Drip Irrigation Systems / Irrigation in the Desert

Drip Irrigation: Growing Crops in the Desert

From Tiny Dynamo: How One
of the World's Smallest Countries Produces Some of the Most Important Inventions
, by
Marcella Rosen

Drip Irrigation, an Israeli invention, allows dry land to produce crops to feed a hungry world.

 

In the words of my generation, let’s get real.

There are now more than 7 billion people coating the surface of Planet Earth, and that number’s going to go up a lot more before it goes down. The rankings of what people consider to be life’s necessities will vary depending on whether they live in Greenwich or Ghana, but the one thing that’s at the top of everyone’s list is water.

Earth is 2/3 water, but only 10% of that is the fresh water we need for drinking, running machinery, growing rice and beans, and shaving and brewing beer and making blue jeans.

Analysts from the UN to the Council On Foreign Relations are painting a fairly grim picture of our ability to keep up with the demand for water in the years to come. The situation is dire – already more than a billion people in Africa and Asia don’t have access to clean drinking water – and the challenge is huge…but it’s not insurmountable.

I suppose that any steps individuals can take to cut down on our use of water would help – shorter showers, less car washing, fewer ice cubes in our mojitos. But when it comes to making a real dent in humans’ use of fresh water, if you’re not talking farming, you might as well not be talking.

Here’s how we humans divvy up the planet’s fresh water: Think of ten glasses of water lined up on a kitchen counter. They represent the world’s supply of fresh water. You drink one glass: that’s the portion people put to domestic use.

Then a factory owner comes in to the kitchen and grabs two glasses: that’s the slice industry uses to do its thing, to cool engines and make paper and fabric and so on. Then a farmer comes in, grabs the remaining seven glasses, takes them back to his farm and pours them on his crops.

That’s right. Seventy percent of the available fresh water on our planet goes to agriculture. And the vast majority of that water is used not only unproductively, but in ways that do more harm than good.

This is the challenge that the legendary Israeli firm Netafim has been confronting since the 1960s – that challenge of bringing agricultural irrigation in line with a drying planet.

“Let’s be clear,” says Naty Barak, a director at Netafim, “most agriculture in the world is not irrigated at all. That’s really poor resource management. The bulk of the irrigation that is done is incredibly inefficient.”

Irrigation breaks down into three main categories: flood irrigation, sprinkler irrigation and the method that Netafim pioneered, drip irrigation.

Flood irrigation (essentially pouring water on crops) accounts for almost 80% of the irrigation that’s done on farms, and according to Mr. Barak, it’s harmful to soil (the water pushes the soil all over the place) and water sources, produces diminished yields, and is wildly wasteful.

The sprinkler family of irrigation devices – used for about 15% of farm irrigation – is a bit better than flood irrigation in terms of efficiency, but that’s not saying much.

Bringing up the rear in terms of usage is drip irrigation, which is the method of choice for about 5% of farms. But it is the unquestionable state of the art in terms of efficiency and its ability to squeeze the most productivity out of every drop of water.

Estimates of the water savings drip irrigation provides vary, largely because watering conditions vary, but they come down between twenty and fifty percent over sprinklers, the next most efficient method. In other words, when it’s really working right, drip irrigation can effectively double your water supply.

Drip irrigation might not sound like your idea of scintillating cocktail party chitchat, but the story of its discovery is a piece of Israeli lore.

Israel isn’t the #1 driest country on earth, but neither is it Seattle. So Israel has more than a bit of history with irrigation. And from the beginning, it was always a matter of moving water around and then turning on the spigot.

In the 1930s, a water engineer by the name of Simcha Blass was visiting a friend in the desert when he noticed a line of trees with one member that was noticeable taller and more robust looking than the others. He did a little digging, literally, and noticed that a household water line running along the tree line had spring a small leak in the area of that one tree and as feeding it with a steady drip drip drip of water. The wet spot on the surface didn’t seem like much, but down below was a large onion-shaped area of juicy soil.

