Engineering R&D: One drop at a time
December 5, 2012
This year’s World Food Prize honors a US-born scientist’s work in reshaping farming practices to make them more efficient and productive by changing the way water is delivered.
Targeted cuts in water use are included in virtually every food and beverage company’s sustainability plan. However, the vast majority of water use in food production occurs on the farm level; agriculture accounts for an estimated 80 percent of overall consumption.
To head off mass starvation, significantly greater agricultural production is required to feed a growing worldwide population. But the challenge is not limited to water consumption: Traditional farming practices contribute to desalination of the soil and increased production of greenhouse gases. Doing more with less is critical to human survival as global population increases beyond 7 billion to a projected 9 billion by 2050, estimates the United Nation’s Department of Economic and Social Affairs.
Daniel Hillel has been in the forefront of judicious reforms in water use and agricultural practices for decades. In recognition of his efforts, he is the 2012 recipient of the World Food Prize, established by Nobel Peace Prize Laureate Norman Borlaug to honor efforts to combat world hunger. Previous laureates include Purdue University’s Philip Nelson, a pioneer in bulk aseptic packaging (see “Crowning achievements in bulk aseptic storage,” Food Engineering, October 2007).
Born in Los Angeles, Dr. Hillel spent his childhood on a kibbutz in the Palestine territory, returning to the US after WWII to complete high school and begin his college education. He received a master’s degree in earth science at Rutgers University before returning to Israel, where he earned his PhD in soil physics and ecology at Hebrew University. An early proponent of drip irrigation, Dr. Hillel became an unofficial irrigation ambassador for David Ben-Gurion, founder of the state of Israel, and served as a land and water management consultant in more than 30 countries in Asia, Africa and South America before taking a position as professor of soil physics and hydrology at the University of Massachusetts in 1977. He has authored more than 200 scientific papers and 21 books, the most recent being Handbook of Climate Change and Agroecosystems, published by World Scientific.
FE: You have been called the father of sustainable water management because of your work in micro-irrigation. Is that a fair characterization?
Hillel: No single individual invented drip irrigation. Modern development traces to the 19th century. The person who came closest to a claim on today’s systems was an Israeli engineer, the late Simcha Blass, who developed the plastic emitter in the 1960s.
For a very long time, the prevailing irrigation paradigm was to flood the land and rely on the ability of the soil to absorb the water. The idea was to saturate the soil with a huge volume, then wait until the moisture depleted before restoring it. In the meantime, moisture stress occurs as the soil gradually desiccates. Rising water tables result in enhanced evaporation at the surface, concentrating salts and resulting in salinization. This type of irrigation is not sustainable. What people don’t realize is that civilizations are often undermined by mismanagement of agriculture and crops.
With the traditional approach, the cost of irrigation was proportional to the number of times the land was irrigated. Pipes and pumps were expensive, as were open canals, but when plastic piping was introduced in the early 20th century, the paradigm began to shift. People tried sporadically to shift toward localized irrigation in the 19th century, but trickle irrigation came into popularity in the late 1960s in Israel. Israelis were not traditional farmers and therefore not bound to traditional methods. Also, water is a precious resource in the desert and very costly, so there was strong motivation to adopt efficient irrigation methods.
FE: When did you become involved with trickle irrigation?
Hillel: I spent part of my youth on a kibbutz in Israel. I loved the open spaces and was fascinated by the interaction of the soil and water to the plants. Irrigation became an avocation and, in time, a vocation.
Drip provides the ability to synchronize water availability with the shifting requirements of the plant: very little water when it is seed, then increasing as needed, all calibrated precisely to the needs of the plant. In time, drip irrigation expanded to become a precision method of delivering nutrients, as well. As a consequence, conservation of both water and fertilizer occurs.
I am an environmental scientist and very concerned about the future of human life. Plant irrigation is part of the environment. The environment is affected by the climate, which is affected by change. Agriculture and feeding a growing population are global issues, and they have to do with ecological systems. Humanity can eradicate nature, or it can adopt more efficient agricultural practices.
FE: How did your association with David Ben-Gurion come about?
Hillel: I joined a band of adventurers when I was about 20 years old. Twelve of us established Sde Boker, the first settlement in the Negev Desert. Three were killed in the first year by marauders. Others joined, and there were 15 after about a year. One day, we saw a military convoy skirting our encampment. The convoy was escorting a Cadillac, which pulled up. The car stopped, and out stepped a man with frizzy hair whom we instantly recognized as David Ben-Gurion. He asked how many were living in the kibbutz, and when we told him, he said, “That’s not enough, you need more people. Are there any age limits? Do you accept elderly couples?”
He then departed to Jerusalem and his government duties. We thought his questions were a joke, but his wife and he returned soon after, and he lived out his life in the village.
FE: You became Ben-Gurion’s immediate supervisor. Was it awkward being the boss of the founder and first prime minister of Israel?
Hillel: He was a grand old man. We had enough work for everyone, such as tending to the young sheep. I was responsible for assigning tasks to Ben-Gurion, but how do you put an old man to work? That was the problem. He was in his late 60s and in a contemplative mood. I was very young, and after the workday, I would visit with him. I had the chutzpah to challenge him, but we had a great relationship.
FE: How did you become Ben-Gurion’s unofficial envoy for drip irrigation in developing countries?
Hillel: Ben-Gurion was visited in the village by U Nu, the first prime minister and a founder of Burma. U Nu was seeking development assistance for the young state. I soon found myself dispatched to Burma with three other members of the village to assist in agricultural development in sparsely populated northeastern areas of the country. Over time, I visited dozens of countries in Asia, Africa and South America, teaching and learning about crop production and water management.
FE: How much impact has drip irrigation had on global agricultural practices?
Hillel: It’s not the only way to apply water, but it is a good way. Both inertia and cost have discouraged wider use of drip.
There’s no one-size-fits-all approach to irrigation: Different circumstances in different locations dictate different approaches. In the US, there was a post-WWII shift to impact sprinklers for surface irrigation. Center-pivot sprinklers spray plants in a circle. Potato farms in the Northwest are a prime example. But those are high-pressure systems for large-scale agriculture. When farmers operate on a small scale and must deal with sloping lands or sand dunes, porous plastic tubes or tubes fitted with emitters are efficient ways to provide a precise response to the plants’ needs. You get much more production: The crop per drop increases.
FE: You are most associated with high-frequency, low-volume irrigation, but your research is much broader, isn’t it?
Hillel: My concern is with all elements of the biosystem: soil, water and air. Agriculture is a net emitter of greenhouse gases. It can be changed to a net absorber, depending on how we manage it. But first we must learn to listen to the earth’s sounds of distress.
FE: You have estimated food production will have to increase 60 percent within 30 years to keep pace with the world’s growing population. Is that possible?
Hillel: I’m not a simpleton or so optimistic that I ignore reality. But with optimism, you can move the world. With pessimism, there is nothing to do but sit down and cry. I preferred to join the ranks of the optimists because I don’t know what to do with pessimism.