This Is How Farmers Are Using Water More Efficiently

As the global population increases and climate change alters rainfall patterns, it’s becoming increasingly important to use water as efficiently as possible. Even now, half of the world’s biggest cities face water scarcity. If our use of water continues on a “business as usual” basis, demand will be 40 percent higher than supply in less than two decades.

Globally, agriculture consumes more freshwater than any other human activity; in the US, it accounts for 80 percent of water consumption. Fortunately, many farmers are implementing technologies and adopting practices that reduce their water use — and it’s making a big impact on their savings. Here’s a look at just a few ways farmers are using water more efficiently:

Hydroponics

Hydroponics is a method of growing crops without soil. Inside a greenhouse, plants sit in a mixture of water and added nutrients, and a pump circulates the water, delivering it right to the plant’s root. Excess water is caught in a reservoir and delivered to other plants in the system. Crops grown in hydroponic greenhouses can be planted closer together because they have smaller root systems as they don’t have to push through soil to find water. They also tend to flower more and produced higher yields. Though it might seem like hydroponics would use more water, it actually uses as much as 10 times less water than conventional, soil-based farming techniques (though water usage depends on the particular system).

Dry Farming

On the opposite end of the spectrum from hydroponics is dry farming. Dry farmers do not use any irrigation; instead, they rely on soil moisture to produce crops during the dry season. The technique likely originated in the Mediterranean, where crops such as olives and grapes thrive under dry farming. In some areas of Europe, dry farming is practically mandated for certain crops. For example, it is against the law to irrigate wine grapes during the growing season as the water dilutes the fruit.

Dry farming relies on particular tilling techniques. During the wetter season, farmers till the soil to create a moist, sponge-like environment for plants to grow. Then, they add a compacted, dry layer of soil on top to effectively seal in the moisture. The plants go on to develop long, deep roots.

Farmers can only grow certain crops with dry farming, and dry-farmed crops usually yield smaller harvests. In addition, dry farming works best with certain soil types and microclimates. For example, along California’s coast, which sees little rainfall during the summer but lots of fog and mild temperatures, dry farmers are able to produce melons, tomatoes, grapes, potatoes, and apples. Interestingly, because they’re stressed for water, dry-farmed crops often boast more intense, concentrated flavors.

Organic

Though many people think “organic” farms simply avoid artificial pesticides and fertilizers, organic agriculture encompasses much more than this. Practitioners of organic farming often think of it as a holistic system of agricultural techniques that protect the local ecosystem — including water resources.

For example, organic farmers often use heavy mulch to reduce the amount of water that evaporates from the soil, and plant cover crops to protect land that would otherwise be left bare. This ground cover offers protection from wind and water erosion, increases organic matter within the soil, and allows more water to seep into the earth. The result is more fertile soil that can hold much more water. Other organic farmers construct nearby bioswales — small, shallow depressions in the ground that capture runoff and allow it to seep into the earth. And of course, because they use fewer fertilizers and pesticides, organic farms reduce the amount of polluted runoff flowing into rivers, lakes, and streams, keeping precious freshwater supplies clean.

Long-term research offers proof of organic farming’s ability to save water. In its 30-year Farming Systems Trial, the Rodale Institute found that organic fields allow 15 percent to 20 percent more water to percolate through the soil and recharge groundwater aquifers. The organic fields in the study were also better able to withstand droughts than conventionally farmed fields because the soil was healthier and could store more water where plants could access it when needed.

Better Technologies

The last few decades have seen a dramatic increase in the number of technologies that give farmers more information about and control over their water use, which can help them to use less overall. For example, sensors embedded in fields can measure soil moisture levels more precisely than the human eye, allowing farmers to know exactly when it’s time to water crops. Some systems enable farmers to monitor fields on a daily or even hourly basis.

Drip irrigation also gives farmers greater control over watering, which reduces water waste. In one form or another, the technique has been around for thousands of years. Where ancient farmers use clay pipes and pots, modern farmers use plastic tubing, pumps, valves, and control systems to deliver water straight to the root of the plant. Drip irrigation reduces the amount of water that’s lost to evaporation; properly installed systems can cut water use by up to 80 percent. Some systems even let farmers control watering down to the individual plant level.

Originally published at markcrumpacker.net on October 18, 2018.