We all know that there’s the potential for great water efficiency—and equally great water squandering—in agricultural irrigation. After all, anyone who’s been following our coverage on water footprints (or downloaded our free iPhone/iPad app—Waterprint) is aware of that the amount of water needed to grow our fruits and vegetables can vary wildly; from 25 gallons of water for a pound of eggplants to 379 gallons for a pound of figs1. But did you know that it takes double the water to grow the same amount of wheat in Russia as it does to irrigate that same crop in France?
That last bit of information comes courtesy of an interview with Sander Zwart, and researchers at Delft University of Technology in The Netherlands, as part of the New York Times (NYT) coverage on the development of new technology—which Zwart calls “Watpro”(short for water productivity)—designed to establish water use standards for a variety of crops around the world as a way to help farmers “optimize” their water resource management.
Zwart developed this technology—which involves the use of satellite data, water sensors, and other environmental data—to give farmers a complete picture of how much water they need and use, and whether or not that ratio is efficient as compared to other growers. After a 10-year study of the world’s largest wheat-producing countries, Zwart and his team have come up with a set of tools that measure water productivity (defined as the amount of crop produced based on the amount of water used), based on evaporation and yield data provided by remote sensing and satellite images. According to the NYT, this data will highlight “where water is used productively and where it is squandered. Reasons for wasted water can be analyzed, allowing farmers, and agricultural policy makers, to establish best practice for irrigation in specific locations, with the aim of cutting down on water use without compromising the harvest.”
The study was conducted using the following standards:
* To avoid skewed results as a result of “ highly localized anomalies, the study was conducted on sample areas of at least a square kilometer, or 247 acres.”
* The square kilometer areas studied were made up primarily of irrigated field systems because of the difficulty involved in measuring and managing rain-fed systems.
* Crop yields were determined by weight (rather than nutritional value) because the system itself was not designed to analyze nutritional value.
Although the Watpro does not actually give farmers specific instruction on how to increase their water productivity, Zwart tells the NYT that he believes the data could be used to create incentives to encourage the adoption of water efficiency techniques and standards while also pressuring agricultural interest to use freshwater resources judiciously.
So what do you think? Could the right incentive convince small farmers to switch to expensive water-saving technologies in order to increase efficiency? On the other hand, is it enough that Watpro is best suited for, as the NTY describes it “low-risk, large-scale industrial farming,” or should the focus be on all farming, large and small? Finally, should any “best management practices” standard for agricultural irrigation include the many other elements that contribute to and effect agricultural water use; including fertilizers, soil types, and alternative water sources (rainwater catchment, desalination)?
1 Water footprint totals provided by www.waterfootprint.org/?page=files/NationalWaterFootprint.