More Crop Per Drop

Part of the Water: H2O = Life exhibition.

While many large farms have the latest harvesting machinery, the farmers often water crops the way people did 5,000 years ago--by running water to the plants through open canals and furrows. This ancient technique turns out to be fairly inefficient, especially in hot climates where farmers lose a majority of the water to evaporation.

In recent years, some farmers have turned to more efficient techniques. In Israel, where water is scarce, engineers invented drip irrigation, which delivers water only where the plant needs it. This and other practices are making it possible to grow more food with less water.

Leveling the Planting Field

By leveling their fields using laser-guided land graders, farmers can ensure that water flows evenly to the plants rather than draining away to lower ground. Another water-saving approach: Leave the dead plants from the previous year on the fields, where they help water filter into the soil.

When water travels down open furrows between rows of plants, only about 45 percent reaches the roots.

A LEPA (Low-Energy Precision Application) sprinkler system sprays water only at the base of the plant, making it much more efficient than furrow methods or wide-area sprinklers.

With drip irrigation, a tube buried in the soil applies precise doses of water directly to the root zone, cutting water waste to nearly zero. However, drip systems are expensive to install and maintain.

By the Numbers

About 10 percent of U.S. farmland is watered with drip irrigation or similar techniques