab), China and the US have either already demonstrated a repeat of the old mistakes or will do so in the near future. The groundwater tables are overused without being replenished and aquifers are tapped that have little chance to recover even in the long term. She describes two kinds of water wars: farms versus cities and nature and irrigation versus water scarcity. Water is reallocated and shifted from one use to another, but in some way, we are all living downstream from somebody else. Robbing Peter to pay Paul has its limits: the earth's fresh water resources are finite.

Against the backdrop of increasing water scarcity around the globe, Postel sees as humanity's main challenge the growing of enough food for our future population in a sustainable manner. She describes the pitfalls and the short-term fixes that will result in even greater problems in the future. At the same time, given the substantial increase in crop yield thanks to irrigation, she is realistic in her assessment that agriculture will not be able to do without it. As a result, the objective will have to be to reduce the amount of water we use for agriculture while at the same time producing more crop per drop of water.

Postel has traveled the world to review water systems, big and small, wasteful and efficient. Water needs saving in all areas of use, industrial, private and in agriculture. As agriculture uses by far the most of the global water resources, savings here will have major impacts down the line. She demonstrates on the basis of examples and statistics what is possible and how irrigation in agriculture can become highly effective and water conserving and restraint. She touches on the need to develop 'water-thrifty' plants, but, unfortunately, does not examine the traditional African crop varieties that are known to be drought tolerant and pest resistant. Postel appears to underestimate the importance of crop biodiversity; focusing on 'major' crops like wheat, maize and rice. Traditional farming systems developed in the earth's drylands could teach modern agriculture some important lessons.

Her main conclusion is that water management systems, whether public or private are most successful when they involve the local users and are based on a fair sharing of water resources at the community levels. Water markets and water trading provide options for the future as long as there is a fair and equitable basis for water access and use.

'Pillar of Sand' is clearly presented and easy to read. It will remain an important book in the intensifying debates around water use and mis-use, the increasing tension around demands between agriculture and other uses, and the privatization of water resource systems and the right of human beings to have the essential water they need to live.

The expansion of irrigation world wide has made a major contribution to increased food production, but for many years the World Watch Institute and the Earth Policy Institute have called attention to the danger of falling water tables and rivers that no longer reach the sea. Although China increased grain production from 90m tons in 1950 to 392 million tons in 1998, this was achieved at the price of rapidly falling water tables with the result that consumption exceeded production in four of the last five years; very soon China will be importing 30 - 50 million tons of grain annually, putting pressure on world grain prices. As wheat requires 1000 tons of water to produce one ton of wheat, the key challenges are: "how can we meet growing human needs for irrigation water without destroying the health of rivers, lakes and other aquatic systems? How can we grow enough food in a sustainable manner?" History tells us that most irrigation-based civilizations fail. The question we must address is "Will our civilization be different?"

Settled agriculture started 10,000 years ago in Mesopotamia but around 4,000 BC enterprising Sumerian farmers in the Fertile Crescent - present day Iraq - diverted water from the Euphrates to prevent crops withering before harvest. Irrigation allowed farmers to grow an extra crop and produce surpluses leading to an expanding population and a flourishing civilization but also bringing soil degradation from salt left by evaporation. By the 16th century the Fertile Crescent, was little more than a salty wasteland. 20% of the irrigated land today suffers from salt build up; land lost offsets increased productivity from expanding irrigation. The solution is to use just the amount of water required during the growing season and just enough to leach away salts in the root zone and then to reuse drainage water for crops with a higher salt tolerance such as cotton or tomatoes for canning or paste.

The rise and fall of civilizations closely follows the success and ultimate failure of irrigation. In 1800, global irrigated area was about the size of Austria, while today it is 30 times larger, provides 40% of our food, and is the foundation for feeding 70 million new mouths each year. However, our present day base for food production is highly vulnerable as groundwater is over-pumped and salinization spreads. Increasing land productivity is our main hope at a time when water scarcity and water misuse are the biggest threats to global food production. Food prices are at historically low levels making it difficult to justify new investments in irrigation systems. Many important food-producing regions are sustained by the hydrological equivalent of deficit financing. While water shortages are the main problem, they are compounded by global warming bringing a changing climate, shifting rainfall patterns, and more frequent hurricanes and monsoons. In addition low-lying agricultural land is lost as sea levels rise from thermal expansion of the oceans and melting glaciers and ice caps. Increasing land productivity means extending irrigation to the smallest and poorest farmers, particularly in South Asia and sub-Sahara Africa.

