Irrigation dates back to roughly 6000 BC, when the waters of the Nile and Tigris-Euphrates were first diverted to feed farmers’ fields. Today, agriculture consumes 70 percent of the world’s freshwater resources, and irrigation is essential for 40 percent of the world’s food production. Because pumping and distributing water requires large quantities of energy, irrigation is a source of carbon emissions.
Irrigation technologies have evolved to help farmers use water more precisely and efficiently. Both drip and sprinkler methods make water application more exact, delivering as precisely as possible the amount crops need to thrive. With 70 to 90 percent application efficiency, they reduce overall water and energy consumption.
The benefits of drip and sprinkler irrigation are numerous: crop yields improve, costs drop, and soil erosion declines. Lower humidity curtails pests. Surface and groundwater resources are better protected, and conflicts among various stakeholders for water resources may ease. However, both systems require infrastructure and upkeep, which can be expensive, sometimes prohibitively so.
Other practices and technologies can also be effective. Irrigation scheduling and deficit irrigation are two methods of variable application. Sensors can monitor soil moisture and control irrigation systems automatically. Rainwater and runoff can also be captured and put to use.
Technical summaries for each solution will be available May 1, 2017.