The idea of drip irrigation was born.

Mr. Blass partnered with Kibbutz Hatzerim in the Negev desert to develop entire drip irrigation systems. He tinkered with variations on the idea, but when plastics became widely available in the 1960s, he finally had the ability to put drops of water precisely where he wanted, when he wanted; Mr. Blass and the kibbutz founded Netafim.

Since then, Netafim has sold its systems in more than 100 countries worldwide. And, according to Mr. Barak, the more we ask of our planet’s limited water supply, the more Netafim’s systems will benefit the world.

“Water has been declared to be a basic human right,” he says, “but we squander it with wasteful irrigation. Drip irrigation provides the ability to make water work harder and more productively than its ever done in the past.”

Mr. Barak makes the point that if 15% of farms using conventional irrigation switched to drip irrigation, the supply of water available for domestic use would double.

That statistic alone should make the world take notice. But Netafim’s drip irrigation systems do a lot more than just move water around the farm.

“We’re not just talking about a hose with a hole,” says Mr. Barak. “The system is very sophisticated, because you need to make sure that the plants that are far from the valve get the same amount as the plants that are close to the valve. You have to be able to maintain consistency in a system that runs uphill, that runs downhill…Inconsistency equals waste, and the goal is to eliminate waste.”

Mr. Barak adds that the very idea of water has changed since the company started. “In the 1960s, we were using plain drinking water. Today we use recycled water, waste water, brackish water…and we’re adding nutrients mixed in with the water, so that, in a way, what we’re really doing isn’t irrigation, it’s ‘fertigation.’”

Dirt, nutrients, waste – all of this business going on in the water is what makes controlling it so tricky. And this is where the ingenuity of Netafim comes in – in the valves that control the actual drops of water. The valves are spaced precisely along the irrigation lines, and they must work in concert with one another.

“These valves are what make the system work,” says Mr. Barak. “They are anti-clogging, self-cleaning, very sophisticated little mechanisms. They make it possible to get greater crop yields, greater crop control, while using significantly less water than we did just a few decades ago.

How much less? In 1965 a typical drip irrigation system could use anywhere from two to four liters of water per hour, which was a vast improvement from the prevailing flood irrigation system.

But now, a typical Netafim system will use half a liter per hour…and Netafim is still trying to get that number down.

The main reason, Mr. Barak explains, is simple. “In the next 100 years we are going to have to produce more crops than we ever have, with far less environmental damage than we’re doing now.”

Some are well on the way to achieving that goal. About 75 percent of Israeli farming is done with drip irrigation, with practically no flood irrigation at all. Drip irrigation accounts for about half of irrigation in California; South Africa is also a big user.

But other areas of the world have yet to make the shift – and food is only one of the reasons why it’s important for them to do so. Because when you really dig in to the nuances of drip irrigation, you start to see how widespread its ramifications are.

For example, by using water more efficiently, drip irrigation means you use less fertilizer. Fertilizer production is a significant source of greenhouse gas emissions.

Likewise, the growing market for biofuels will benefit from drip irrigation through the reduced cost of raising fuel crops. which will in turn aid in the spread of biofuels, which will reduce the production of greenhouse gasses, which will, in the long run, reduce the pressure on the world’s water supplies.

There’s also a quality of life issue at stake here – and I’m not talking about watering lawns. There are places where the challenge is not managing water, but simply getting it. Netafim is in some of these places, and the changes they have made are remarkable.

Mr. Barak tells of one Kenyan village where the women spent the bulk of their day carrying water from a small lake to the fields. With a drip irrigation system in place, not only are they realizing far higher crop yields, but the women are now freed up to spend their time far more productively than they were before…getting an education, for instance.

It’s an open question whether we can push our existing water supplies to provide us with the food – let alone the ice cubes – to which we’ve become accustomed. But Netafim has already demonstrated an ability to take a productive technology and keep pushing it well beyond its initial boundaries. There’s no reason to think they can’t do the same for the world’s existing water supply.