Irrigation will provide the bulk of the additional food needed in the decades ahead, but there is a shift of water away from agriculture to satisfy rapidly growing urban and industrial demands. We have to grow more food with less water; more crop per drop is the agricultural frontier of the 21st century. "There is no obvious, off-the-shelf package available to raise water productivity. This new challenge will require a more diverse and creative mix of strategies that together make agriculture more information-intensive and less resource intensive. - in most cases, by substituting technology and better management for water. But the technologies and strategies described in this chapter inspire hope that we can achieve the doubling of water productivity needed to satisfy the food, water, and environmental needs of the next several decades - if we choose."

Adoption of drip and other microirrigation techniques cut water use and increase crop yields but only 1% of the world's irrigated area uses these methods. If combined with other methods productivity can be greatly improved. "Wuertz pioneered a farming system that combines drip irrigation with minimum tillage of the soil. He buried drip tubing 8-10 inches deep in every crop row, and then practiced multiple cropping of vegetables and field crops (including cotton) along with minimum tillage, leaving the drip irrigation system in place. Studies of Wuertz's low-till drip methods by the University of Arizona showed that the system was able to cut water and energy use by about half and field labor by nearly 60% while increasing lint yield from cotton crops by 13%."

Improved management practices can help farmers reduce water demands while maintaining or increasing crop yields. Weather monitoring and satellite technologies help farmers know when crops need irrigation; pricing water more effectively provides an incentive to farmers to use water more efficiently; improving the ability of crops themselves to use water more efficiently; improving the harvest index to get more edible crop from the same amount of water; breeding or bioengineering plants that photosynthesize in a more water-efficient manner; reuse of municipal waste water for irrigation - these are all part of the solution. Much of the world's grain goes to feed livestock but pork requires twice as much grain per kilo as chicken or farmed fish. Many farmers who are too poor to tap the water a short distance below the surface, a flaw which needs to be remedied by providing them access to affordable irrigation.

Globally the grain harvest is enough but 15% of the world's population cannot afford grain even at today's historically low prices. Very soon food prices will rise, the housewife will complain at the supermarket, and we will see people starving in poor countries. Then people will ask "What went wrong?" The answers are to be found in this book that should be required reading for everyone.

I'm an agronomist and I read this book here in Brazil.As an agronomist,even unemployed today, I must read, about my profession.

If you aren't an expert, this book will be an excelent choice.Irrigation is a very important subject.About 40% of world's food comes from irrigated crops.Even so, only about 15-17% of agriculture in the world is under irrigation.In Brazil, as in USA just about 4% of agriculture, uses irrigation.

This book is concise and very usefull.

I must tell you that this isn't a book for farmers or agronomists.It's for general public reading.

The problem is if you are an expert, about this subject.As an agronomist, I found some minor problems in this book.At first, the author, Ms. Sandral Porcel, even showing irrigations problems in places such as old and new Iraq, communist China, modern Egipt and former Aral sea (now just an useless desert); she doesn't shows how bad government by strong men leaves irrigation, to a terrible result.

Old and new Iraq were ever misfortuned.There was a nature's problem among climate and soil in Iraq.Even so, in any time, terrible government, was the Iraq's rule.Luckly, there's many oil in Iraq, but when this oil will be over, the iraqis will be by far more misfortuned than today.

Communist China was misfortuned by his mad tirant, Mao Tse-Tung.In just 30 years of mad govern, Mao sent to death about 70,000,000 chineses.And irrigation in China, was misfortuned by this mad communist.Today China is by far, at least ten times more rich, but even so, China has no freedom.In fact, China never had any freedom in his thousands years very old history.

Modern Egipt inherited an Allah's gift:Nile and his silt.Every year, Nile rive had a flood.Every year, this flood gave fertilizers and made desalinization.All at no cost, in money or man's labor.In 1960 decade then living Egipt's dictator Gamal A. Nasser, with the USSR's money, support and material made the Assuam dam.Even producing electricity at very low price and puting the anual Nile's flood into history, this dam also finished with profitable fishing in many parts of Egipt.Even bigger problems, that came with this dam are salinization and many deseases.

Former Aral Sea in former USSR was, a terrible chapter in Soviet's ecocide.At least so terrible as Tchernobyl's nuclear nightmare.In 1917, the Aral sea was full of life.Even in 1950 there was a very great and profitable fishing at that sea.With Moscow's orders, almost all water who went to Aral sea was put to be used for irrigation.At terrible eficience's rates of water, the Aral sea began to be over.In 1980 decade, Aral sea was nothing more than a part of history.Hundreds of species of fishs and marine life, all particular, in the World were extincted forever.And the cotton irrigation was producing salted lands, without no profits at all.

Irrigation itself wan't the problem, in any of these cases.The real problem was dictatorship, the lack of freddom.If Egipt is misfortuned by overpopulation or salinization, this come with Islam and his strong man.Islam isn't just a religion.Islam is also a totalitarism.

If you give freedom and education to women, they had less than three children, in average.In Kenia, to example, every adult woman had in average, six children, in 1975.Today they have only about two and Kenia's population is falling.

Egipt under Islam's yoke can't do nothing, except wait the cataclysm, who will come in this Century.Having no education and under Islam and sexual mutilation, women in Egipt are doomed to overpopulate a desert without no future, except poverty, famine and religious fanaticism.

The Egipt's overpopulation and salinization, both came from his religion, not from irrigation itself.The real opposition, in Egipt is linked to VII Century's believes, not to any real possibility of Egipt's betterment.

Irrigation can be a miracle or a cataclysm.All is linked to religion, nature and government.Lack of freedom is the biggest cataclysm's friend.

Sandra Postel's "Pillar of Sand" is a book used as a tool to spread awareness of the world's irrigation problems. These problems include salinization, groundwater depletion, population increase, and competition from urban areas and industry. Postel uses her vast knowledge of the subject in addition to worldwide examples from history and current statistics to illustrate the importance of proper irrigation. If we cannot irrigate more efficiently and moderately, then our world and its civilizations will deteriorate just as the great empires that past.

Reading this book as taught me to be more aware of water and its use or misuse. I learned certain crops couldn't handle the increase of salt found in irrigation water. Groundwater is being used faster than it can be replenished resulting in deeper wells. Eventually the underground water table will be dry. Government irrigations projects seemed to be short-lived attempts to tap the water resources by building large dams, taking water control away from private industries. Cities and industry are now fighting with farmers to gain more than a fair share of the limited water resources. Likewise, downstream river locations are often left dry due to up stream water hording.

People are slowly becoming concerned with our world's water problems and are making strides to prolong the use of this limited resource. Salt tolerant plants are being tested in certain climates. Governments are placing restrictions on water use for farmers and industry. Biogenetically engineered crops can also use salty are smaller amounts of water. Drip irrigation, tube wells, and more efficient irrigation are also ways to save water. Finally, there is more attention to the wildlife in water ecosystems.

and shows our vulnerability as we are trying to feed more and more people with less and less available water. I found it a very educational book.

The 8 billion people Ms. Postel talks about will surely be here come 2030. If we don't have enough water to grow the food they will need famine will be rampant throughout the Mid-East, Southern Mexico and Indonesia. So, Ms. Postel seems to think that drip irrigation and water sharing will prevent this event. When do we face the fact that the forced growth of corporate agriculture has already produced the disasterous growth in world population? And further increases in food production will only contribute to the problem. Stop the destruction of the great aquifers of the world; conserve our precious water, certainly, BUT remember that world population will never be put in balance by growing more food. Solutions to over-population are to be found elsewhere and must be vigorously promoted!